Standing and Probabilistic Injury

Curtis A. Bradley* & Ernest A. Young** June, 2024

Standing to sue often turns on questions of probability. For example, public law plaintiffs must show that they are likely to be affected by allegedly unlawful government surveillance or environmental policies, and consumers may wish to sue private defendants over false credit reporting or data breaches that may or may not cause them financial or reputational harm in the future. This Article offers a framework for resolving a wide range of these “probabilistic standing” issues. Our core claim is that courts and commentators ask too much of standing doctrine in probabilistic cases. First, scholars sometimes seek a unified theory of probabilistic standing to cover categories of cases that ask distinct questions, such as cases involving who is subject to a challenged action, on the one hand, and those involving whether a person subject to such an action is sufficiently likely to be harmed, on the other. Second, courts should not ask how probable elements of a plaintiff’s case must be in order to support standing, but rather who should decide whether a given probability is sufficient. Judges and parties struggle in litigation to assess the actual probability of occurrences, and Article III of the Constitution provides no standard for how probable an injury must be to support a lawsuit. Third, any doctrinal probability threshold for standing would encounter a related problem, which is that the probability of an injury depends significantly on how that injury is framed. Which harms “count” for standing is thus a vital question in assessing the probability of injury, but Article III is an unlikely place to look for answers. Within certain constraints, courts should look instead to the underlying substantive law to define the relevant injuries for standing purposes. Finally, we contend that many of the concerns associated with probabilistic claims are better addressed through the law of remedies and prudential elements of the timing doctrines (mootness and ripeness) than through the constitutional law of standing.

Introduction

The Supreme Court’s docket continues to be preoccupied with issues of standing to sue. In the 2022–23 Term, for example, some of the Court’s most significant decisions—concerning, for example, affirmative action, student-loan forgiveness, immigration enforcement, and Indian affairs—had to address questions of standing, with varying results.¹ The 2023–24 Term similarly had a number of important standing cases.² This is unlikely to change any time soon. Just a few years ago, the Supreme Court decided what may be its most important standing decision in a generation—TransUnion LLC v. Ramirez.³ Instead of settling the law of standing, however, TransUnion left in its wake a host of questions that are creating disagreements in the lower courts.

A central issue in the law of standing, directly implicated in TransUnion, is how the law should address situations in which a plaintiff’s injury is uncertain. When someone challenges actions that may injure them in the future, they must establish a likelihood that those injuries will in fact occur.⁴ Even when someone complains of present or past injuries, they must still demonstrate to the court’s satisfaction both that the defendant’s action is the likely cause of their injury and that the relief they request is likely to redress it.⁵ Some of these questions have now acquired a distinctive label—“probabilistic standing.”⁶ As one commentator notes, “[D]etermining when a claim is too remote or speculative to support standing has occupied substantial attention of the Supreme Court, perhaps more attention than any other question of justiciability.”⁷ Not entirely surprisingly—given the critical tenor of much academic writing on standing—the doctrinal results have been weighed in the balance and found wanting.⁸

Issues of probability arise throughout public and private law litigation. Plaintiffs may challenge government policies relating to surveillance, environmental protection, or public health well before it is certain whether or how they will be affected by those policies.⁹ Efforts by beneficiaries of regulation to compel the government to better enforce the law—concerning environmental protection, consumer safety, non-discrimination, and many other topics—often turn on probabilistic assessments of whether such enforcement would make a difference.¹⁰ In private litigation, standing to pursue products liability claims may depend on assessing the degree of risk that an alleged product defect presents.¹¹ Standing to sue for data breaches or false credit reporting may require establishing the likelihood that the breach or false reporting will cause harm.¹² Suits relating to unfair competitive behavior (including false advertising and trademark infringement) frequently turn on probabilistic claims about the likely effect of such behavior on the decisions of potential customers.¹³

This Article offers a framework for resolving a wide range of probabilistic standing issues—some emerging in TransUnion’s wake, others having frustrated scholars for a generation.¹⁴ Our core claim is that courts and commentators tend to ask too much of standing doctrine in probabilistic cases.

First, courts and commentators sometimes seek a unified theory of probabilistic standing to cover categories of cases that actually ask distinct questions.¹⁵ These categories include cases asking who is subject to a challenged action, on the one hand, and cases asking whether a person subject to such an action is sufficiently likely to be harmed, on the other. Courts tend to reach different outcomes in these two sorts of cases, although they rarely acknowledge the difference or explain why it matters. A third category of probabilistic cases concerns uncertainties about whether the defendant’s action has caused or will cause the plaintiff’s injury (or whether the requested relief can redress it). These uncertain causation cases tend to turn on considerations involving separation of powers and the role of the jury, rather than assessments of probability alone.

Second, courts should not ask how probable elements of a plaintiff’s case must be in order to support standing, but rather who should decide whether a given probability is sufficient. Judges and parties struggle to assess the actual probability of occurrences in litigation, and in any event, Article III provides no standard for how probable an injury must be to support a lawsuit. Determining which institution has primary responsibility to make a particular judgment is a more familiar and tractable problem for courts.¹⁶

Courts that attempt to set a probability threshold for standing encounter a third and related problem, which is that the probability of an injury depends significantly on how that injury is framed. A person whose private information has been wrongly disclosed through a data breach, for instance, may wish to sue before any concrete consequences arise based on a concern about future harm. That harm may seem remote, but if being wrongfully subjected to a risk of harm in the future counts as harm in itself, then the plaintiff’s present injury is certain. Or she may experience other present harms, such as anxiety or the need to undertake costly precautions against identity theft. Which harms “count” for standing is thus a vital question in assessing the probability of injury, but Article III is an unlikely place to look for answers. Within relatively modest constraints, courts should look instead to the underlying substantive law to define the relevant injuries for standing purposes.

Finally, we contend that many of the concerns associated with probabilistic claims are better addressed through the law of remedies and prudential elements of the timing doctrines (mootness and ripeness) than through the constitutional law of standing. There is no reason, for example, to develop a mini-ripeness doctrine assessing an injury’s “imminence” for standing purposes when existing ripeness jurisprudence is better suited to the task. Asking standing doctrine to do less work, we argue, will make it more coherent and predictable. Our framework is consistent with TransUnion, which we contend some courts and commentators have read too expansively.

Many circumstances conspire to make consistency in standing doctrine elusive. The stakes in standing cases—access to court for the plaintiff, a dismissal at the threshold for defendants—create powerful incentives to raise the issue in a vast number of cases and explore every ambiguity or inconsistency in the doctrine. At the same time, standing always appears in cases that are fundamentally about something else—the merits—and we accept the widespread view that standing principles can never exist wholly apart from the substantive law governing that vast and diverse range of cases. Moreover, the Supreme Court’s recent standing decisions reflect not one consistent voice but an assortment of Justices thinking about standing from a variety of perspectives. No one should expect the cases to neatly fall into line. But some coherence is still possible by focusing on the core principles and underlying goals of the doctrine.

Unlike much valuable writing about standing, we do not aim to rethink the law of standing from the ground up or suggest a radically different approach. Our aim instead is to develop a coherent account of standing doctrine that is derived from, and largely consistent with, the existing case law.¹⁷ Such an account, we hope, will guide courts and help lawyers predict outcomes in future cases. Consistent with this approach, we accept the requirement of an “injury in fact,” something that has sharply divided commentators but has repeatedly been endorsed by the Supreme Court as a bedrock of modern standing law.¹⁸ We maintain that this requirement restricts standing considerably less than the commentary sometimes suggests.

Any effort to render a field of doctrine coherent, however, is bound to identify mistakes, inconsistencies, and points in need of reform. We contend that several leading Supreme Court decisions have been read to decide far more than they actually did. For example, many courts and commentators have treated Clapper v. Amnesty International U.S.A.¹⁹ as the leading case on probabilistic standing,²⁰ but we see it as relevant only in limited circumstances in which uncertainty over whether the plaintiffs have been subjected to the policy they challenge cannot readily be resolved. We also contend that the “remedial standing” rule, which requires plaintiffs to establish standing separately for each remedy sought, is a misinterpretation of the decision in City of Los Angeles v. Lyons;²¹ that case should instead be understood as recognizing that the sorts of injuries that suffice for standing may vary depending on the remedy sought.²² In other areas, the Supreme Court has expressed uncertainty that we endeavor to clear up. The Court and some commentators have doubted whether a meaningful difference divides standing and ripeness,²³ but we explain why that distinction is valuable. Accordingly, our most far-reaching proposal would largely abolish a freestanding “imminence” requirement for standing because the ripeness doctrine better serves the same function by asking questions that are more manageable for courts. Each of these positions is to some extent inconsistent with what the Court has said in certain cases, but we contend that they largely align with—and better explain—what the Court has actually done.

We begin, in Part I, with an overview of the probabilistic injury problem and an outline of our proposed framework. Part II addresses cases in which it is uncertain whether plaintiffs are exposed or subject to the allegedly unlawful practices they challenge. Part III considers plaintiffs who are subject to such practices but cannot establish with certainty that they will be harmed or when such harm will occur. This Part is the heart of our analysis, and it deals with the extent to which Article III permits Congress to render certain aspects of probabilistic harms actionable by statute. Part IV considers the role of both the law of remedies and the timing doctrines, especially ripeness, in relation to standing.

I. Reframing Probabilistic Standing

The term “probabilistic standing” is sometimes used to denote a relatively narrow set of cases that focus on how likely an injury must be to support litigation in federal court.²⁴ The scope of the issue is, in fact, much broader. Whenever standing to sue under Article III is contested, the dispute typically involves whether the plaintiff’s injury is the sort that counts for Article III purposes, whether that injury is sufficiently likely to occur, or whether the causal link between that injury and the defendant’s conduct suffices to establish traceability and redressability.²⁵ Issues of likelihood and causation are probabilistic on their face. And because the probability of an injury varies according to how that injury is defined, the question of what injuries count is inextricably linked to probability problems. One cannot talk about probabilistic standing without touching on the most basic issues in Article III standing doctrine.

A. Injury in Fact and the TransUnion Case

Standing’s basic catechism is familiar: To satisfy the “irreducible constitutional” requirements for standing, “[t]he plaintiff must have (1) suffered an injury in fact, (2) that is fairly traceable to the challenged conduct of the defendant, and (3) that is likely to be redressed by a favorable judicial decision.”²⁶ Injury in fact requires “ ‘an invasion of a legally protected interest’ that is ‘concrete and particularized’ and ‘actual or imminent, not conjectural or hypothetical.’ ”²⁷ The injury need not be large; as one court of appeals recently put it, “[a] concrete injury need be only an ‘identifiable trifle.’ ”²⁸ Many scholars have noted that the case law’s references to “a legally protected interest” or a “judicially cognizable injury”²⁹ establish that what counts as injury in fact is a legal question as well as a factual one.³⁰

In Spokeo, Inc. v. Robins, the Supreme Court explained that “particularized” and “concrete” are separate concepts. The former means that the injury “must affect the plaintiff in a personal and individual way,” and this can be true even when a large number of people suffer the same injury.³¹ The latter element, concreteness, has proven trickier to define. The Court has explained that “ ‘[c]oncrete’ is not . . . necessarily synonymous with ‘tangible,’ ” but a concrete injury “must be ‘de facto’; that is, it must actually exist” and be “ ‘real,’ and not ‘abstract.’ ”³² The Justices have divided, however, over exactly how “real” an injury must be, and in particular whether a purely legal injury can suffice.³³

The Justices grappled with these concepts at some length in TransUnion LLC v. Ramirez.³⁴ The case involved the Fair Credit Reporting Act (FCRA), which requires consumer reporting agencies to accurately report information about individuals.³⁵ A class of 8,185 consumers alleged that a credit reporting agency erroneously included an alert in their files that the consumer’s name matched a watch list for terrorists and other serious criminals maintained by the Treasury Department’s Office of Foreign Assets Control (OFAC). Mr. Ramirez, a named plaintiff, was denied a loan to purchase a car by an auto dealership based on a false OFAC alert. For 1,853 of the class members, the complaint alleged that TransUnion provided misleading credit reports to third-party businesses. For the remaining 6,332 class members, the erroneous information was included in their credit reports but not provided (during the class period) to any third parties.³⁶

The FCRA conferred a right to sue for statutory damages on all of these persons.³⁷ The Court, however, distinguished between (a) Mr. Ramirez, who suffered consequential injury from the erroneous report; (b) 1,853 class members, who could claim an intangible injury to their reputation from distribution of the erroneous OFAC alert but not any identifiable consequences; and (c) 6,332 class members, who could show only a violation of their statutory right not to have the erroneous information included in their file. The Court held that Ramirez and the 1,853 class members had “actual” injuries under Article III, but the largest group did not.³⁸

