1. Faculty of Business and Economics, University of Basel, Peter-Merian-Weg 6, Postfach, CH-4002 Basel, Switzerland.
2. Department of Economics, University of Pennsylvania, 3718 Locust Walk, Philadelphia, PA 19104.
3. Department of Finance and Department of Economics, University of Wisconsin–Madison, 975 University Ave., Madison, WI 53706, and Federal Reserve Bank of Minneapolis, 90 Hennepin Ave., Minneapolis, MN 55401.