In 2006, when a CGD working group, led by Ruth Levine, Bill Savedoff, and Nancy Birdsall, published its report When Will We Ever Learn? Improving Lives Through Impact Evaluation, very few social programs benefitted from studies that could determine whether or not they actually make a difference. Since then, the world has seen tremendous progress in harnessing better evidence to inform public policy decision making, especially from impact evaluations of programs in low- and middle-income countries. But COVID-19 has put a spotlight on an unfinished agenda, underscoring the need for high-quality, timely, and context-specific evidence—for both effectiveness and political credibility of the response. The pandemic has demonstrated the cost in lives and livelihoods lost when policymakers make decisions based on incomplete or outdated evidence and data.

Given the potential real-world benefits, why have decision makers within governments, aid agencies, multilateral organizations, and NGOs not yet fully harnessed the value of evidence—including from impact evaluations—for better public policies? Looking ahead, how can the development community renew momentum and broaden bases of support for impact evaluation and the wider evidence agenda? These questions were the focus of a CGD Working Group on New Evidence Tools for Policy Impact, which set out to understand why these social benefits continue to go unrealized and to chart out a renewed funding agenda for greater value in government policymaking.

The working group brought together a diverse group of policymakers and experts to review recent progress and identify outstanding challenges in the use and utility of evidence for global development, with a focus on impact evaluation. The working group’s final report highlights how far the field has come in addressing persistent critiques about the scale, generalizability, and policy utility of impact evaluation methods, reflecting a nuanced and more productive global conversation. It also offers recommendations on “what and how to fund to deliver on the promise of impact evaluation and bolster the broader evidence ecosystem” as two intertwined goals. The report urges governments and development partners to do more to integrate evidence and learning into routine operations and programming, while also emphasizing how researchers can elevate implementation, delivery, and cost analyses alongside impact evaluations for greater policy relevance. By spotlighting dozens of resources and examples of good practice and policy impact, the report helps ensure we are benefiting from—and not rehashing—well-developed contributions. In doing so, this report serves as a key resource for funders, practitioners, and students.