TransUnion considered both which injuries count and how probable those injuries have to be under Article III. Not all phenomena that people experience as harmful count for standing, and courts must make legal judgments about which injuries suffice.³⁹ All of the TransUnion plaintiffs had incorrect information in their credit files kept by the defendant, violating each plaintiff’s legal rights under the FCRA, but only Ramirez had experienced any consequences on account of this legal violation. The Court said that purely legal violations did not amount to “actual” injury, and it distinguished between plaintiffs whose tainted credit files had been accessed by third parties and plaintiffs whose files had not been accessed. The closest analogous injury recognized at common law was reputational harm under the tort of defamation, the majority reasoned, and this harm is actionable only when damaging information is disseminated to third parties.⁴⁰

The probability question arose because the TransUnion plaintiffs argued that simply having wrong information in their files created a risk of reputational harm (and consequential damage) down the line. The Court rejected this argument, holding that, in a suit for damages, “the mere risk of future harm, standing alone, cannot qualify as a concrete harm—at least unless the exposure to the risk of future harm itself causes a separate concrete harm.”⁴¹ Only harm that has already materialized, the Court suggested, amounts to concrete injury in fact necessary to support standing to seek damages in federal court.⁴²

The injury-in-fact requirement remains quite controversial in the academy.⁴³ Critics have emphasized that injury in fact emerged as a constitutional requirement for standing only in the last half-century, beginning with the Court’s 1970 decision in Data Processing.⁴⁴ Prior to that decision, the Court had applied a legal injury test turning on whether the underlying law invoked by the plaintiff conferred a legal right to sue.⁴⁵ Data Processing evidently meant “to simplify and liberalize the standing inquiry” by making “[l]ayman’s injury . . . rather than legal or ‘lawyer’s’ injury . . . the linchpin.”⁴⁶ But as Congress enacted environmental, consumer protection, and other federal regulatory statutes with citizen suit provisions expressly authorizing private lawsuits, the factual injury requirement came to be seen as unduly restricting Congress’s power.⁴⁷ Critics have typically argued that Article III should be satisfied whenever the plaintiff has a valid cause of action—a version of the old legal injury test.⁴⁸

Academic frontal assaults on the injury-in-fact requirement have, however, gained little traction at the Supreme Court. In recent years, all the Justices signed on in various opinions to the standing doctrine as articulated in the modern case law, including the injury-in-fact requirement. Moreover, the differences between the Justices over application of the doctrine are often exaggerated. It is noteworthy, for example, that all the Justices agreed in TransUnion that there was standing for class members as to whom false reports had been submitted to third parties. In one of the student loan-forgiveness cases from 2023, the Court was unanimous in applying the modern standing framework, despite being divided in a companion case about the merits of the dispute.⁴⁹

We thus accept in this Article the basic requirement of injury in fact, as well as the principle from Lujan and TransUnion that the Constitution constrains—to some meaningful degree—Congress’s authority to create standing by conferring statutory rights to sue. Our exploration of the probabilistic injury problem proceeds within that framework. As will be evident, we read the cases to afford Congress considerably more discretion and flexibility than is sometimes appreciated. We contend that the significant challenges that undeniably exist within standing doctrine can best be handled through a more nuanced revision of existing principles rather than a wholesale reinvention of the jurisprudence.

B. The Probability Problem

Originally, the phrase “probabilistic standing” described a particular scenario aggregating large numbers of persons or incidents to establish a statistical likelihood of some injury to at least one plaintiff, even though it might be impossible to be sure which one. In Summers v. Earth Island Institute, for example, a group of environmental organizations challenged new Forest Service regulations exempting certain small fire-rehabilitation and timber-salvage projects from a notice, comment, and appeal process employed by the Service for more significant land management decisions.⁵⁰ Plaintiffs had initially challenged a particular decision, the Burnt Ridge Project, and they established standing by showing that one of the plaintiff organizations’ members had repeatedly visited the Burnt Ridge site and had imminent plans to do so again in the future.⁵¹ Things got interesting, however, when the plaintiffs settled their dispute with regard to that particular project but wished to continue their challenge to the general regulation exempting such small decisions from the Service’s prior procedural obligations. Writing for the majority, Justice Scalia denied that “when a plaintiff has sued to challenge the lawfulness of certain action . . . but has settled that suit, he retains standing to challenge . . . the regulation in the abstract . . . apart from any concrete application that threatens imminent harm to his interests.” Allowing such an abstract suit, he explained, “would fly in the face of Article III’s injury-in-fact requirement.”⁵²

In so holding, the Court in Summers rejected what it dubbed a “probabilistic standing” argument advanced by Justice Breyer’s dissent. Breyer thought that the plaintiff organizations had shown that they were virtually certain to have some members affected by some wrongful timber sales at some point in the future. After all, he noted, “[t]he Complaint alleges, and no one denies, that the organizations, the Sierra Club for example, have hundreds of thousands of members who use forests regularly across the Nation for recreational, scientific, esthetic, and environmental purposes.”⁵³ In other words, although the plaintiffs could not establish which members would be affected by the next allegedly unlawful timber sale, some member of at least one of the organizations would have the requisite contact with an allegedly unlawful act by the Service. Because the Forest Service’s rules change applied so broadly, and the plaintiffs had so many members tromping about in virtually all the nation’s national forests, Breyer concluded that standing was certain even without knowing where or when the next timber sale would take place.⁵⁴

The Summers dissent presented a particularly explicit instance of standing based on probabilistic assessments, but similar difficulties occur in a wide range of more familiar contexts. Persons wishing to challenge government surveillance may be uncertain whether they have actually been spied upon.⁵⁵ Individuals who have bought a car with a defective component may not know when or whether that component will fail—or whether and how badly such failure might injure them.⁵⁶ Persons exposed to a hazardous chemical or unsafe food products may not know whether such exposure will actually result in injury.⁵⁷ Victims of police abuse may have a hard time showing that they are likely to be subjected to abusive policies again.⁵⁸ Commentators argue that probabilistic approaches to these sorts of problems are “necessary to address risks that pose concrete injuries to many people,”⁵⁹ and the lower courts have sometimes—but not always—accepted them.⁶⁰

Probability problems are not limited to the injury prong of standing doctrine. Consider Allen v. Wright,⁶¹ in which parents of black children enrolled in public schools challenged the Internal Revenue Service’s failure to enforce rules making donations to private schools engaged in race discrimination non-tax deductible. The Court had little problem concluding that the plaintiffs were injured by the slow pace of desegregation in their public schools. However, the Court was unwilling to accept the plaintiffs’ causation theory tracing that injury to inaction by the IRS.⁶² Lax enforcement by the IRS, the plaintiffs said, undermined public desegregation efforts by effectively encouraging donations to private schools, thereby allowing those schools to charge lower tuition and encourage white flight.⁶³ That theory depended on a large number of intervening decisions by third parties not before the court—donors, private school administrators, parents of white children—that were to at least some degree speculative.⁶⁴ Those independent variables precluded the conclusion that plaintiffs’ injuries were definitively traceable to the IRS’s conduct and created doubt as to whether ordering the IRS to change its enforcement practices would redress the plaintiffs’ injury.⁶⁵

Similar problems arise when it is uncertain whether a product defect or chemical exposure caused a tort plaintiff’s injury, or when plaintiffs ask a court to order a regulatory agency to regulate practices that may cause long-term environmental harms. Or one may be confident that enforcement of a particular law or policy would cause injury, but it may be uncertain whether or when that law or policy will be enforced.⁶⁶ These problems of probabilistic causation and enforcement are important, and we hope to address them in future work. But because we view them as requiring somewhat different doctrinal solutions, our principal focus here remains on probabilistic harms and the extent to which they can satisfy the core requirement of injury in fact.

Probabilistic injury is not just—or even primarily—an issue in the law of standing. Whether injury will occur in the future, or whether the defendant’s action caused the plaintiff’s past or ongoing injury, is also a question both on the merits (is the defendant liable to the plaintiff?) and at the remedial stage (can the plaintiff show a sufficient likelihood of harm to justify a preventive injunction?). This overlap requires some coordination between standing doctrine and the substantive and remedial law, and sometimes between different institutions. For example, standing is a threshold issue decided by the judge, but a definitive standing ruling that the defendant’s conduct actually did injure the plaintiff could preempt the jury’s prerogative to decide the merits. Conversely, established doctrines limiting the availability of injunctions to prevent harms may adequately deal with many concerns about probabilistic future injuries, without having to reinvent the wheel in the context of standing doctrine.

C. How to Assess Probabilistic Injury (and How Not to)

Article III standing doctrine combines three sets of underlying imperatives and values. The first is historical continuity. The text of Article III gives courts relatively little to work with: it speaks to “cases,” “controversies,” and “judicial power.”⁶⁷ The Justices have long said, however, that “[i]n endowing this Court with ‘judicial Power’ the Constitution presupposed an historic content for that phrase,”⁶⁸ confining federal jurisdiction to “cases and controversies of the sort traditionally amenable to, and resolved by, the judicial process.”⁶⁹ The Court has combined originalist and traditionalist approaches to this history, and it has supplemented historical constraints grounded in common law practice with other concerns.⁷⁰ In general, the upshot has not been to lock in particular practices existing at the Founding—for example, no one thinks that Article III requires federal courts to retain the common law forms of action or to prevent significant innovations such as the class action. Rather, the Court’s historical analysis has tended to require that modern litigation simply retain certain basic elements that have characterized the core of Anglo-American justice.

Historical considerations coexist in standing jurisprudence with separation of powers and prudential concerns. For many years, the Court has insisted that “[t]he ‘case or controversy’ requirement . . . defines with respect to the Judicial Branch the idea of separation of powers on which the Federal Government is founded.”⁷¹ The Court in TransUnion reaffirmed this imperative, opining that “the concrete-harm requirement is essential to the Constitution’s separation of powers” because “[a] regime where Congress could freely authorize unharmed plaintiffs to sue defendants who violate federal law not only would violate Article III but also would infringe on the Executive Branch’s Article II authority.”⁷² More broadly, standing requirements protect both of the political branches by limiting the courts’ occasions to exercise the power of judicial review.⁷³

Finally, separation of powers considerations shade into institutional prudence in standing doctrine, which expresses “the proper—and properly limited—role of the courts in a democratic society.”⁷⁴ These concerns caution courts to act with restraint in order to preserve their legitimacy.⁷⁵ They also encourage courts to withhold decisions in circumstances where they may not be in a position to issue a sufficiently informed decision.⁷⁶ As Professor Fallon has explained, “A specific and concrete injury helps frame issues in a factual context suitable for judicial resolution,” limits “the scope of a judicial decision,” and promotes the “adverse interests and arguments [that] sharpen ‘the presentation of issues upon which the court so largely depends for illumination of difficult constitutional questions.’ ”⁷⁷ As we will see, these concerns frequently constrain the timing of litigation as well as its permissibility.

This mix of historical continuity, separation of powers concerns, and institutional prudence complicates any effort to construct a straightforwardly originalist jurisprudence of standing. Orienting the doctrine around history only—or focusing solely on separation of powers or prudential matters—would require rejecting a great deal of precedent, something that the Court has understandably been unwilling to do. Nor would it be consistent with the Founding generation’s decisions to rely on the common law and empower Congress, decisions that allowed for considerable flexibility.⁷⁸

Thinking of these three elements in combination helps explain why the Summers majority rejected Justice Breyer’s argument for probabilistic standing. The argument relied on the law of large numbers: Outcomes that may be merely probable in isolation become nearly certain to occur if the experiment is tried a large number of times.⁷⁹ If injury is simply a formal requirement grounded only in history, it is hard to see why Breyer was wrong to find it met in Summers. The large number of members in the plaintiffs’ organizations, the allegation that they visited every national forest, and the large number of timber sales that would be affected by the new Forest Service rules meant that some plaintiff, somewhere, was bound to visit an area affected by the rule sometime in the relatively near future. Similar arguments could be made, however, in many circumstances where procedural aggregation mechanisms—including not only organizational standing but also class actions and (possibly) multi-district litigation—yield large numbers of plaintiffs. That would threaten the separation of powers value of standing doctrine in limiting the opportunities for judicial intervention in public disputes.⁸⁰ Standing based on aggregated probabilities of injury might likewise turn private litigation among small numbers of private parties into effectively public disputes with potentially broad regulatory consequences for society.

