“Sorting through heterogeneity of impact to enhance policy learning”
The World Bank; November 29, 2012
The demand and expectation for concrete policy learning from impact evaluation are high. Quite often we don’t want to know only the basic question that impact evaluation addresses: “what is the impact of intervention X on outcome Y in setting Z”. We also want to know the why and the how behind these observed impacts. The World Bank impact evaluation group features work by Angrist, Pathak, and Walters on heterogeneous treatment effects in their study of charter school effectiveness.