For me this was the stand-out chart from Esther Duflo’s recent TED talk. Apparently providing information on the returns to education does even better than deworming for increasing school attendance.
I am somewhat surprised that there haven’t been more efforts to replicate the Kenya deworming finding, which is quite old now (noting that there is one study on India here – but what about other African countries?). A key defence of the randomistas position is that external validity can be improved by replication of findings in different settings. The incentives probably aren’t there for academics to do boring replication studies, but surely there is an incentive for donors to want to fund such studies?