International development is an academic discipline concerned with the social and economic progress in impoverished regions. In particular, researchers seek to determine what factors explain differences in rates of development. Women's education is one of the major explanatory variables behind the rates of social and economic development,[1] and has been shown to have a positive correlation with both.[2][3] According to notable economist Lawrence Summers, “investment in the education of girls may well be the highest-return investment available in the developing world.”[2] Closing gender disparity is also one of the U.N. Millennium Developmental Goals.[4]