One of the striking features of private law in English-speaking countries is the extent to which it is mainly common law. To be sure, many areas of tort, contract, and property are subject to statutes, and civil law jurisdictions demonstrate that private law can be codified. Still, most Anglo-American private law is common law. This chapter explores that relationship. Both private law and the common law fit awkwardly into the dominant theoretical models of law, which emphasize regulation and social control by the state. Thus, the common law has long been criticized for failing to comply with the model of clearly articulated rules that are announced ex ante and applied ex post. The private law, for its part, contains numerous features that make it a poor candidate for a well-designed regulatory regime. Law and economics (L&E) has dominated much of contemporary private law theory. Beginning in the 1980s, however, neoformalist critics focused on features of private law that L&E can explain only awkwardly. These accounts, in turn, provide responses to many of the standard criticisms of the common law. While this movement is encouraging, theoretical challenges remain. Neoformalism, despite its ambition to take the structure of legal doctrine more seriously than L&E, has difficulty accounting for large swaths of private law. Furthermore, these theories have tended to be highly abstract, placing little or no significance on the particularity of the communities over which private law claims authority. In contrast, the common law often evidences a parochialism that focuses on the history or practices of specific communities. A renewed focus on the classical common law theory of the seventeenth and eighteenth centuries offers one way of responding to these weaknesses in neoformalism.
Oman, Nathan B, Private Law and Local Custom (October 11, 2019) in Oxford Handbook of New Private Law Theory (Henry Smith et al eds forthcoming).