Polygyny and the Economic Determinants of Family Formation in Sub-Saharan Africa,

Social norms and formal institutions governing marriage markets vary widely across societies. This paper examines how polygyny norms in Sub-Saharan Africa shape marriage market responses to aggregate economic shocks and their resulting welfare implications. Unlike monogamous markets, polygynous markets feature intense competition for brides between young bachelors and older married men seeking a second (junior) wife. I show, both theoretically and empirically, that the latter group is more responsive than the former to aggregate income shocks in areas where the shadow price of marrying a junior wife is low. This difference in sensitivity leads to distinct equilibrium outcomes: adverse shocks increase the incidence of child marriage in monogamous areas but have no detectable effect in polygynous areas. These divergent equilibrium outcomes generate stark differences in the long-term effects of such shocks on female education, literacy, and the utilization of preventive care services.