There is considerable and growing attention and interest on understanding what works, where, how, and why in development. This also means there are numerous debates on how best we ought to generate evidence and measure development success and impact. One way of measuring development impact is through randomized control trials (RCTs), which have been very useful for establishing causal relationships and providing robust and reliable evidence for evaluating the effectiveness and safety of development programs.While some regard RCTs as the gold standard, others are more critical of using it to measure what works. Critics argue that it is not just about 'what works,' but 'why things work' which should be prioritized when designing effective policies and interventions that can be scaled up. Another related aspect in this context is the generalizability puzzle, i.e., whether the results of a specific program can be generalized to other contexts. For example, there are questions about whether a study can inform policy only in the location in which it was undertaken. Should policymakers mainly rely on whatever evidence is available locally, even if it is not of very good quality? There is also the question of whether a new local randomized evaluation should be undertaken before an attempt to scale up and the number of times such evaluations should be repeated before scaling up.Rachel Glennerster is an Associate Professor of Economics at the University of Chicago. She uses randomized trials to study democracy and accountability, health, education, microfinance, and women’s empowerment mainly in West Africa and South Asia. Rachel spent 13 years as the executive director of the Abdul Latif Jameel Poverty Action Lab (J-PAL) at MIT, a key leader in popularizing RCTs in development economics. Thereafter she served as chief economist of the United Kingdom’s Foreign, Commonwealth and Development Office (FCDO). Twitter: @rglennerKey highlights:Introduction - 00:44Asking the right questions and answering them correctly - 03:45The added-value of RCTs and critique - 08:00The generalizability puzzle - 17:37Education and learning - 23:20Microfinance in India - 26:13Improving public services through participation - 34:30Impact of the media in Burkina Faso - 38:38Translating evidence into policy - 46:00Host:Professor Dan Banik (Twitter: @danbanik  @GlobalDevPod)Apple Google Spotify YouTubeSubscribe: https://globaldevpod.substack.com/https://in-pursuit-of-development.simplecast.com/