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

Abstract

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 significant. We also provide cross-country evidence corroborating our findings.JEL Classification: F14, J12, N17, O55

African polygamy: Past and present

“…I find, by contrast, that polygamy is least common in those parts of Africa where women have historically been most important in agriculture. Third, I confirm the result of Dalton and Leung (2011); greater slave trade exposure does predict polygamy today. My approach differs from theirs in several ways -I take women as the unit of observation rather than men, I include Angola (a low-polygamy country that was the hardest hit by the Atlantic slave trade), and I take locations rather than ethnic groups as the unit of treatment.…”

“…Whatley and Gillezeau (2010) have shown that there is a correlation between slaves taken from points along the coast and the degree of polygamy among coastal groups recorded in the Ethnographic Atlas. Recently, Dalton and Leung (2011) have used DHS data to find a correlation that is robust to the instrumental variables strategy used by Nunn (2008) -predicting slave exports using distance from new world ports. I confirm their result using different methods.…”

“…Second, because the estimates in Nunn and Wantchekon (2011) are reported in a map of ethnic groups, I use respondents' geographic coordinates to join them to these measures of slave trade intensity over space. Following Dalton and Leung (2011), I use the log of (one plus) Atlantic slave trade exports normalized by area to measure slave trade exposure. Standard errors are clustered at the ethnic-group level.…”

Climate and the slave trade

“…Finally, Dalton and Leung (2013) and Edlund and Ku (2014) have suggested that the slave trade changed the role of women in African society. We use the Demographic and Health Surveys to show that higher temperatures during the slave trade predict better outcomes for women today.…”

The legacies of slavery in and out of Africa

“…Dalton and Leung (2014) combine the historical data on the slave trades from Nunn (2008a) and Nunn and Wantchekon (2011) with contemporaneous polygyny data from the female Demographic and Health Surveys (DHS). They show that the higher polygyny rates in Western Africa, if compared to Eastern Africa, can be explained by the slave trades, since the preference for male slaves was a distinctive feature of the trans-Atlantic trade out of Western Africa, while the opposite occurred for the Indian Ocean and Red Sea trades out of Eastern Africa.…”