This essay analyzes critically the existing literature to show how State law tends to control relationships and disputes between people that are strangers to each other because, whenever there is a bond tying together a group of people, such a group tends to have their relationships and disputes controlled by different sets of rules. These “different” rules may have diverse origins (customary, religious, professional), but they are daily relied on by dozens of millions of people; they control U.S. markets worth dozens of billions of USD, and they all serve the purpose of regulating activities, for which State law is perceived by the concerned group as unfit (or, at most, as a second best choice) to meet their needs.
