Countries with a large share of their populations who are adolescents or young people have an opportunity to reap a substantial demographic bonus for their nations’ economies, development, resilience and productivity. This requires investing in adolescents’ and young peoples human capital and expanding the range of choices and opportunities available to them. But many adolescents, especially girls, are denied the investments and opportunities that would enable them to realize their full potential. For example, 26 per cent of the world’s adolescent girls and 17 per cent of boys between the ages of 11 and 15 are not in school.