Preventing NEETs during the Great Recession : the effects of a mandatory activation program for young welfare recipients / Emile Cammeraat (Leiden University), Egbert Jongen (CPB Netherlands Bureau for Economic Policy Analysis and Leiden University), Pierre Koning (Leiden University, VU University Amsterdam, Tinbergen Institute and IZA) ; IZA Institute of Labor Economics. Bonn, Germany : IZA Institute of Labor Economics, October 2017