1. Department of Economics, University of Minnesota, 4-101 Hanson Hall, 1925 Fourth Street South, Minneapolis, MN 55455, and Federal Reserve Bank of Minneapolis (e-mail: )
2. Finance Department, The Wharton School, University of Pennsylvania, 2322 Steinberg-Dietrich Hall, 3620 Locust Walk, Philadelphia, PA 19104 (e-mail: )
3. Tepper School of Business, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (e-mail: ).