1. Department of Economics, University of Sassari, Ente L. Einaudi for Monetary Banking and Financial Studies, Via Due Macelli 73, Rome 00187, Italy, and CEPR.
2. Kellogg School of Management, Northwestern University, Evanston, IL 60208, and CEPR.
3. Graduate School of Business, University of Chicago, 1101 East 58th Street, Chicago, IL 60637, NBER, and CEPR.