1. School of Management, Yale University, 135 Prospect Street, New Haven, CT 06520, and National Bureau of Economic Research.
2. Graduate School of Business, University of Chicago, 1101 East 58th Street, Chicago, IL 60637, Federal Reserve Bank of Chicago, and National Bureau of Economic Research.
3. Graduate School of Business, University of Chicago, 1101 East 58th Street, Chicago, IL 60637.