Beyond “what works”: why impact evaluations need implementation research Lelys Dinarte-Diaz May 13, 2026 This page in: English © 2026 The World Bank Group,

https://blogs.worldbank.org/en/impactevaluations/beyond--what-works---why-impact-evaluations-need-implementation- For many of us conducting RCTs to evaluate pilots of interventions, an exciting stage is when we are invited by government officials to present the results. After we have presented the main impacts of the intervention, government officials usually ask: "This program is great and I am interested in implementing it at the national level. How can I do that? What conditions need to be met to implement the program at scale and make sure that we can still get similar impacts?" These are fair questions, as there is already evidence showing that what works in controlled experimental settings does not always hold in weak public institutions. © 2026 The World Bank Group,