The prudential problems are even more compelling. From that perspective, the function of standing is to ensure a concrete frame for the litigation around a particular plaintiff affected by a particular government action. That frame permits a court to see how a challenged measure plays out in real circumstances and hear from real people about how they have been affected. Probabilistic standing cannot supply that frame. Justice Breyer’s argument demonstrated that some plaintiff would be affected by some application of the challenged policy, but it could not tell the court who, where, when, or precisely how. The challenge in Summers remained fundamentally abstract, despite the mathematical near certainty of injury.⁸¹ It is hardly surprising that the majority chose to await a less conceptual plaintiff.⁸²

Against this backdrop, our approach parts company with the predominant thinking about probabilistic standing in three ways. First, we contend that courts should not attempt to set a probability or proximity threshold as a matter of standing doctrine; rather, they should simply rely on the usual pleading standards to ensure that a claim is properly presented. This issue cuts across a wide variety of cases. In Clapper, the Justices sparred over whether a threat of future injury must be “certainly impending” or “reasonably probable.”⁸³ Similarly, a leading circuit decision on data breaches evaluated standing by identifying three factors that would increase the likelihood that purloined information would someday be used to the detriment of plaintiffs.⁸⁴

Commentary has generally agreed that the relevant question is to assess the likelihood of harm that Article III requires. Jonathan Remy Nash argues that federal courts should consider the “expected value” of an injury—that is, its probability multiplied by its impact—and recognize a plaintiff’s standing as long as that value is positive.⁸⁵ Under this test, any risk of a genuine harm would suffice, however low the risk or trivial the harm. Andrew Hessick would drop any probability requirement altogether, thereby allowing standing to sue for “all claims involving a risk of future injury.”⁸⁶ Although they allow standing for any assertion of a risk of future injury in principle, these authors would each impose a prudential limit to weed out small risks of injury—thereby reopening the question of where exactly that threshold should be set.⁸⁷ We doubt that this question can be answered in a nonarbitrary way.⁸⁸

Any effort to set a uniform probability threshold in probabilistic cases overlooks important differences between classes of cases. And courts will struggle to evaluate objective likelihoods of future injury or, more importantly, to draw a necessary probability threshold out of Article III. Courts should instead focus on defining injuries with more consistency and precision, which would dissolve some difficult imminence questions and, at least, simplify others. Once the injury is properly defined, courts should ask only that it be pled with the precision and support that any other factual allegation requires.⁸⁹ The pleading standards after Twombly and Iqbal are hardly toothless,⁹⁰ and the Supreme Court has made clear that allegations going to standing “must be supported in the same way as any other matter on which the plaintiff bears the burden of proof.”⁹¹ If plaintiffs have pled with sufficient particularity that they were injured in a cognizable way, those allegations should be taken as true rather than subjected to some threshold probability standard drawn from the penumbra of Article III.⁹²

The second departure involves carefully defining the plaintiff’s injury but does not look to Article III for a catalog of cognizable harms. What injuries count is crucial: If purely legal injuries count, for example, then legislatures could obviate worries about the probability of factual harm by defining legal wrongs. Alternatively, some lower courts have held that subjecting someone to a risk of future injury can itself be a cognizable harm for standing purposes.⁹³ TransUnion sharply limited standing based on legal injury or exposure to risk,⁹⁴ but it did not otherwise look to Article III to prescribe which injuries count.

As we explain, Article III rules out some forms of harm as injuries in fact and accepts others—such as physical injury or financial loss—as sufficient without further inquiry. The most interesting category includes those harms that are not universally cognizable but may, depending on the state of the underlying law, suffice for injury in fact in particular circumstances. TransUnion acknowledged that present harms arising from exposure to risk, such as emotional distress, may count as injury in fact.⁹⁵ Standing doctrine should not rule out these sorts of injuries when the underlying law makes them immediately cognizable—for example, where creation of a risk violates a warranty or some other contractual provision.⁹⁶ Our argument thus emphasizes the underappreciated extent to which the substantive law governing a plaintiff’s claim remains crucial in defining the interests that count for standing.

Third, once the plaintiff’s injury has been appropriately defined and plausibly pleaded, courts should deal with uncertainty as to when or if future injuries are likely to occur through the timing and remedial doctrines. Standing asks whether the plaintiff is the right party to make a particular claim, not whether that claim is likely to be successful. It should not require some sort of mini-trial at the threshold. Allegations of uncertain or distant future injuries may, however, impede a court’s ability to decide a case effectively. The court may not have all the necessary information to decide the legal issues presented, for example, if it does not know when or how the asserted injury will manifest.⁹⁷ Moreover, in constitutional cases, judicial legitimacy might best be preserved if courts avoid exercising their power of judicial review until such exercise is genuinely needed.⁹⁸

These sorts of concerns are largely prudential, and the doctrine of ripeness—and sometimes of mootness—has the requisite flexibility to deal with them.⁹⁹ There is little advantage, and considerable confusion, to having a second ripeness doctrine operating within the injury requirement itself.¹⁰⁰ And to the extent that timing doctrines are more prudential in nature than standing, they afford legislatures a potential say in determining when risks of future harm are adjudicated. Similarly, the law of remedies both informs the meaning of standing doctrine and provides an independent check on remote or unlikely harms. Remedial doctrines can and should be left to operate of their own force in many cases.

II. Uncertain Exposure

The Supreme Court has frequently suggested that plaintiffs regulated by or subject to allegedly unlawful action will nearly always have standing to challenge it; any difficulties will typically concern the timing of litigation or the appropriate remedy.¹⁰¹ In public law litigation, the government’s regulation of private actors generally involves coercive action presumptively subject to judicial review.¹⁰² Similarly, standing is rarely a problem in private litigation when the plaintiff is clearly exposed or subject to the challenged behavior, even when the causal link to actual harm is contested on the merits. As we discuss in Parts III and IV, allegations that such actions will cause future harm may encounter arguments that the suit should await the manifestation of an injury. But what if it is unclear whether the plaintiff has ever been subject to the challenged action, or ever will be in the future? Plaintiffs have struggled to establish standing in this scenario.¹⁰³

Our discussion here distinguishes between two sorts of cases. Clapper v. Amnesty International, USA illustrates a category of undisclosed exposure in which plaintiffs do not and perhaps cannot know whether they have been subjected to the defendant’s allegedly wrongful action.¹⁰⁴ Such cases are unusual; the far more common category involves the uncertain repetition of wrongful conduct to which plaintiffs have been subjected in the past, but which may not recur in the future. The plaintiff in City of Los Angeles v. Lyons, for example, challenged a police chokehold policy to which he had already been subjected, but which he could not be sure he would ever be subjected to again.¹⁰⁵ In both scenarios, courts have often denied standing on grounds that plaintiffs’ claims were too speculative. But we contend that the best solutions in situations like these (to provide sufficient accountability, among other benefits) largely lie outside of conventional standing doctrine—in the law of remedies and timing doctrines of ripeness and mootness, for instance, or in particular institutional arrangements designed to accommodate unique government interests.

A. Undisclosed Exposure

Clapper is the leading example of uncertainty concerning whether a general policy has been applied to the plaintiffs challenging it.¹⁰⁶ The Clapper plaintiffs were attorneys as well as human rights, labor, and media organizations whose work sometimes required them to communicate with individuals located abroad with suspected ties to terrorism. Plaintiffs alleged that some of the individuals with whom they wished to communicate were likely targets of surveillance under the Foreign Intelligence Surveillance Act (FISA).¹⁰⁷ Plaintiffs challenged the FISA on various grounds—primarily on the ground that it allowed authorities to intercept U.S. persons’ communications without a warrant or probable cause.¹⁰⁸ The Supreme Court held that the plaintiffs lacked standing.¹⁰⁹

The Clapper plaintiffs faced so many obstacles that any general lessons must be drawn with care. The plaintiffs challenged surveillance that legally could not target them,¹¹⁰ although they might be incidentally surveilled if communicating with a person abroad who was targeted. But the plaintiffs did not know which non-U.S. persons were actually targeted.¹¹¹ Nor could they be sure whether, if they were party to a surveilled conversation, the government would rely upon § 1881(a) to justify it (as opposed to other legal bases they had not challenged).¹¹² And if the government did rely on § 1881(a), no one could be sure whether the FISA court would actually approve the government’s application and permit the surveillance.¹¹³ The government even argued that it could not be sure whether, if it did target plaintiffs’ conversations and the FISA court approved that surveillance, the technology would actually work and yield intelligible results.¹¹⁴ Of course, underlying all this, the national security interests involved surely influenced the Court’s result.¹¹⁵ At a minimum, those interests foreclosed the most obvious response to the case’s pervasive uncertainties—that is, the Court could not simply require the government to divulge whether and under what circumstances it had surveilled persons with whom the plaintiffs had communicated.

It is hard to say exactly where Clapper left the bar for plaintiffs who might be uncertain whether they were subject to a challenged law or policy in other circumstances. In subsequent surveillance cases, plaintiffs’ standing has turned on their ability to plead and support specific allegations indicating they are likely to have been surveilled; most, but not all, plaintiffs have failed to meet this burden.¹¹⁶ Because national security barriers will often prevent disclosure of critical evidence concerning whether plaintiffs have been subjected to allegedly unlawful government actions,¹¹⁷ the primary checks on secret government actions will likely come through the political process, expansion of checks internal to the FISA program, or criminal proceedings where the government actually seeks to use evidence acquired by surveillance.¹¹⁸

Clapper has been widely cited as “the leading case on claims of standing based on risk of future injury.”¹¹⁹ We contend, however, that the specific holding in Clapper should have little impact outside the rather special context of secret government surveillance. Ordinarily, plaintiffs challenging a general government policy know whether they have been subjected to that policy—or at least they ought to be able to find out through discovery requests early in the lawsuit. Secret surveillance is trickier, of course, because revealing that a party is subject to surveillance will generally cause the surveillance to fail or reveal the government’s methods to other targets.¹²⁰ There may be other situations in which government interests in secrecy or confidentiality foreclose certainty about whether plaintiffs are subject to a challenged law or policy,¹²¹ but we are not aware of many.¹²²

Whether or not a plaintiff is subject to the law they challenge is foundational to standing. A plaintiff ordinarily “has standing to seek redress for injuries done to him but may not seek redress for injuries done to others.”¹²³ This principle is “a rough attempt to put the decision as to whether review will be sought in the hands of those who have a direct stake in the outcome.”¹²⁴ The Court in Clapper enforced this basic requirement with considerable rigor. It is much harder, however, to justify applying Clapper’s rule to situations in which the plaintiff has already been subject to the challenged action in the past or is quite likely to be subject to it in the future and the question involves the probability of harm.

B. Uncertain Repetition of Prior Exposure

A more common scenario involves challenges to executive action based on past incidents that may or may not recur in the future. Plaintiffs in this scenario typically seek to enjoin officers’ future behavior but struggle to show that recurrences are likely to affect them in particular. As Professor Fallon notes, these cases often involve broad allegations of racially tinged police misconduct, thus implicating “questions of enormous practical and political significance” that concern “[t]he scope of judicial oversight of institutional behavior.”¹²⁵

The leading case is City of Los Angeles v. Lyons.¹²⁶ Adolph Lyons alleged that police officers stopped him for a traffic infraction and, without provocation, placed him in a chokehold that rendered him unconscious and damaged his larynx.¹²⁷ Lyons claimed damages based on that encounter, but he also sought injunctive and declaratory relief against an alleged city policy of “regularly and routinely apply[ing] these choke holds.”¹²⁸ Alleging that “numerous persons” had been injured as a result of this policy, Lyons claimed that he “justifiably fear[ed] that any contact he has with Los Angeles Police officers may result in his being choked and strangled to death without provocation, justification or other legal excuse.”¹²⁹ Lyons thus sought a declaration that the chokeholds were unconstitutional and an injunction against their use. The Supreme Court, however, held that he lacked standing to seek the injunction. “Absent a sufficient likelihood that he will again be wronged in a similar way,” the Court said, “Lyons is no more entitled to an injunction than any other citizen of Los Angeles.”¹³⁰

Lyons resonates with current controversies about police tactics and misconduct, and its holding parallels other significant decisions rejecting standing to challenge allegedly racist administration of a local judicial system.¹³¹ It is an uncertain exposure case, even though Mr. Lyons alleged that his mistreatment occurred pursuant to a general policy of the LAPD,¹³² because it remained hard to know which persons would actually become subject to the policy in the future.¹³³ Courts have found standing particularly problematic when, as in Lyons, future exposure to the unlawful government policy may turn on conduct by the plaintiff that is itself unlawful.¹³⁴

The most straightforward way to challenge policies like the LAPD’s is to seek damages based on a past encounter with the police. Mr. Lyons had already been exposed to the chokehold policy; he had a live damages claim and unquestioned standing to bring it.¹³⁵ Success on such a claim would yield not only compensation but an adjudication that the chokehold was illegal.¹³⁶ That adjudication would be res judicata in any future litigation with the City; depending on the scope of the decision, it might encourage a change in policy. Commentary has likely discounted the value of a damages judgment on the assumption that qualified immunity would prevent success.¹³⁷ But if Lyons could prove a systemic policy of chokeholds, qualified immunity would not bar relief against the City.¹³⁸ To the extent that civil rights actions are often brought by victims of past abuse, damages claims may provide a valuable means of adjudicating the legality of police practices.¹³⁹

The central question in Lyons and similar cases, however, is whether plaintiffs have standing to seek prospective relief establishing that the defendant’s actions are illegal and enjoining similar acts in the future. The circuits have generally required plaintiffs to show that they are more likely than the general public to be subjected to the challenged government action in the future.¹⁴⁰ This pragmatic standard serves the intuition to seek out the best available plaintiff, but the Court has also made clear that that the lack of a better plaintiff will not always guarantee standing.¹⁴¹ More fundamentally, the circuits’ rule leaves difficult questions not only as to how likely a future encounter must be but also as to how a court can assess that likelihood accurately. Article III standing doctrine, we contend, is too categorical an instrument to accommodate the nuances that pervade such cases.

