to establish impact, attributing observed changes in welfare to the intervention, while identifying key factors of success. Impact evaluations are aimed at providing feedback to help improve the design of programs and policies. They also provide greater accountability and a tool for dynamic learning, allowing policymakers to improve ongoing programs and ultimately better allocate funds across programs. Such a causal analysis is essential for understanding the relative role of alternative interventions in reducing poverty. The papers in this section again adopt a variety of techniques. The rst...