Perhaps this topic needs a little public choice analysis:
Many Sub-Saharan African countries are extremely poor. It has been argued that the marriage system (in particular polygyny) is one contributing factor to the lack of development in this region. Polygyny leads to low incentives to save, depressing the capital stock and output. Enforcing monogamy might seem like an obvious solution. However, such a law will have winners and losers. In this paper, we investigate the transition from a polygynous to a monogamous steady state. We find that the initial old men will be big losers. The reason is that they had married many wives in anticipation of the brideprice that future daughters will fetch. However, due to the marriage reform, the value of daughters depreciates rapidly, as the brideprice changes from positive to negative. This increases savings and thereby the aggregate capital stock. The interest rate falls and the initial young suffer a loss in capital income. Thus, all men alive during the reform period experience a loss in utility. Young women and all future generations will benefit. However, the future gains are not enough to compensate the losers. This may explain why many African countries experience strong resistance to changing their marriage laws.