We suggest that when plaintiffs have already been subject to the government action they wish to challenge—and have a live damages claim—that should satisfy Article III.¹⁴² Even if a plaintiff’s prior encounter does not give rise to compensable damages, they should at least receive nominal damages that suffice for constitutional purposes.¹⁴³ There is, in this situation, a “case or controversy” for purposes of Article III. The problems that arise in such cases are rather ones of timing and remedy: Does the cessation of the defendant’s action render a claim for injunctive relief moot? Is a future repetition of the action insufficiently certain or imminent to make a claim for declaratory or injunctive relief ripe? Can the plaintiff show the irreparable harm necessary to support an injunction? The law of remedies and the prudential aspects of mootness and ripeness are more flexible instruments than Article III’s jurisdictional standing requirements. They can thus better accommodate the disparate interests at stake in cases of sporadic unlawful actions by government officers.

Start with remedies: The likelihood and severity of future violations of a plaintiff’s rights are the bread and butter of remedial inquiries as to the appropriateness of injunctive relief. Arguably, once a past encounter between the parties creates a live controversy over damages, whether the plaintiff is entitled to other relief is purely a remedial question. And the law of remedies furnishes a range of options that can be calibrated to the circumstances of particular cases. As Lyons suggests, only extraordinarily compelling circumstances might justify an intrusive structural injunction mandating federal judicial supervision of state and local institutions.¹⁴⁴ A prohibitory injunction—for example, “No chokeholds absent a clear threat to police officers”—would be less intrusive and perhaps require less imminence or less severe harm, although concerns about judicial second-guessing would remain.

Likewise, if a plaintiff can show injury from a past encounter, a declaratory judgment concerning the illegality of the defendant’s past conduct should be broadly available. After all, the past encounter surely satisfies the only statutory requirement—”a case of actual controversy within [the court’s] jurisdiction.”¹⁴⁵ Such a binding declaration may be valuable to a plaintiff if unlawful conduct recurs, both for establishing a violation of clearly established law and as a basis for a future injunction. And of course, such a declaration could be written narrowly to address only a particular fact pattern, if a more general ruling about legality was inadvisable. The important point is simply that a remedial frame presents courts with a range of options rather than an all-or-nothing judgment on standing.

The barrier to treating sporadic government legal violations as primarily a remedial problem is the “remedial standing” rule attributed to Lyons itself. Subsequent decisions have cited Lyons for the proposition that “a plaintiff must demonstrate standing separately for each form of relief sought”¹⁴⁶—language that might plausibly mean either of two different things. First, it might mean that a plaintiff who seeks multiple forms of relief—say, damages and an injunction—must establish standing separately for each of them and might well be found to have standing with respect to one and lack it for the other. Second, it might mean that the requirements for standing differ depending upon the remedy sought—for example, some sorts of injuries might support standing to seek an injunction, but not damages. But one might accept this latter principle and still say that once a plaintiff has established standing to seek one form of relief, that makes a case or controversy, and the availability of additional relief is simply a question of remedies. The Supreme Court has emphasized the second principle as recently as TransUnion, holding that a risk of future injury could establish standing to seek injunctive relief but did not suffice in a case seeking only damages.¹⁴⁷ It has never, to our knowledge, applied the first principle to hold that a plaintiff seeking multiple remedies has standing to seek some remedies but not others, although some lower courts seem to have done so.¹⁴⁸ We contend that the second principle is a valuable insight, but the first misreads Lyons and creates inconsistencies with other relevant doctrines.

To begin, Justice White’s majority opinion in Lyons articulated no remedial standing rule whatever. But it could not support the first reading of that rule, other than in dictum. Because Mr. Lyons’s damages claim had been severed from his claim for injunctive relief—and only the latter appealed—the Court had only one form of relief before it and did not consider whether Lyons could have grounded standing in the claim of damages for past unlawful conduct.¹⁴⁹ It would be strange not to permit him to do so. Once a plaintiff has standing to bring one claim for relief, there is a case or controversy permitting the Court to resolve his legal claim. A request for an additional remedy is not a distinct substantive claim over which a court might lack jurisdiction, and it makes more sense to treat the availability of another form of relief as strictly a question of remedy.

At a minimum, the remedial standing doctrine should be considered prudential in nature, rather than constitutional, because it goes to which claims a party can make in litigation, not to the court’s ability to hear the dispute at all.¹⁵⁰ Consider a case in which a party with a live damages claim against the local police moves permanently out of the jurisdiction, so that there is no likelihood of a future encounter supporting his claim for injunctive relief.¹⁵¹ That case comes within Article III because the plaintiff has an injury in fact from his prior encounter with the police. But the argument for injunctive relief would rest on the rights of other persons who might be injured by police misconduct in the future, and it would properly run afoul of the general rule disfavoring third-party standing.¹⁵² That rule is a prudential one, and courts may set it aside for countervailing prudential reasons.¹⁵³

Justiciability’s timing doctrines, ripeness and mootness, reflect this same prudential flexibility.¹⁵⁴ Scholars have debated whether dismissal in a case like Lyons should rest on standing, ripeness, or mootness.¹⁵⁵ When a plaintiff clearly has been or is being subjected to the defendant’s challenged action or policy, remaining temporal uncertainties generally are—and should be—resolved under the timing doctrines. As Professor Fallon pointed out in his article on Lyons, “the issue arising from the passage of time after an acknowledged injury, sufficient at some moment to confer standing, easily could have been analyzed as one of mootness instead of standing.”¹⁵⁶

Three settled aspects of mootness doctrine are relevant. First, once a plaintiff has established a basis for being in federal court, “a case ‘becomes moot only when it is impossible for a court to grant any effectual relief whatever to the prevailing party’ ”; “[a]s long as the parties have a concrete interest, however small, in the outcome of the litigation, the case is not moot.”¹⁵⁷ These standards are plainly easier to meet than the standard for establishing standing in the first instance. In a case like Lyons, they would ask whether the plaintiff can make a case for any meaningful form of prospective relief. Second, where plaintiffs were subjected to unlawful action in the past, mootness doctrine does not require them to establish standing afresh to forestall a potential recurrence. Rather, the defendant must shoulder the “ ‘heavy burden of persua[ding]’ the court that the challenged conduct cannot reasonably be expected to” recur.¹⁵⁸ Finally, although recurrences must affect the same plaintiff, the standard is simply whether “there [is] a reasonable expectation that the same complaining party [will] be subjected to the same action again.”¹⁵⁹ These principles illustrate that, simply because claims arising out of a past encounter with the defendant may have become moot, the plaintiff need not start back at square one to establish standing to enjoin a recurrence of the defendant’s conduct.

Cases like Lyons also implicate ripeness, because plaintiffs in these cases ask a court to consider future events. Ripeness doctrine helpfully shifts the inquiry away from pure (and intractable) questions of probability to more manageable questions about the court’s ability to decide the case now and the impact on the parties if it chooses to wait. If Mr. Lyons had sought pre-enforcement review of LAPD’s chokehold policy, ripeness doctrine would have required him to establish that the issues were fit for judicial review and that he would experience hardship if forced to litigate after the policy had been applied to him in the future.¹⁶⁰ The fact that he had already been subjected to the policy would both tee up the issues in a concrete factual setting and allow him to argue that he should not be exposed to the risk of further physical injury. Conversely, if future occurrences were likely to be quite different from the past incident, then a court might appropriately hold claims for prospective relief to be premature.

These prudential rules should govern where, unlike in Lyons, a live damages claim is still part of the case. But our fundamental point is that the probability problem in cases like Lyons cannot be solved by trying to establish a threshold likelihood of injury. Standing doctrine should not duplicate the work already done by remedial law and temporal doctrines like ripeness or mootness. We take up the latter point again below in Part IV, but first we consider the question whether careful definition of injury in the first place can reduce the scope of the problem.

III. Uncertain Harm and Cognizable Injury

What if the plaintiff is subject to the challenged action but not certain to be harmed? Canonical statements of the injury-in-fact requirement have long said that the injury must be “actual or imminent, not conjectural or hypothetical,”¹⁶¹ or “certainly impending.”¹⁶² Courts have employed this language—which speaks to both certainty and temporal proximity¹⁶³—as a limit when the plaintiff grounds injury in a future harm. But, as Professor Cox has noted, “what is meant by ‘imminent’ or ‘certainly impending’ remains ambiguous, poorly defined, and inconsistently applied.”¹⁶⁴ No one seems to know how certain, or how imminent, an injury has to be. And what is the relationship between the imminence requirement, which seems like a mini-ripeness doctrine within the standing criteria, and the ripeness doctrine itself?

A. Probability and the Definition of Injury

To evaluate the imminence or probability of injury, one must know what kind of injury counts for purposes of Article III. Consider, for example, the range of injuries at issue in TransUnion. The named plaintiff, Sergio Ramirez, suffered a good old-fashioned tangible injury when he was denied the opportunity to buy a car based on the erroneous OFAC alert in his credit report.¹⁶⁵ In Ramirez’s case, that injury is certain—it had already occurred when he filed suit. No such tangible injury had yet happened to the larger group of 1,852 class members. But because TransUnion had disseminated erroneous information about them to third-party businesses, that group stood at risk of similar harm in the future.¹⁶⁶ This depended, however, upon the reaction of those businesses to the misinformation—it depended, in other words, on the behavior of third parties not before the court. The 6,332 remaining class members bore a similar risk, because their credit files likewise contained a false OFAC alert. But that risk was less imminent (and also somewhat less likely) because no OFAC alert had yet been disseminated to third-party businesses during the class period.¹⁶⁷

The TransUnion majority saw a tangible injury like Ramirez’s as sufficient but not necessary for injury in fact. Rather, they accepted the plaintiffs’ argument that “publication to a third party of a credit report bearing a misleading OFAC alert injures the subject of the report” in a way closely analogous to the reputational harm of defamation.¹⁶⁸ That injury sufficed for standing, and it was just as certain as Ramirez’s injury, having already occurred. For the remaining class members, however, this reputational injury remained probabilistic. These plaintiffs argued that, because a similar misleading alert might well be disseminated to third parties in the future, “the existence of misleading OFAC alerts in their internal credit files exposed them to a material risk that the information would be disseminated in the future to third parties and thereby cause them harm.”¹⁶⁹ The Court held that such a risk is not, by itself, a sufficient injury for purposes of Article III standing to seek damages.¹⁷⁰

Injuries can be defined in different ways, even on the same basic facts, and the choice of definition can significantly affect the probability of the respective injuries. But some capacious forms of injury tend to obviate the probability problem altogether. The 6,332 residual plaintiffs did arguably have an injury that had already occurred: the violation of their legal right under the FCRA not to have false or misleading information included in their files. The dissenters argued that such a purely legal injury is sufficient, as long as the injury is to private, rather than public, rights.¹⁷¹ The majority, by contrast, insisted that “under Article III, an injury in law is not an injury in fact.”¹⁷²

Another possibility is that risk of harm should be deemed a cognizable injury in fact. In TransUnion, all class members faced a risk that they would experience tangible harm like Ramirez’s. Defining risk as injury avoids the need to describe the injury itself as probabilistic; we know for sure, in TransUnion, that the risk exists at the present moment.¹⁷³ Similarly, the class members might have argued—although apparently they did not—that TransUnion’s FCRA violation caused them present distress or forced them to incur present expenses to guard against future reputational damage. Recognizing these sorts of present injuries would likewise dissolve any doubts about the probability of future injury.

Much discussion of these various classes of injury has asked whether risk, or costly precautions, or anxiety simply “is” or “is not” a cognizable injury for Article III purposes. We would resist that approach on the principle that Article III is not a font of tort law¹⁷⁴ (or contract or property law either)—that is, it does not purport to define the interests that give rise to cognizable injuries. Article III’s text alone offers no guidance as to which interests are in or out. The Court has instead looked to tradition, considering whether an alleged harm has a “close relationship” to injuries historically “recognized as providing a basis for a lawsuit in American courts.”¹⁷⁵ Consistent with this statement, much of the law structuring the federal judicial system looks to historical practice and the practice of the state courts, while leaving a considerable say to Congress.¹⁷⁶ The Court’s standing jurisprudence establishes a kind of reflective equilibrium between the injuries generally recognized in federal and state positive law, including the English common law background, and the more specific values of Article III standing jurisprudence, which usually sound in separation of powers.

