Patrilocal Exogamy as a Monitoring Mechanism : How Inheritance and Residence Patterns Co-evolve

Economists have modeled inheritance norms assuming the pattern of post-marital residence is exogenous. We model the co-evolution of these two institutions, examining how patrilineal inheritance and patrilocal exogamy reinforced each other in a patrilineal-patrilocal equilibrium. We also derive conditions for a matrilineal-matrilocal equilibrium. The endogenous choice of the old to monitor the sexual behavior of the young women who reside with them, thereby affecting the paternity confidence of the young women’s husbands and hence their incentives, is crucial. Our model fits the data on the relationship between inheritance, residence patterns and paternity confidence, and on the importance of paternity uncertainty. Sed quis custodiet ipsos custodes? (D Juvenal 1895, Liber secundus, Satura VI, 325, lines 347-8.)