Abstract

This chapter provides an account of the early origins and later development of the category of unjust enrichment law in the United States – the first common law jurisdiction to give the subject independent taxonomic space. It examines the reasons why the first formal statement of the subject in that jurisdiction in 1932 bore the title ‘restitution’, not ‘unjust enrichment’. As it explains, the reasons were as much to do with the preference of its publishers for brevity as any other reason. This may be criticised as a mistake from a taxonomic point of view, because all of the other categories of private law with which we are familiar (contract, for example) identify particular types of event (causes of action) giving rise to legal claims, not particular sorts of remedy, and restitution is a remedy, not a cause of action. However, the chapter argues that the adopted approach rightly acknowledged the uncertain boundaries and content of the field, preferring a taxonomy that captured potentially relevant claims over one that potentially omitted them prematurely. On this approach, unjust enrichment is akin to the law of torts in the sense that it is a conglomeration of different causes of action, with only limited, stable features in common. _