TransUnion thus embraced two principles for evaluating possible injuries as a basis for Article III standing that push in different directions. First, the injuries that count for standing will often be a function of the underlying substantive law.¹⁷⁷ “Congress’s views may be ‘instructive’ ” in “determining whether a harm is sufficiently concrete to qualify as an injury in fact,” and “[c]ourts must afford due respect” to legislative choices in this area.¹⁷⁸ The Court looked to the common law to see if a plaintiff’s injury “bears a ‘close relationship’ to a harm traditionally recognized as providing a basis for a lawsuit in American courts.”¹⁷⁹ Second, the Court insisted that Article III imposes a floor on interests that can count for standing. Congress “may not simply enact an injury into existence, using its lawmaking power to transform something that is not remotely harmful into something that is.”¹⁸⁰ Analysis of particular classes of injury must take its cues from the underlying substantive law yet appreciate that Article III imposes an independent constraint.¹⁸¹

The case law reveals three categories of interests. The first consists of interests that are clearly in, such as property and liberty interests and other interests traditionally protected by the common law. When plaintiffs can show physical injury or financial loss occasioned by a defendant’s conduct, courts do not usually look to see if there is some further legal recognition of the plaintiffs’ harm before concluding that they have injury in fact.¹⁸² The second category encompasses interests that are clearly out—that is, that cannot establish injury in fact even if Congress enacted a statute purporting to protect them. Interests of this kind typically involve some sort of generalized grievance, such as “harm to . . . every citizen’s interest in proper application of the Constitution and laws.”¹⁸³ Likewise, the Court has “consistently held” that taxpayers’ interest in the use of tax monies for lawful purposes “is too generalized and attenuated to support Article III standing.”¹⁸⁴

The most interesting category consists of interests that are not obviously cognizable but which positive law may recognize as actionable and thus cognizable under Article III.¹⁸⁵ One example is the FCRA’s transformation of an interest in reputation. In TransUnion, the credit-reporting company argued that the erroneous information included in the plaintiffs’ credit reports was merely misleading, while the common law of defamation required actual falsity.¹⁸⁶ The Court responded that although a plaintiff’s injury must bear “a ‘close relationship’ to a harm traditionally recognized as providing a basis for a lawsuit in American courts, we do not require an exact duplicate.”¹⁸⁷ Within certain bounds, in other words, Congress may by statute expand the set of actionable harms beyond claims that the common law would have recognized as sufficient for liability.¹⁸⁸ The Court thus concluded that “the harm from a misleading statement of this kind bears a sufficiently close relationship to the harm from a false and defamatory statement.”¹⁸⁹ In contrast, for those plaintiffs whose credit files had not yet been accessed by third parties, there was “no historical or common-law analog where the mere existence of inaccurate information, absent dissemination, amounts to concrete injury.”¹⁹⁰

This approach is similar to what Tom Merrill has called a “patterning definition” in the context of property interests protected under the Due Process Clause.¹⁹¹ That clause generally does not itself create property interests, but it does set outer bounds. Some interests must be treated as property for due process purposes, even if state law does not treat them as such, while other interests cannot be even if they are recognized as such by other positive law.¹⁹² Likewise, Article III allows legislatures and common law courts considerable freedom to determine whether invasion of particular interests will qualify as injury in fact (category 3), but federal constitutional criteria both treat some familiar interests as conclusively sufficient (category 1), on the one hand, and limit the interests that may be recognized (category 2), on the other.¹⁹³

Critics have argued that TransUnion’s approach “significantly changes the law and places in doubt the ability to sue to enforce countless federal laws,”¹⁹⁴ but this charge seems overstated. TransUnion’s references to the common law are not new,¹⁹⁵ and whether application of the historical test has changed remains to be seen. To be sure, statutory citizen-suit provisions conferring rights to sue without any showing of an individualized interest will be hard to square with TransUnion, but the validity of that sort of suit has been in doubt for at least 30 years.¹⁹⁶ Justice Kavanaugh’s opinion in TransUnion made clear that, in looking for historical analogies to support a new statutory cause of action, “we do not require an exact duplicate.”¹⁹⁷ The Court’s willingness to recognize dissemination of erroneous information as injury without any showing of tangible harm does not strike us as all that restrictive.¹⁹⁸

On the other hand, some courts have interpreted TransUnion as requiring a pretty close match between the harms addressed by statutory causes of action and harms recognized by common law torts (such as for defamation or invasion of privacy).¹⁹⁹ The closer the “harm-to-harm comparison” that courts demand,²⁰⁰ the smaller the third category of legislative flexibility becomes.²⁰¹ Divergent approaches to this question among the circuit courts of appeal have arguably ripened into a circuit split,²⁰² and the proliferation of holdings that Article III forecloses particular claims under the Fair Debt Collection Practices Act (FDCPA) may well require Supreme Court review sooner rather than later.²⁰³

The broader question of how broadly Article III permits legislatures to recognize new categories of harm is beyond the scope of this Article. It does seem clear that, after TransUnion, considerable room remains for argument about whether particular forms of injury can suffice for Article III injury in fact. The next two sections play that analysis out for the most frequently invoked categories of injury in probabilistic standing cases.

B. Legal Injuries, Risk, and Remedies

Many probabilistic standing cases involve a present legal injury that may or may not result in actual harm sometime in the future. Notwithstanding the majority’s insistence in TransUnion that purely legal injury is not sufficient under Article III, the Court’s modern standing jurisprudence has waffled back and forth.²⁰⁴ It is not easy to reconcile TransUnion, for example, with the Court’s decision the same term in Uzuegbunam v. Preczewski. That case—an 8–1 decision written by Justice Thomas—adopted the common law rule “allowing nominal damages for a violation of any legal right” and held that nominal damages satisfy Article III.²⁰⁵ Does that mean that all of the TransUnion plaintiffs could have had standing if the FCRA had authorized them to recover one dollar for violation of their legal rights?²⁰⁶ Uzuegbunam suggests that, in some circumstances, Congress could authorize damages for a purely legal violation, at least those involving constitutional or traditional legal interests.

Moreover, neither TransUnion nor Spokeo purported to disturb a variety of well-established causes of action that do not require the plaintiff to establish any actual injury to prevail. One example is unjust enrichment. Although “the paradigm case of unjust enrichment is one in which the benefit on one side of the transaction corresponds to an observable loss on the other,” unjust enrichment may also arise when the defendant has obtained a benefit “ ‘in violation of the other’s legally protected rights,’ without the need to show that the claimant has suffered a loss.”²⁰⁷ Plaintiffs may thus seek restitution of a defendant’s gains obtained by commercial bribes or kickbacks, wrongful appropriation of a business opportunity, misuse of confidential information, or other conflicts of interest without showing any consequential damage.²⁰⁸ Likewise, owners of copyrights, trademarks, or trade secrets can recover a defendant’s profits from an infringement even if the plaintiff cannot show losses of her own.²⁰⁹ Some torts, moreover, are actionable without proof of damage to the plaintiff;²¹⁰ in fact, the tort of defamation at the heart of TransUnion is one of them.²¹¹ Finally, as the Court acknowledged in Spokeo, invasions of constitutional rights can suffice for concrete injury without any consequential harm.²¹²

The Court has not clearly articulated a theory of standing that squares these circumstances in which legal injury seems to suffice with its analysis and results in Spokeo and TransUnion. Two possibilities seem plausible. The first draws on TransUnion’s point that standing requirements differ depending upon the remedy that the plaintiff seeks. As we discuss further below, the Court said that plaintiffs may rely on a risk of sufficiently imminent harm to establish injury in fact if they seek a preventive injunction but not in an action for damages.²¹³ That would explain the constitutional rights cases cited in Spokeo, and one could accommodate the unjust enrichment cases by stressing that restitution is a fundamentally different remedy than compensatory damages.²¹⁴ But it is hard to explain why a claim for nominal damages based on the violation of Mr. Uzuegbunam’s legal rights sufficed for standing, while a claim for statutory damages for TransUnion’s violation of FCRA rights was insufficient.²¹⁵

The better explanation is that a violation of someone’s legal rights may involve “an invasion of a legally protected interest that is concrete and particularized,”²¹⁶ even if there are no further consequential damages. Spokeo and TransUnion both acknowledged that intangible injuries may suffice as injury in fact. Just as the Court has accepted violation of a personal constitutional right as a sufficient injury, so too the violation of a property right in a trespass case, or a duty of loyalty owed to the plaintiff in an unjust enrichment case, may amount to “actual” injury even if no further physical or financial consequences flow from it. That was true in TransUnion, where the Court did not require plaintiffs to prove any consequential damages from the publication of incorrect information about them.²¹⁷ Each of these injuries “bears a ‘close relationship’ to a harm traditionally recognized as providing a basis for a lawsuit in American courts.”²¹⁸

But the more important point may be that in each of these situations, the law provides a particular individual with a right to do something, have something, or enjoy a certain sort of security (e.g., from the fear that an agent may have a conflict of interest or from publication of false information), and the denial of these entitlements by a defendant’s unlawful act works an “actual” injury. Although the line will not always be easy to draw, that sort of wrong can reasonably be seen as harmful in a way that the incorrect but undisseminated OFAC alert in the TransUnion plaintiffs’ files was not.²¹⁹ If this is correct, then the key in so-called “legal injury” cases will be to distinguish between invasions of legal interests analogous to individual constitutional rights, trespass, and unjust enrichment and “bare procedural violation[s]” of the sort found wanting in TransUnion.²²⁰ At least with respect to the plaintiffs alleging only such violations, the Court in TransUnion likely saw the suit as one in which Congress had simply offered a bounty for private enforcement of the FCRA’s procedural requirements rather than an effort to protect a real personal interest.²²¹

One might still effectively sweep in all legal violations by treating the risk of future harm as a present concrete injury. The TransUnion plaintiffs tried to establish “actual” injury by asserting that “misleading OFAC alerts in their internal credit files exposed them to a material risk that the information would be disseminated in the future to third parties and thereby cause them harm.”²²² This sort of argument enjoys considerable support in the commentary. Professor Nash points out, for example, that conventions of risk analysis typically calculate the “expected value” of a risk “by multiplying the magnitude of the harm by its probability.”²²³ Nash argues that “[i]f people have suffered a loss with a positive expected value, they have suffered an ‘injury in fact.’ It is unhelpful to say, as courts often have done, that an injury is ‘speculative’ or ‘conjectural’ when it has a positive expected value.”²²⁴

Some lower courts have accepted this sort of reasoning while others have not.²²⁵ The answer seems to turn not only on divergent readings of Spokeo and TransUnion, but also on the plaintiff’s legal theory. A negligence or strict liability theory, for example, generally requires a realized harm;²²⁶ a breach of warranty theory, on the other hand, may be more likely to recognize failure to prevent a future risk as a present harm.²²⁷ Another variable, in state law cases, is different jurisdictions’ decisions on whether to permit liability for exposure to risk under the relevant substantive law.²²⁸

There are good reasons to hesitate before recognizing subjection to risk as an independent injury in fact. One is that this solution to the probability problem is largely semantic because the next question would be how much risk must exist to constitute a cognizable injury in fact. It is hard to see how that question is any less difficult than asking how probable some future harm must be to satisfy the same standard. Professor Nash initially avoids this trap by saying that all positive present value amounts to injury in fact,²²⁹ but then he hops right back into it by introducing a prudential restriction eliminating “de minimis” injuries.²³⁰ How minimal is de minimis? The Supreme Court, after all, has said that even small or nominal injuries are sufficient for Article III.²³¹

The present-value argument also conflates two distinct questions. As Professor Cox observes, standing law always requires a normative judgment about whether a particular injury will be “cognizable,”²³² but considering whether risk of an injury should itself be cognizable requires two such judgments: “one about primary interests, and one about a secondary, derivative interest in not having increased risk of harm to the primary interest.”²³³ She notes that “identity theft can be an injury, while the increased risk of it might not be . . . .”²³⁴ Professor Chris Schroeder similarly observes that even though everyone agrees that harm to human health counts as regulable harm, “modern governmental regulation . . . reflect[s] our wide disagreement over what constitutes a regulable risk.”²³⁵ Reducing risk to merely the “expected value” of any injury that would otherwise be actionable tends to overlook meaningful disagreements about when—and how much—risk ought to suffice.

