Polygamy as a Ponzi Scheme

In Sub-Saharan Africa, polygamy is very prevalent: 10 to 50% of married women are in a polygamous union depending on the country. Yet, historically, the fraction of men who never marry has always been low. This is because a fast population growth combined with a large age gap between husbands and wives created a surplus of women on the marriage market. However, this surplus is projected to shrink as population growth has started to slow down. The demographic conditions necessary to sustain high levels of polygamy while ensuring that all men eventually marry are therefore less likely to hold in the future. What will be the effect on the marriage market? Will polygamy disappear or will male involuntary celibacy explode? The paper presented in this Mannheim Applied Seminar develops a structural model to study under which conditions the authors should observe a decrease in the share of polygamous men and/or an increase in the share of single men when population growth declines. They provide an empirical application using original data from Senegal.