Why is Polygyny More Prevalent in Western Africa?: An African Slave Trade Perspective

Polygyny rates are higher in Western Africa than in Eastern Africa. The African slave trades explain this difference. More male slaves were exported in the trans-Atlantic slave trades from Western Africa, while more female slaves were exported in the Indian Ocean and Red Sea slave trades from Eastern Africa. The slave trades led to prolonged periods of abnormal sex ratios, which impacted the rates of polygyny across Africa. In order to assess these claims, we construct a unique ethnicity-level data set linking current rates of polygyny with historical trade flow data from the African slave trades. Our OLS estimates show a positive correlation between the trans-Atlantic slave trades and polygyny. An IV approach shows the relationship is causal and statistically signicant. We also provide cross-country evidence corroborating our findings.