[1] Univ Cologne, Dept Econ, Cologne, Germany
[2] Univ Cologne, Max Planck Inst Res Collect Goods, ECONtribute, Bonn, Germany
[3] CEPR, London, England
[4] Ludwig Maximilians Univ Munchen, ifo Inst Econ Res, bidt Grad Ctr, Munich, Germany
[5] CESifo, Munich, Germany
[6] Univ Innsbruck, Innsbruck, Austria
[7] Katholieke Univ Leuven, Leuven, Belgium