1. Department of Economics, University of Chicago, 1126 East 59th Street, Chicago, IL 60637 (email: )
2. Banque de France, Direction des Etudes Monétaires et Financières, DGEIDEMFI, 41-1403, 31 rue Croix-des-petits-champs, 75049 Paris Cedex 01, France (email: )
3. University of Sassari and Einaudi Institute for Economics and Finance (EIEF), Via Sallustiana 62, 00184 Rome, Italy (email: )