The typical evaluation problem aims at quantifying the impact of a ÔtreatmentÕ (e.g. a training programme, a reform, or a medicine) on an outcome of interest (such as earnings, school attendance or illness indicators), where a group of units, the ÔtreatedÕ, receive the ÔtreatmentÕ, while a...

Matching, especially in its propensity-score flavors, has become an extremely popular evaluation method. Matching is, in fact, the best-available method for selecting a matched (or reweighted) comparison group that looks like the treatment group of interest. In this talk, I will introduce...

We highlight the importance of randomisation bias, a situation where the process of participation in a social experiment has been affected by randomisation per se. We illustrate how this has happened in the case of the UK Employment Retention and Advancement (ERA) experiment, in which over one...

One of the most powerful critiques of the use of randomised experiments in the social sciences is the possibility that individuals might react to the randomisation itself, thereby rendering the causal inference from the experiment irrelevant for policy purposes. In this paper we set out a...