The Transformation of Polygyny in Sub-Saharan Africa

As the rest of the developing world, Sub-Saharan Africa has experienced profound transformations in the institution of marriage. Yet, unlike most other regions, polygyny has remained widespread across the subcontinent. There is, however, evidence to suggest that the practice of polygyny is declining and that selection into polygynous unions based on sociodemographic characteristics is increasing as sub-Saharan Africa undergoes rapid sociocultural, demographic, and economic change. Using data from 111 Demographic and Health Surveys conducted in 27 countries since the 1990s, we study recent trends in the prevalence of polygyny among currently married women, examine sociodemographic characteristics of women in polygynous unions, and test whether selection on these characteristics into polygynous unions has increased over time. We find that, net of other factors, the likelihood of being in a polygynous union has declined in most countries. We show that women who are less educated, non-Christian, and living in rural areas are more likely to be in a polygynous union and that in many countries, selection into polygynous unions on these characteristics has been growing. These findings contribute to the broader literature on marital and family change by providing new insights into recent trends in and patterns of polygyny across the subcontinent.