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...

In this explorative study, we adopt a knowledge-centred perspective on clusters and investigate whether clusters' internal structure explains clusters' external (knowledge) collaborative strategies. All in all, the main analytical issue underlying this paper is the following: do internal...