We re-analyze the effects of a Danish active labour market program social experiment that included a range of sub-treatments, including monitoring, job search assistance and training. Previous studies have shown that the overall effect of the experiment is positive. We apply newly developed non-parametric methods to determine which of the individual policies that explains the positive effect. The use of non-parametric methods to separate sub-treatment effects is important from a methodological point of view, since the alternative, namely parametric/distributional assumptions, is in conflict with the concept of experimental evidence. Our results are highly relevant in a policy perspective, as optimal labour market policy design requires knowledge on the effectiveness of specific policy measures.