This paper reviews the stylized facts regarding the levels of human capital investments and the returns to those investments in developing countries. It shows that 23% of children in developing countries do not complete the fifth grade and of these, 55% started school but dropped out. We argue that eliminating dropouts is the most cost effective way to make progress on the goal of Universal Primary Education. Of the various mechanisms we can use, mechanisms that stimulate schooling demand have the strongest evidence of success to date and are the most cost effective.