One of the best ways for a nation to develop is to provide equal opportunities for education for its girls, followed closely by easy availability to clean water and sanitation, the latter two being important factors in improving health and life expectancy. Although education for girls may seem to be an unmitigated good, there are many factors that work against it.
There are of course religious bigots, found especially but not exclusively in some Muslim societies, that oppose it for religious reasons. But there are secular factors working against it too. One is that girls offer free labor in the home, helping in the cooking and cleaning and child-rearing, and often spending hours each days carrying water from distant places. Another is that young girls are often given in marriage at an early age and the dowry the family receives can be an important source of income for the family.
Sesame Street has a global campaign to encourage the expansion of education for girls and has produced one if its well-designed clips.