This paper addresses the selection of smoothing parameters for estimating the average treatment effect on the treated using matching methods. Because precise estimation of the expected counterfactual is particularly important in regions containing the mass of the treated units, we define and...

This paper evaluates the UK New Deal for Lone Parents (NDLP) program, which aims to return lone parents to work. Using rich administrative data on benefit receipt histories and a "selection on observed variables" identification strategy, we find that the program modestly reduces benefit receipt...

Estimation, inference and interpretation of the causal effects of programs and policies have all advanced dramatically over the past 25 years. We highlight three particularly important intellectual trends: an improved appreciation of the substantive importance of heterogeneous responses and of...