And the body of knowledge on adolescent development and participation - in terms of data and analysis, best practices and lessons learned, and understanding of disparities and bottlenecks - is steadily growing. As this report points out in Chapter 2, the number of adolescents is expected to increase, especially in poor countries. Many key development agents have already joined in a global consensus on the importance of investing in adolescence and youth. These stakeholders, at all levels, must now pull together to support young people in developing the skills and capacities they need to pull themselves out of poverty.