Polygeny and Poverty

Countries where polygyny (one man married to several wives) is allowed differ from monogamous countries in several demographic characteristics: Women marry extremely early, the age-gap between husbands and wives is large, fertility is high, and typically a brideprice is paid at marriage. In monogamous countries, on the other hand, parents traditionally gave a dowry (negative brideprice) to

their daughters at marriage. Polygynous countries are also on average poorer than monogamous countries. This paper analyzes whether the marriage system can account for these observations. I present an overlapping generations model with a marriage market and endogenous fertility. Two different marriage systems are analyzed, one in which polygyny is allowed and one in which it is not (monogamy).

I find that polygyny leads to higher fertility and age gaps than monogamy, and to a positive price for women, while the equilibrium brideprice under monogamy is

negative. I also find that the capital-output ratio is lower under polygyny. The reason is that under polygyny investing in wives and selling children is an alternative investment strategy that crowds out investment in physical assets. To derive quantitative results, I calibrate the model to the average of polygynous countries. I find that banning polygyny decreases fertility by 40%, compared to a 30% difference in the data. The savings rate goes up by 30% and output per capita increases 150%, which is close to the observed empirical differences.

For more information, contact Jere Behrman.