We test whether financial incentives have an effect on weight reduction in a randomized controlled trial involving 700 obese persons assigned to three experimental groups. While two treatment groups obtain €150 and €300, respectively, for achieving an individually assigned target weight...

This paper examines the effect of copayments on doctor visits using the German health care reform of 2004 as a natural experiment. In January 2004, copayments of 10 euros for the first doctor visit in each quarter have been introduced for all adults in the statutory health insurance. Individuals...

This paper estimates causal effects of two Polish active labor market policies - Training and Intervention Works - on employment probabilities. Using data from the 18th wave of the Polish Labor Force Survey we discuss three stages of an appropriately designed matching procedure and demonstrate...

The evaluation of interventions such as active labor market policies or medical programs by means of a randomized controlled trial is often considered the gold standard. However, randomized experiments might face severe shortcomings especially if performed at the group level. One such problem is...

This paper provides micro-econometric evidence on the effectiveness of Active Labor Market Policies (ALMP) in Poland. We sketch the theoretical framework of matching estimators as a substitute for randomization in labor market programs. Using retrospective data from the 18th wave of the Polish...

Propensity score matching is a prominent strategy to reduce imbalance in observational studies. However, if imbalance is considerable and the control reservoir is small, either one has to match one control to several treated units or, alternatively, discard many treated persons. The first...