1. Rotman School of Management, University of Toronto, 105 St. George Street, Toronto, ON M5S 3E6, Canada and National Bureau of Economic Research (NBER) (e-mail: )
2. Rotman School of Management, University of Toronto, 105 St. George Street, Toronto, ON M5S 3E6, Canada and NBER (e-mail: )
3. Marshall School of Business, University of Southern California, 701 Exposition Blvd., HOH 503, Los Angeles, CA 90089 (e-mail: )