[1] Queen Mary Univ London, Ctr Econ Performance, Ctr Econ Policy Res, London, England
[2] Queen Mary Univ London, Inst Study Labor IZA, London, England
[3] Univ Pompeu Fabra, Barcelona Grad Sch Econ, Barcelona, Spain
[4] Univ Pompeu Fabra, Ctr Econ Policy Res, Barcelona, Spain