When Will We Ever Learn? Improving Lives through Impact Evaluation

Successful programs to improve health, literacy and learning, and household economic conditions are an essential part of global progress. Yet after decades in which development agencies have disbursed billions of dollars for social programs, and developing country
governments and nongovernmental organizations (NGOs) have spent hundreds of billions more, it is deeply disappointing to recognize that we know relatively little about the net impact of most of these social programs. Addressing this gap, and systematically building evidence about what works in social development, would make it possible to improve the effectiveness
of domestic spending and development assistance by bringing vital knowledge into the service of policymaking and program design. In 2004 the Center for Global Development, with support from the Bill & Melinda Gates Foundation and The William and Flora Hewlett Foundation, convened the Evaluation Gap Working Group. The group was asked to
investigate why rigorous impact evaluations of social development programs, whether financed directly by developing country governments or supported by international aid, are relatively rare. The Working Group was charged with developing proposals to stimulate more and better impact evaluations (see appendix A).

The initiative focused on social sector program evaluations because of their high profile in international fora (the Millennium Development Goals are an example). The Working Group deliberated during 18 months and consulted with more than 100 policymakers, project managers, agency staff, and evaluation experts through interviews and meetings (see appendix C). This report is the culmination of that process.