Though Sub-Saharan Africa is seen to make absolute progress towards gender equality over the period, the gap between it and the leading regions has increased. ( As explained in the introduction, over the past 20 years researchers and policy-makers have started to pay more attention to gender equality as one of the core drivers of economic development. Tertilt (2005), for example, concludes that enforcing a ban on polygyny decreases fertility by 40%, increases the savings rate by 70%, and increases output per capita by 170%.