Varying biases in matching estimates: Evidence from two randomised job search training experiments

We compare various matching estimators with the results from two randomised field experiments that evaluate the employment effects of job search training programmes. We find that commonly used non-experimental matching estimators tend to overestimate the programme effects, especially in the first experiment in which participation in the programme is voluntary. In the second experiment, where caseworkers assign unemployed persons to the training programme, the matching methods produce estimates that are close to the experimental results.