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...

We adapt the models of Menzio and Moen (2010) and Snell and Thomas (2010) to consider a labour market in which firms can commit to wage contracts but cannot commit not to replace incumbent workers. Workers are risk averse, so that there exists an incentive for firms to smooth wages. Real wages...