Polygyny as a determinant of migration

We hypothesize that polygyny acts as a significant push factor for migration in sub-Saharan Africa because it is associated with competition within polygynous families and on the marriage market, while also contributing to unfavorable economic and political outcomes at the societal level. Using cross-country data from 46 sub-Saharan African countries, we show that higher polygyny prevalence is associated with increased international emigration. We complement this macro-level evidence with original survey data from Senegal, the Gambia, and Nigeria. We show that polygyny is also associated with higher migration aspirations and observed migration of survey respondents’ siblings at the individual level. Respondents from polygynous families tend to report stronger economic motives for migration, while those concerned about the marriage market effects of polygyny—regardless of family background—are more likely to consider migrating for marriage. This highlights two distinct pathways—competition within polygynous families and on marriage markets—linking polygyny to migration.