The Family Law Doctrine of Equivalence

Students of patent law learn the doctrine of equivalents. According to the doctrine, a patent protects an invention that does “the same work in substantially the same way, and accomplish[ es] substantially the same result,” as the device described in the patent, even if it differs “‘in name, form, or shape.” In her new book, Nancy Polikoff has fashioned something like a parallel doctrine for families. Let’s call it (with a slight play on words) the family law Doctrine of Equivalence. In today’s world, according to Polikoff, a broad set of relationships now plays the same role as marriage and traditional families once did in people’s lives. Conventional forms of family should thus receive no special legal protection. Rather, the law should extend similar privileges to the range of living arrangements that individuals choose for themselves.