1. Department of Economics, University of Bologna
2. Lear, Rome
3. Department of Economics, University of Bologna, Toulouse School of Economics and CEPR, London
4. Deutsches Institut fuer Wirtschaftsforschung (DIW Berlin), Department of Economics, Technical University (TU) Berlin, CEPR, London and CESifo, Munich
5. Lear, Rome and Department of Economics, University of Bologna