Randomized experiments provide policy relevant treatment effects if there are no spillovers between participants and nonparticipants. We show that this assumption is violated for a Danish activation program for unemployed workers. Using a difference-in-difference model we show that the...

This paper examines the effects of daily outdoor air pollution variation on student test scores. Using Danish register data for all elementary and lower secondary students, we link home addresses to a 1 km x 1 km pollution grid to measure test day and lifetime pollution exposure. An increase in...