RT Journal Article SR Electronic T1 Heterogeneous Employment Effects of Job Search Programmes: A Machine Learning Approach JF Journal of Human Resources JO J Hum Resour FD University of Wisconsin Press SP 0718-9615R1 DO 10.3368/jhr.57.2.0718-9615R1 A1 Knaus, Michael C. A1 Lechner, Michael A1 Strittmatter, Anthony YR 2020 UL http://jhr.uwpress.org/content/early/2020/03/24/jhr.57.2.0718-9615R1.abstract AB We systematically investigate the effect heterogeneity of job search programmes for unemployed workers. To investigate possibly heterogeneous employment effects, we combine non-experimental causal empirical models with Lasso-type estimators. The empirical analyses are based on rich administrative data from Swiss social security records. We find considerable heterogeneities during the first six months after the start of training. Consistent with previous results in the literature, unemployed persons with fewer employment opportunities profit more from participating in these programmes. Finally, we show the potential of easy-to-implement programme participation rules for improving average employment effects of these active labour market programmes.