Econometrics for evaluations: An introduction to recent developments

There has recently been a rapid expansion of interest in the econometrics of program evaluation, both within Australia and around the world. We provide a review of the key issues and recent developments in this field. A central feature of recent developments is the attempt to allow for program impacts that vary across individuals. This contrasts with earlier econometric approaches that implicitly assumed a homogeneous treatment effect. We survey alternative nonexperimental estimation strategies and note that they can be characterised by (1) an assumption about how untreated outcomes vary across individuals: this assumption in turn suggests how the counter-factual untreated outcomes of program participants should be estimated, and (2) the way in which the estimator aggregates or weights the program impacts of different individuals in the treatment group. We also emphasise the importance of good data.