A second question concerns whether the injury of being subjected to a risk of future harm is sufficiently particularized. Writing for the D.C. Circuit, then-Judge Kavanaugh argued that “the mere increased risk of some event occurring is utterly abstract—not concrete, direct, real, and palpable. . . . [I]ncreased risk falls on a population in an undifferentiated and generalized manner; everyone in the relevant population is hit with the same dose of risk, so there is no particularization.”²³⁶ We are less sure that such injury is undifferentiated; each person’s risk is that they will get cancer, not someone else.²³⁷ The more fundamental problem is that, although we may be confident that the risk will materialize with respect to some members of the relevant population, those members remain “statistical persons rather than identifiable persons.”²³⁸

TransUnion addressed the interest in avoiding risk of harm by distinguishing sharply between damages and injunctive relief. The Court acknowledged that “ ‘risk of real harm’ . . . can sometimes ‘satisfy the requirement of concreteness.’ ”²³⁹ But it insisted that this possibility is limited to “suit[s] for injunctive relief,” stating that “a person exposed to a risk of future harm may pursue forward-looking, injunctive relief to prevent the harm from occurring, at least so long as the risk of harm is sufficiently imminent and substantial.”²⁴⁰ The last phrase suggests that plaintiffs seeking injunctive relief cannot avoid the “imminence” requirement simply by recharacterizing an uncertain future harm as a harm experienced in the present. We argue in Section IV.A that imminence is better handled as a matter of ripeness. In any event, “a plaintiff’s standing to seek injunctive relief does not necessarily mean that the plaintiff has standing to seek retrospective damages.”²⁴¹

TransUnion thus accepted the defendant’s argument “that in a suit for damages, the mere risk of future harm, standing alone, cannot qualify as a concrete harm—at least unless the exposure to the risk of future harm itself causes a separate concrete harm.”²⁴² By “separate” harm, the Court meant emotional distress or some other present injury arising from exposure to risk²⁴³—a possibility that we consider in the next section. But why distinguish between injunctions and damages in the first place? Although these remedies might well address different kinds of harm, one would expect that distinction to be a function of the law of remedies, not Article III standing.

The Court did not fully explain its reasoning on this point, but it offered a suggestive hypothetical example:

Suppose that a woman drives home from work a quarter mile ahead of a reckless driver who is dangerously swerving across lanes. The reckless driver has exposed the woman to a risk of future harm, but the risk does not materialize and the woman makes it home safely. . . . [T]hat would ordinarily be cause for celebration, not a lawsuit. . . . But if the reckless driver crashes into the woman’s car, the situation would be different, and . . . the woman could sue the driver for damages.²⁴⁴

As with the woman who got home safely, the Court stressed that “the 6,332 plaintiffs did not demonstrate that the risk of future harm materialized—that is, that the inaccurate OFAC alerts in their internal TransUnion credit files were ever provided to third parties or caused a denial of credit.”²⁴⁵ This discussion suggests that the distinction between damages and injunctions rests on a more fundamental difference between realized and unrealized harm. Injunctions are frequently available to prevent the realization of harm; if there were a way to predict the bad driver’s reckless behavior in advance, one might well obtain a prohibitory injunction against it. But courts generally award damages only for realized harms.²⁴⁶ This is sufficient reason to doubt that Professor Nash’s expected-value analysis—familiar to investors and risk managers—can translate well to the law of remedies.

Whether the law should recognize risk of future harm as a present injury remains controversial.²⁴⁷ We have considerable sympathy for Professor Cox’s view that Article III does not itself take a position on whether risk should count for injury. The contrary view would certainly put much weight on words like “case,” “controversy,” or “judicial power.” Cox argues, consistent with a general theme of this Article, that the question is not so much whether to recognize risk as an independent injury in fact but rather who should decide that issue.²⁴⁸ In other words, courts should ordinarily defer to the underlying substantive law—whether it comes from a legislature, executive agency, or common law court—in determining whether to treat a present risk of a future injury as injury in fact. If Professor Mank is right that “most environmental and safety risks are probabilistic in nature,”²⁴⁹ for example, then Congress could build that recognition into the relevant statutes (and leave it out of statutes involving more traditional harms).

Squaring this position with TransUnion depends on the size of our third category of harms, in which legislators exercise some discretion to authorize suits by parties suffering harms that are analogous to traditionally actionable wrongs.²⁵⁰ TransUnion seems to have read the effort to seek FCRA damages for errors in undisseminated credit reports as a bounty for private enforcement of an essentially public procedural obligation, not a meaningful personal interest. But that decision need not be read to foreclose Congress from elevating exposure to risk of actual private harms to a legally cognizable injury. TransUnion did not attempt to explain why Article III forecloses recognition of risk as cognizable injury. State law sometimes permits damages for imposing a risk of future harm,²⁵¹ and it would be odd for a federal court sitting in diversity to dismiss such a case for lack of Article III standing. And the Court’s willingness to hear claims for prospective relief when the only present injury is the risk of future harm strongly suggests that such risk can sustain an Article III lawsuit.

Although TransUnion has become a central focus of standing doctrine in the lower courts, we contend that it is being read more expansively than necessary. Dean Chemerinsky may be correct that it “has the potential to dramatically restrict standing to sue in federal courts to enforce federal statutes,”²⁵² but that reading is not inevitable. In suits for prospective relief—the heart of public law litigation²⁵³—TransUnion has little bite by its own terms.²⁵⁴ And although federal statutes should generally not be read to permit recovery of damages based on exposure to risk of future harm, the Court has not categorically foreclosed that possibility. Even read for all it is worth, TransUnion did not bar a legislature from providing for statutory damages based on the likely present harms arising from risks.

C. Reduced Value, Costly Precautions, and Anxiety

Risks of future harm impinge on present behavior and well-being. Rational persons value property based in part on what is likely to happen to it in the future; they avoid actions they would normally take; they invest in other precautions against future harm; and they worry about future risks—sometimes to the point of severe emotional distress. Each of these phenomena is at least sometimes treated as cognizable harm in substantive causes of action, and each therefore offers a way for plaintiffs to plead around probabilistic standing problems. Much debate among the lower courts in probabilistic standing cases concerns these collateral consequences of risk, and the Supreme Court has sent mixed signals. As with the debate about risk itself, there is a temptation to ask whether diminished value, precautionary expenditure, and psychological harm simply are or are not cognizable under constitutional standing principles, but we contend that this is not a very fruitful inquiry.

This Section analyzes how these types of present harms fit into our three categories of cognizable and noncognizable interests. It will help to begin with cases in which the plaintiff sues under a common law cause of action or a generic statutory one—such as the Administrative Procedure Act or 42 U.S.C. § 1983—that does not specifically make the injury in question cognizable. Our Category 1 interests are those sorts of interests that familiarly form the basis of such lawsuits.

A reduction in the value of property, resulting from the defendant’s conduct, seems to fit comfortably in this category of presumptively cognizable harm. In Cole v. General Motors Corp.,²⁵⁵ for example, the plaintiffs represented a class of persons who had purchased cars from GM which, they alleged, had defective air bag systems. Although none of the class members had actually been in an accident in which the defect had manifested and caused them injury, they claimed that GM had promoted the air bag systems as a valuable safety feature, failed to deliver that feature, and thus reduced the value of the automobiles they had purchased. Their legal theory focused on breach of express and implied warranties.²⁵⁶ The court of appeals rejected GM’s argument that the plaintiffs lacked standing because they had not yet experienced any injury in fact; it was enough, the court said, that “[p]laintiffs seek recovery for their actual economic harm (e.g., overpayment, loss in value, or loss of usefulness) emanating from the loss of their benefit of the bargain.”²⁵⁷

The court in Cole went out of its way to note that “[w]hether recovery for such a claim is permitted under governing law is a separate question; it is sufficient for standing purposes that the plaintiffs seek recovery for an economic harm that they allege they have suffered.”²⁵⁸ That statement seems to contradict our notion that cognizability of an injury for standing purposes depends chiefly on whether the underlying law recognizes that injury. The critical point, however, is that diminished value is a sort of harm commonly and traditionally recognized in American law—even though jurisdictions differ on whether plaintiffs can recover on breach of warranty or tort claims when a product defect has not manifested in a failure causing injury to the plaintiff.²⁵⁹ Our first category of injury thus presumptively suffices for injury in fact so long as it is generally recoverable in American law, whether or not the plaintiff will be able to recover in particular circumstances. That is probably why most of the cases refusing to recognize decreased-value injury in no-manifest-injury cases are not standing cases, but cases decided on the merits.²⁶⁰

On a first cut, precautionary expenses incurred to mitigate risks arising from unlawful action by the defendant fit readily within our first category of presumptively cognizable injury. A personal injury plaintiff’s medical expenses, or expenses incurred to repair property damage, are a mainstay of private litigation. Plaintiffs may also incur such costs in response to a risk of injury. “In recent years,” one court noted, “tort plaintiffs have increasingly sought, and have regularly been awarded, medical monitoring costs in both toxic tort and product liability cases.”²⁶¹ In data breach cases, plaintiffs often seek to recover the cost of credit monitoring or changing service providers.²⁶² Courts sometimes allow standing to recover for such precautionary and mitigation costs, but the cases are mixed.

Here, too, courts have tended to over-rely on Clapper.²⁶³ The Clapper plaintiffs tried to establish standing not only by citing the threat that their conversations would be spied upon but also by alleging that that threat had obliged them to take burdensome and sometimes costly measures to protect their conversations’ confidentiality.²⁶⁴ The Supreme Court, however, concluded that “[b]ecause [plaintiffs] do not face a threat of certainly impending interception . . . the costs that they have incurred to avoid surveillance are simply the product of their fear of surveillance, and . . . such a fear is insufficient to create standing.”²⁶⁵ The critical factor was that the plaintiffs could not establish that they were subject to the government action they challenged, and the cost of precautions incurred just in case they were so subject could not supply the necessary injury. “If the law were otherwise,” the Court explained, “an enterprising plaintiff would be able to secure a lower standard for Article III standing simply by making an expenditure based on a nonparanoid fear.”²⁶⁶ The situation of a mere “nonparanoid fear” is quite different from one involving a known violation of one’s legal rights.

Importantly, the Court did rely on costly precautions to establish injury in Monsanto v. Geertson Seed Farms.²⁶⁷ The plaintiffs there were non-GMO alfalfa farmers who challenged a federal agency’s decision to deregulate Roundup Ready Alfalfa (RRA), a genetically modified form of alfalfa designed to tolerate a popular herbicide.²⁶⁸ In holding that the non-GMO farmers had standing, the district court found that they had “ ‘established a reasonable probability’ that their organic and conventional alfalfa crops will be infected with the engineered gene’ if RRA is completely deregulated.”²⁶⁹ Because of that risk, the Court emphasized, plaintiffs had taken “certain measures to minimize the likelihood of potential contamination.”²⁷⁰ The Court stressed that those expenses injured the plaintiffs “even if their crops are not actually infected with the Roundup Ready gene” and were “sufficiently concrete to satisfy the injury-in-fact prong of the constitutional standing analysis.”²⁷¹

These decisions hardly provide a clear rule for when costly precautions will suffice to establish injury in fact. As already discussed, plaintiffs who cannot establish that the defendant has acted upon them at all—as in Clapper—cannot ordinarily establish standing. Monsanto’s facts, on the other hand, presented an unusually high degree of certainty that the plaintiffs would be affected by the challenged approval of RRA.²⁷² The central dilemma may be best expressed in cases like Tsao v. Captiva MVP Restaurant Partners, LLC,²⁷³ decided by the Eleventh Circuit in 2021. That case held that costs of precautions could serve as injury only when there is a “substantial risk” of the underlying harm—the same degree of probable future harm needed to make the underlying future harm itself cognizable for standing purposes.²⁷⁴ On this approach, costly precautions could never serve as an independent basis for standing.²⁷⁵ Tsao thus starkly poses the question of whether costly precautions should ever lower the bar for standing when the future harm itself remains insufficiently “imminent” to support standing on its own. Significantly, other lower courts more receptive to costly precautions as injury have found the underlying future harm itself to be sufficiently imminent to satisfy Clapper.²⁷⁶ Such decisions are not necessarily inconsistent with Tsao and similar cases.

Courts hesitate to base standing on costly precautions alone because those precautions are within the plaintiff’s control and “monetary expenditures are viewed as too easy to manufacture.”²⁷⁷ Precautionary costs thus need some sort of limiting principle to ensure that they are reasonably undertaken, rather than incurred simply to support litigation. If this limiting principle is to be a function of probability—that is, if precautions are reasonable according to the likelihood of the harm they guard against—then it is hard to see why the requisite quantum of probability (whatever it is) for taking reasonable precautions should not be the same as that needed to support judicial action based on the underlying risk. After all, an injunction is a precaution against a risk of future harm.

We would minimize the extent to which courts must assess the various probabilities in individual cases. And we would evaluate the risk of the underlying future harm differently from the costly precautions that plaintiffs sometimes take. Our framework would rest on three principles: First, Clapper stands for the proposition that if a plaintiff cannot establish (under the respective standards at the pleading or summary judgment stage) that they have even been subjected to the defendant’s allegedly unlawful action, then costs incurred in efforts to mitigate that action’s effects will not create injury in fact, even if they seem reasonable in light of the uncertainty. But as we suggested earlier, these circumstances should be quite rare.²⁷⁸ Most cases will be governed by a second principle, which is that costly precautions will count as injury in fact where they are consistent with the underlying law. We would rely, for example, on tort rules specific to particular classes of cases to establish when harm from a toxic exposure or data breach is likely to warrant precautionary measures.²⁷⁹ In those classes of cases, Article III should pose no additional barrier. Third, even if costly precautions suffice, prudential ripeness limitations might nonetheless bar review if the future harm that is the ultimate subject of the litigation were so amorphous or distant as to render the legal issues in question unfit for review.

