This paper proposes a difference-in-differences approach for disentangling a total treatment effect on some outcome into a direct impact as well as an indirect effect operating through a binary intermediate variable - or mediator - within strata defined upon how the mediator reacts to the...

Many countries subsidize low-income employments or small jobs. These subsidies and their phasing out can generate labor market frictions and distort incentives. The German Minijob program subsidizes low-income jobs. It generates a 'Minijob trap' with substantial bunching along the earnings...

The German government provides discretionary investment grants to structurally weak regions to reduce regional disparities. We use a regression discontinuity design that exploits an exogenous discrete jump in the probability of receiving investment grants, to identify the causal effects of the...

This paper shows that import exposure affects voting behavior because it affects local labor markets. We develop a new framework for mediation analysis where one instrumental variable is sufficient to identify three causal effects. Using German data from 1987-2009, we find that import exposure...

This paper investigates the link between variation in the supply of workers who participate in specific types of active labour market policies (ALMPs) and firm performance using a new exceptionally informative German employer-employee data base. For identification we exploit that German local...