The marriage squeeze: Measuring and explaining marriage market dynamics in Sub-Saharan Africa

Marriage market imbalances have been linked to social instability, crime, and reduced welfare in both developing and developed countries. We revisit this issue in the context of Sub-Saharan Africa, where high population growth and the prevalence of polygyny shape partner availability in structurally significant ways. Building on a dynamic model of the marriage market, we introduce a novel measure that accounts explicitly for the intensity of polygyny and apply it to Demographic and Health Survey data from 1991 to 2023. We show that conventional marriage ratios, which ignore polygyny, understate the extent of male-biased competition in the marriage market. When polygyny is incorporated, we find that marriage imbalances have persisted at structurally high levels since 2006, especially in rural areas and among Muslim populations. These patterns are driven by demographic transitions - declining population growth and narrowing partner age gaps - that amplify the impact of polygyny on male surplus. Our findings highlight the importance of accounting for marriage market dynamics in the design of policies related to demographic change, family formation, and social stability in low-income settings.