The impact of development impact research
TIME keynote, November 2025
Macartan Humphreys
The plan
- What convinced me of the need for randomized interventions [Sierra Leone DDR]
- Some big early investments, and poor returns: How little we know! [DRC study]
- A flourishing of studies, innovations, sectoral learning, high level take-aways [Many studies]
- What’s been picked up, what’s been set aside? [Many anecdotes]
- Where to from here? [Some sage reflections]
Headlines
- We have learned a lot about how to figure out the effectiveness of development interventions
- We have learned a lot about what kinds of interventions seem to work, with results very often going against intuitions
- We have learned that many interventions have weak effects at best and that effects are likely very heterogeneous
- Some of this learning appears to translate into changes in practice, but pickup is uneven
And:
Everything we—researchers and practitioners—have learned, points to the need to be modest about our knowledge, attuned to the role of context, and open to learning from different approaches
As development resources become scarce, the need to focus on learning becomes stronger than ever, especially for addressing the biggest questions
1. An interest in impacts
The road from TCD, 1994
The road from TCD, 1994
Development to Conflict (1996)
