Over the period 2005-2009 the Dutch government increased childcare subsidies substantially, reducing the average effective parental fee by 50%, and extended subsidies to so-called guestparent care. We estimate the labour supply effect of this reform with a difference-in-differences strategy,...

Randomized experiments provide policy relevant treatment effects if there areno spillovers between participants and nonparticipants. We show that thisassumption is violated for a Danish activation program for unemployed workers.Using a difference-in-difference model we show that the...