In many developing nations, young women have lower enrollment rates in secondary school than do young men. describe several ways in which greater educational opportunities for young women could lead to faster economic growth in these countries

One way is that those women could join the work force, and specifically, they could be a skilled work force - this would increase the competitiveness of the market. Basically, the number of the skilled workers would double (assuming no women are in the market in the beginning - that's a lot of new workers that would enrich the market!)

More educated women would also pay more attention to the education of their children, so their children would also more likely receive a better education - this would ensure that the economic growth is long-term.