Overall, the economic and social costs of child marriage, early childbearing, and low educational attainment for girls are large. This note is part of a series that discusses trends in girls’ education, child marriage, and early childbearing, their impacts on a wide range of development outcomes, and the policies and programs that could improve opportunities for adolescent girls. The analysis builds on work at the World Bank on the cost of not investing in girls, and on a previous global study on the economic impacts of child marriage conducted by the World Bank in partnership with the International Center for Research on Women. The conceptual framework for the analysis is provided in appendix.