Critically, our framework would judge whether precautionary costs count as injury in fact not by assessing the likelihood of the future risk in individual cases but by looking to whether the underlying law (or common practice) generally acknowledges precautions as an appropriate response to a category of risk. In toxic torts, medical monitoring is becoming a common remedy; likewise, credit monitoring is increasingly prevalent in data breach cases.²⁸⁰ In some cases, the risk may be sufficiently remote that no recovery of precautionary costs is appropriate. But we would leave that for the merits or remedial phase, rather than asking judges to make these particularistic probability judgments up front as part of the standing analysis. It should be enough that the complaint states a plausible claim of injury of a type that is broadly recognized by the underlying body of substantive law. By definition, our approach would allow Congress to create causes of action to recover precautionary costs.²⁸¹

We can imagine some hard cases under this rubric, particularly those that do not fall into a well-established “category” of substantive law. If standing in Massachusetts v. EPA²⁸² had depended on costly precautions taken by private landowners—building a seawall, for instance, to keep out rising seas caused by climate change—it might be difficult to assess the reasonableness of such precautions considering the unpredictable timing, magnitude, and precise location and character of the impending threat. Two points give us comfort, however: First, courts need not assess the probability of the actual risk but simply whether it is sufficiently probable, in light of both its likelihood of occurring and its magnitude, to render precautionary measures reasonable. Second, because the magnitude of injury is not important under Article III,²⁸³ courts need not decide whether each particular precaution is reasonable under the circumstances but only whether some precautions are.

What about anxiety or emotional distress as a basis for injury in fact? TransUnion specifically reserved judgment on this issue, and standing literature has addressed it as a general question under Article III.²⁸⁴ The Seventh Circuit’s 2022 decision in Pierre v. Midland Credit Management, Inc.²⁸⁵ provides a good example of the problem. There, a creditor attempted to persuade someone to pay a debt even though the statute of limitations would have barred legal recovery on the debt, thereby allegedly violating the Fair Debt Collection Practices Act (FDCPA). Although the debtor never actually paid the debt in response to the creditor’s efforts, she brought a class action suit under the FDCPA²⁸⁶ and obtained a jury award of $350,000. A divided panel rejected the plaintiff’s argument that the worry and confusion she experienced because of the creditor’s actions sufficed for standing.²⁸⁷

On the one hand, it seems obvious that emotional distress or anxiety ought to satisfy injury in fact in at least some circumstances. Some emotional distress claims have long been actionable at common law (most notably, claims for intentional infliction of emotional distress).²⁸⁸ Other well-established claims at common law, such as claims relating to invasion of privacy and harm to reputation, are based in part on the emotional injury that such conduct tends to cause.²⁸⁹ On the other hand, the common law has long been cautious about emotional distress claims. Claims for negligent infliction of emotional distress, for example, are typically only actionable in connection with a physical injury.²⁹⁰ Moreover, recognizing anxiety or emotional distress injuries offers a ready end-run around any limits on recognizing legal or future risk-based injuries. And some forms of anxiety may be so widespread as to offend the principle barring generalized grievances.

We would again leave this largely to the underlying substantive law. When a plaintiff alleges a claim under a federal statute that the Supreme Court has held does not permit damages for emotional distress,²⁹¹ for example, emotional distress alone should not suffice for injury in fact. A tort plaintiff alleging intentional infliction of emotional distress, on the other hand, should generally not encounter any standing problem. The question would not be whether this plaintiff’s emotional injury was sufficiently serious or certain but whether the law governing the plaintiff’s claim generally recognizes emotional injury as a harm or part of a larger category of circumstances that includes the plaintiff.²⁹² Legislatures, moreover, would ordinarily be able to satisfy Article III by rendering emotional injury or anxiety cognizable by statute.

Anxiety and emotional distress also provide a good illustration of our second category: cases in which Article III excludes a particular injury from recognition, even if a legislature attempts to make it actionable. In some circumstances, almost anyone may feel anxiety and emotional distress arising from a defendant’s violation of the law.²⁹³ For example, we are both professors of public law, with a considerable intellectual (and even emotional) investment in the rule of law and compliance with constitutional norms in which we are interested. If the President acts unconstitutionally, particularly in a sphere about which we write and teach, that may cause us far more distress and anxiety than if, say, our neighbor lets his dried leaves blow onto our property.²⁹⁴ But one bedrock principle of standing jurisprudence is that “an injury amounting only to the alleged violation of a right to have the Government act in accordance with law [is] not judicially cognizable.”²⁹⁵ So if Congress enacted the Law Professors’ Peace of Mind Act, empowering any academic who plausibly alleged distress and anxiety to challenge illegal action by a government official, the Court would surely strike that down. The generalized grievance rule thus sets an outer bound on the ability of legislatures or courts to expand standing by recognizing rights to recover for emotional distress or anxiety.

* * *

Many probabilistic standing cases turn on framing.²⁹⁶ A future threat of physical harm can be re-framed as a present risk, causing anxiety, distress, or economic impact in the here and now. Generally speaking, the limits of federal jurisdiction should not be a function of artful pleading. At the same time, we do not find in Article III any comprehensive rule about the particular types of injuries that suffice for standing. That tells us that the substantive law underlying a plaintiff’s claim must predominantly shape what interests count for standing, with an outer bound composed by the Court’s insistence on a constitutional floor of actual, de facto injury. The interaction of those two principles is necessarily messy. But our framework will hopefully help courts focus on the right questions.

IV. Imminence, the Timing Doctrines, and Remedies

Much of the difficulty in probabilistic standing cases arises because plaintiffs invoke injuries that have not happened yet. In those cases, the key requirement of contemporary standing doctrine is that the injury must be “actual or imminent, not conjectural or hypothetical.”²⁹⁷ As already noted, this imminence requirement for standing has both a probability dimension (how likely is the injury), and a temporal dimension (how soon is it likely to occur). These dimensions are related: If harm is unlikely, it might take a long time to come about, and if anticipated harm is far in the future, the likelihood that some circumstances may intervene to prevent it goes up. We have already argued that courts should not seek to establish some minimum probability threshold for standing.²⁹⁸ In this Part, we contend that the temporal dimension of “imminence” should be handled largely under the timing doctrines of ripeness and mootness, as well as the law of remedies.

We have two key goals in this Part. The first is to stave off a growing tendency among courts and litigants to conflate standing and ripeness by highlighting some important differences between the doctrines. Those differences make ripeness—and sometimes its close relation, mootness—a more supple instrument for pursuing the values that justiciability doctrine seeks to protect in future injury cases. Conversely, we contend that the “imminence” language in the Court’s standing cases should be read as an allusion to the timing doctrines—not as an alternative temporal principle distinctive to standing.

Our second objective is to explore the role that the law of remedies plays in justiciability.²⁹⁹ We have already criticized the most common formulation of the “remedial standing” rule, but one cannot deny that the remedy sought in a case has a great deal to do with what it takes to establish standing. A better understanding of timing and remedial doctrines would, in turn, help clarify the perennial puzzle of how much justiciability doctrine is constitutional in nature and how much is prudential.

A. Standing, Ripeness, and Mootness

The black letter law of justiciability has always distinguished between standing and the timing doctrines. Dean Chemerinsky, for instance, writes that “[w]hile standing is concerned with who is a proper party to litigate a particular matter, ripeness and mootness determine when that litigation may occur.”³⁰⁰ Particular litigants may be the right parties to bring a particular suit and yet be tossed out of court because they have sued too early or too late.³⁰¹ Despite this sharp distinction in the abstract, in practice contemporary courts—and some commentators—have tended to conflate standing, ripeness, and mootness. This tendency sows considerable confusion in the doctrine by eliding important differences in the relevant standards and the constitutional or prudential nature of their requirements. Further, the availability of two parallel tracks for deciding the same timing issues invites doctrinal manipulation. Most important for present purposes, conflating standing with ripeness and mootness obviates the distinctive role that the timing doctrines can play in addressing probabilistic injury problems.

The most common tendency is to merge or conflate standing and ripeness when a lawsuit rests on concerns about what might happen in the future. In Trump v. New York, for example, the plaintiffs alleged that a plan to exclude aliens lacking lawful immigration status from being counted in the census would violate the law and significantly affect congressional representation and federal funding.³⁰² The Court dismissed the case based on “[t]wo related doctrines of justiciability”—standing and ripeness—because it was highly uncertain how many aliens without lawful status would actually be excluded from the count.³⁰³ “At the end of the day,” said the Court, “the standing and ripeness inquiries both lead to the conclusion that judicial resolution of this dispute is premature.”³⁰⁴ Other decisions on the timing of litigation have overlooked ripeness altogether. In McConnell v. Federal Election Commission, for instance, the Court held that a politician could not challenge restrictions on campaign advertising that would not affect him until he ran for re-election in five years.³⁰⁵ The Court said that “[t]his alleged injury in fact is too remote temporally to satisfy Article III standing,” without mentioning ripeness at all.³⁰⁶ Both scholars and judges have wondered whether there is any difference between the doctrines.³⁰⁷

Standing can also be difficult to distinguish from mootness. Consider City of Los Angeles v. Lyons,³⁰⁸ which we discussed in Part II.³⁰⁹ Mr. Lyons had a claim for damages based on having been placed in a chokehold in police custody. But afterwards, any claim for an injunction based on that particular encounter was arguably moot (although Lyons might have argued that it fit into one of several exceptions to that bar).³¹⁰ The Court instead held that Lyons lacked standing to seek an injunction because he had not established that any future encounter was sufficiently likely.³¹¹ Professor Fallon concluded that “[a]s a result of Lyons, standing analysis apparently has displaced the more flexible doctrine of mootness as the applicable justiciability hurdle in much federal litigation predicated on past injuries.”³¹²

Distinguishing the timing doctrines from standing is difficult in large part because all three principles rest on the fundamental requirement that a plaintiff have a personal stake in the litigation. Uncertainty about whether or to what extent the plaintiff will be affected by the law or conduct they challenge can call into question both whether they have sufficient injury to support standing and whether adjudication is appropriate at this time. As Professor Monaghan has famously observed, “[T]here is no ‘case or controversy’ once the private rights of the litigants are no longer at stake. Mootness is, therefore, the doctrine of standing set in a time frame: The requisite personal interest that must exist at the commencement of the litigation (standing) must continue throughout its existence.”³¹³ The same can be said of ripeness, which assesses whether there is sufficient threat to the plaintiff’s personal interest at the outset of litigation to support the court’s exercise of jurisdiction.³¹⁴ Or as Professor Nichol put it, “The ‘natural’ overlap between standing and ripeness analysis occurs in the measurement of the cognizability of contingent or threatened harms.”³¹⁵

Despite the overlap of standing and the timing doctrines in principle, the doctrines have evolved differently. One likely reason is that ripeness and mootness questions generally come up in actions for injunctive relief, and thus both timing doctrines reflect the highly flexible character of equity.³¹⁶ But whatever the explanation, standing and the timing doctrines apply quite different standards that focus on somewhat different concerns. As we previously noted,³¹⁷ the Abbott Laboratories test for ripeness turns on the fitness of the issues in the case for judicial review and the hardship to the parties of awaiting future litigation.³¹⁸ This test is designed not so much to limit the power of courts but “to enhance the quality of judicial decision making by ensuring that there is an adequate record to permit effective review.”³¹⁹ Hence, the Abbott Laboratories test is not generally viewed as a stringent one,³²⁰ and it adds another layer of flexibility by allowing one factor to trade off with the other in particular cases.³²¹ Mootness is likewise often less demanding than standing. As the Court wrote in Friends of the Earth, “[T]here are circumstances in which the prospect that a defendant will engage in (or resume) harmful conduct may be too speculative to support standing, but not too speculative to overcome mootness.”³²²

Standing also differs from the timing doctrines in that, aside from certain specialized rules like the third-party standing doctrine,³²³ standing is generally considered a constitutional issue while ripeness and mootness are often thought to be at least partly prudential.³²⁴ To be sure, the Court has tied both timing doctrines to the case or controversy requirement of Article III.³²⁵ But the ins and outs of both doctrines sound predominantly in prudence. Justice Harlan’s opinion in Abbott Laboratories, for example, did not even mention Article III in formulating the modern test for ripeness.³²⁶ In Buckley v. Valeo, the Court emphasized the importance of a legislative provision for expedited judicial review in upholding a pre-enforcement challenge to the Federal Election Campaign Act.³²⁷ And the Court has recognized pragmatic exceptions to the mootness doctrine—such as for injuries “capable of repetition yet evading review”³²⁸—that would be exceptionally difficult to justify were mootness a hard and fast constitutional rule.³²⁹ All three justiciability doctrines share the constitutional requirement that a case must arise from a concrete injury in fact, but when the court decides in relation to that injury’s occurrence has been governed by more flexible prudential notions.

