Polygyny, Timing of Marriage and Economic Shocks in Sub-Saharan Africa

This paper studies how local polygyny norms affect the equilibrium response of marriage markets to short-term changes in aggregate economic conditions. It develops a simple equilibrium marriage market framework with overlapping generations in which polygyny is modeled as a sequential one-to-one matching. The model generates predictions that are tested by revisiting the impact of rainfall shocks on the timing of marriage in Sub-Saharan Africa. Consistent with the model’s predictions, I find that the effect of droughts on child marriage is weaker where polygyny is more commonly practiced. The same shock leads to a large increase in the annual hazard of child marriage in monogamous areas but has no detectable effect in areas with high polygyny levels. In these areas, there is instead an increase in the market shares of young men that are looking for first/unique spouses at the expense of older men that are looking for second spouses. The differences in equilibrium outcomes on the marriage markets translate into differences in fertility onset and long term fertility levels.