[1] Hanken Sch Econ, Dept Econ, POB 479, FI-00101 Helsinki, Finland
[2] Univ Jyvaskyla, Jyvaskyla, Finland
[3] Norwegian Sch Econ, Dept Econ, N-5045 Bergen, Norway
[4] CEPR, London, England
[5] Aalto Univ, Sch Business, Dept Econ, POB 21240, FI-0076 Aalto, Finland
[6] Helsinki Grad Sch Econ, Helsinki, Finland
[7] Katholieke Univ Leuven, Leuven, Belgium