The choice to rely on standing, ripeness, or mootness in assessing the justiciability of a particular case may have important consequences. Without a clear division of labor between the doctrines, a court may choose a demanding standard or a relatively lenient one, a constitutional analysis or a prudential one. At best, the situation is confusing and arbitrary—it raises Justice Harlan’s concern that standing may reduce to “a word game played by secret rules.”³³⁰ At worst, viewing standing and the timing doctrines as interchangeable raises the possibility of manipulating the applicable analysis to bias the outcome. The most significant cost for our present purposes, however, is that conflating standing, ripeness, and mootness obscures the distinctive ways that the timing doctrines can assist in otherwise intractable probabilistic injury cases.

Courts and commentators have been too quick to give up on the basic distinction between a doctrine that seeks the right plaintiffs (standing)³³¹ and doctrines controlling the timing of when those plaintiffs may pursue their suit (ripeness and mootness).³³² In future injury cases, both standing and the timing doctrines focus on questions of probability. Standing asks (1) whether plaintiffs are subject to the challenged action, and (2) if they are, whether they are likely to be harmed in a cognizable way. Decisions like Clapper suggest that significant uncertainty about the first question will be fatal if it cannot be resolved at the outset of litigation.³³³ Relatedly, if wrongful conduct is allegedly happening in the world but it is uncertain whether the plaintiff will be exposed to it, the focus will typically be on standing.

But if plaintiffs are subject to the alleged harmful act, then the second question—concerning whether and how the wrongful act will give rise to injury—can be better settled by the timing doctrines. If future harm is the only harm alleged, then ripeness is the relevant doctrine.³³⁴ If the plaintiff has already experienced sufficient injury to get into court but is seeking relief predicated on that injury continuing or recurring, then mootness will often be the better choice.³³⁵ But the crucial point is that both timing doctrines, being largely prudential, focus on pragmatic concerns about the court’s ability to conduct the litigation and the practical needs of the parties. Ripeness emphasizes the extent to which the record before the court is sufficiently developed to proceed and the interests of the parties in avoiding delay.³³⁶ Mootness adds consideration of the plaintiff’s interest in securing a binding judgment to forestall recurrence of the defendant’s wrongful action. These considerations are quite different—and more tractable for courts—than an effort to fix a standard for “imminence” under the standing doctrine (not to mention an effort to determine how likely a particular future injury actually is).³³⁷

The Supreme Court’s decision in United Public Workers v. Mitchell³³⁸ illustrates these concerns about providing an adequately concrete factual context for judicial review. Federal employees subject to the Hatch Act, which barred them from taking part in political campaigns, challenged the Act on constitutional grounds. The Court held that their claims were not ripe because the plaintiffs had specified the prohibited activities in which they intended to engage in general, abstract terms.³³⁹ This would have made it difficult for the Court to assess whether those activities implicated the government’s interests in preventing corruption or the appearance of corruption.³⁴⁰ As the Hart & Wechsler editors put it, “[T]here is a real issue in UPW v. Mitchell about whether the dispute was too ‘ill-defined’ to be appropriate for judicial resolution until further developments had more sharply framed the issues for decision. If ripeness doctrine has a distinctive role or focus, mustn’t this be it?”³⁴¹

This flexible, prudential inquiry is well-suited to the concerns associated with the “imminence” element of the Court’s standing jurisprudence. If plaintiffs are, or will be, subject to the challenged action—and they plead a cognizable form of actual injury with the requisite specificity—then they should generally have Article III standing to challenge it. But prudential ripeness can still usefully assess whether the Court has the requisite information to decide the case, or whether, as in Mitchell, the issue will not be fit for judicial resolution until further developments have fleshed out the record. Delay may also help avoid unnecessary resolution of constitutional issues.³⁴² Against this concern, the Court must pragmatically weigh the hardship to the plaintiff if review is delayed, including the costs of any interim precautions the plaintiff must take to avoid future harm.³⁴³ To the extent that these factors weigh against one another on a sliding scale,³⁴⁴ they preclude establishing any set doctrinal threshold for ripeness. But attempting to concoct such a threshold for “imminence” as part of the standing inquiry would both obviate the Court’s Abbott Laboratories inquiry for ripeness and sacrifice valuable flexibility on a question unsuited for categorical rules.

To be sure, prudential inquiries often elevate the discretion available to courts, and courts may sometimes abuse prudential discretion to mask decisions motivated by other concerns. But absent any textual mandate or guidance as to a probability threshold for standing, interpolating such a threshold into Article III is surely the more aggressive extension of judicial power. The ripeness criteria, moreover, focus discretionary judgment on issues falling more clearly within the judicial wheelhouse—that is, on the ability of the court to decide the case on the facts as they stand, and the hardship to the parties of delay.

B. Standing and Remedies

A final source of guidance in probabilistic injury cases is the law of remedies. Nearly two decades ago, Professor Fallon suggested that “the thesis that justiciability doctrines are deeply influenced by concerns about judicial remedies seems almost self-evidently true—even if it has seldom been stated expressly.”³⁴⁵ Fallon emphasized, however, the importance of “[i]mplicit judgments about appropriate judicial remedies”³⁴⁶—for instance, the judgment that an injunction providing for monitoring of police practices would be overly intrusive on state and local governmental prerogatives³⁴⁷—that might influence courts to construe standing or other justiciability doctrines more strictly. We build on Fallon’s work here by adding two points. The first is that remedial principles can and should interact with standing and the timing doctrines not just implicitly, but also explicitly—as part of the legal framework for establishing what justiciability doctrine requires. Second, in certain circumstances, courts should be more willing to apply the remedial rules of their own force rather than developing an “imminence” doctrine as part of standing that purports to serve the same function. This is particularly true in cases seeking injunctive relief to forestall an uncertain future harm.

In Lyons, the Court acknowledged at the outset that “case-or-controversy considerations ‘obviously shade into those determining whether the complaint states a sound basis for equitable relief.’ ”³⁴⁸ Although Professor Fallon and other commentators often seem to treat justiciability and remedial law as doctrinally autonomous,³⁴⁹ the Court’s interpretation of Article III’s “case or controversy” language has long focused on those disputes “traditionally amenable to, and resolved by, the judicial process.”³⁵⁰ Standing doctrine, in other words, is built on the traditional requirements for a lawsuit in the Anglo-American courts. It is hardly surprising, then, that the traditional rules for securing legal and equitable remedies should inform the content of standing and other rules of justiciability.

TransUnion is the best recent example. As we have already discussed, the Court distinguished sharply between remedies with regard to what sorts of harm may constitute concrete injury in fact.³⁵¹ The majority acknowledged that the threat of future harm could suffice in a suit for an injunction, but it rejected the notion that such harm could ground standing in a suit for damages.³⁵² This was true even though the Fair Credit Reporting Act specifically authorized persons who had not yet been injured by a violation of the Act’s requirements to seek statutory damages. For the Court, the longstanding rule that damages may be made available only for realized harms informed the meaning of Article III.³⁵³ At the same time, the fact that equitable relief is traditionally available to forestall unrealized future injuries would have permitted Congress to authorize injunctions for the same plaintiffs. Cognizable injury under Article III varies according to the remedy sought in a case.

The Court did muddy the waters in TransUnion, however, by stating that a plaintiff may pursue injunctive relief from future harm “at least so long as the risk of harm is sufficiently imminent and substantial.”³⁵⁴ That could mean either that standing itself requires a judgment of the harm’s imminence or simply that plaintiffs cannot secure injunctive relief under the law of remedies without showing a likelihood of imminent and substantial harm.³⁵⁵ The latter view makes considerably more sense. Just as Article III articulates no standard for how likely a risk of injury must be, so too it sets no standard for how proximate a future injury must be in time. If the federal courts were to erect such a standard, they would surely draw heavily on the existing law of remedies, which for centuries has had to determine whether a harm was sufficiently imminent to warrant equitable relief.³⁵⁶ But why not let that law simply operate of its own force? Plaintiffs who can establish that they are subject to a risk of future harm should have standing to seek an injunction against it, but they should lose a motion to dismiss or for summary judgment if they cannot establish that the harm is sufficiently imminent under the relevant remedial law.

One might object that remedial considerations should be postponed to the end of the case and not be part of any threshold determination of standing.³⁵⁷ But the norm that litigation proceeds in stages—from establishing jurisdiction to deciding the merits to formulating a remedy—has long coexisted with the possibility that a case may be dismissed at the threshold if the pleadings or summary judgment evidence are inadequate to support the plaintiff’s obligations at a later stage. Motions to dismiss may implicate the merits as well as jurisdiction, and so a plaintiff who has pleaded a claim for damages based on an unrealized harm might have their case dismissed for failure to state a claim upon which that relief can be granted.

That is not to say that everything should always be decided up front. Professor Fallon argued years ago that “[b]ecause sound decisionmaking about appropriate remedies requires sensitivity to context, the minimal requirements of standing should be set relatively low, . . . and courts should consider whether to award injunctions . . . within the more flexible frameworks of ripeness doctrine and the law of equitable remedies.”³⁵⁸ We agree and would further suggest that some courts may be inclined to unduly restrict standing in probabilistic injury cases because the remedial law has shifted not only to favor pre-enforcement review³⁵⁹ but to make preliminary injunctions routinely available.³⁶⁰ Standing, in other words, is being used as a filter for cases that courts deem premature but that permissive interpretations of ripeness and remedies would permit. We contend that this approach distorts standing doctrine, and that, if overly preemptive litigation needs to be forestalled, the timing and remedial doctrines should be tightened accordingly.

Unlike Professor Fallon, however, we contend that existing standing doctrine need not be fundamentally reframed to achieve that end. Our discussion of the definition of injuries under TransUnion demonstrated that the underlying law—including the law of remedies—plays an important role in defining what injuries are cognizable for standing purposes. And nothing in the Court’s standing jurisprudence demands that “imminence” become the basis for a separate set of temporal standards independent of established timing or remedial doctrines. Imminence is the bread and butter of ripeness, mootness, and remedies law. Standing will work better if its neighboring doctrines are allowed to shoulder part of the load.

Conclusion

Questions of probability pervade standing analysis. They affect all three core elements of Article III standing: injury, traceability, and redressability. And although the federal courts have decided a steady diet of probabilistic standing cases, no settled framework has emerged. We attribute this continuing confusion to courts and commentators asking standing doctrine to do too much, in several respects. Some scholars have sought to develop a unified theory of probabilistic standing that would apply to all sorts of cases. That approach, however, elides important distinctions between different categories of cases. We have labeled those categories uncertain exposure, uncertain injury, and uncertain causation. Each displays its own complexities, although certain themes overlap.

One of those overlapping themes is the notion that courts ordinarily should not seek to decide how probable an event must be to create standing—a task for which Article III provides little guidance and which courts are ill-positioned to assess. As Alexander Bickel said, “No answer is what the wrong question begets.”³⁶¹ Rather, courts should ask who decides questions of probability—that is, which of several available institutions (juries, agencies, legislators) is best able to make the call. We have also argued that how injuries are framed makes a considerable difference in assessing their probability. Such framing should ordinarily come from the underlying substantive law—not standing doctrine—but the Court has complicated matters by holding that Article III sets certain constraints. That floor remains relatively modest in the cases so far, leaving plenty of room for deference to the underlying law.

Finally, it is worth remembering that standing doctrine is not the only source of law limiting access to courts and judicial remedies. The Court has developed important timing doctrines of ripeness and mootness, and it should resist the temptation to collapse them all into standing. Likewise, the law of remedies has for centuries dealt with the sorts of issues concerning probabilistic future harm that most bedevil standing doctrine. Both timing and remedial doctrines serve similar functions to standing doctrine, but they do so by asking different sorts of questions. Sometimes those questions will be both more appropriate and easier for courts to answer.

Perhaps if a committee of law professors could take standing doctrine down to the studs, they could rebuild it in a way that would be both more coherent and more workable. We often find such efforts valuable and enlightening, but we have not tried to do that here. Instead, we have offered an account that conforms reasonably well to most of the decided cases (suggesting an adjustment here and there) while trying to uncover the underlying rationales of these existing doctrines. As long as the doctrines are not asked to do more work than they are designed for, they hold up surprisingly well.

* Allen M. Singer Distinguished Service Professor of Law, University of Chicago Law School.
** Alston & Bird Distinguished Professor of Law, Duke University School of Law.

For helpful comments and suggestions, we thank Jonathan Adler, Thomas Bennett, Joseph Blocher, Erin Blondel, Kathy Bradley, Zachary Clopton, Deborah DeMott, Richard Fallon, Tara Grove, Andrew Hessick, Doug Laycock, Henry Monaghan, Richard Re, Neil Siegel, and participants in faculty workshops at Duke Law School, George Washington University Law School, and the Northwestern Pritzker School of Law, as well as at the University of Chicago Law School’s Standing Doctrine Conference. We are also grateful to Sydney Engle, John Macy, Mary Gen Sanner, and Rebekah Strotman for excellent research assistance.