Job-search periods for welfare applicants : evidence from a randomized experiment / Jonneke Bolhaar (Netherlands Bureau for Economic Policy Analysis (CPB) and VU University Amsterdam), Nadine Ketel (University of Gothenburg and IZA), Nadine Ketel (University of Gothenburg and IZA), Bas van der Klaauw (VU University Amsterdam, Tinbergen Institute, CEPR and IZA) ; IZA. Bonn : IZA, March 2016