1. Center for Economic and Social Research, University of Southern California, 635 Downey Way, Suite 312, Dauterive Hall, Los Angeles, CA 90089 (e-mail: )
2. Department of Economics and Business, Gordon College, 255 Grapevine Road, Wenham, MA 01984 (e-mail: )
3. Samuel Curtis Johnson Graduate School of Management, Cornell University, 324 Sage Hall, Ithaca, NY 14853, and Department of Economics, Hebrew University of Jerusalem (e-mail: )
4. Department of Economics, University of Colorado Boulder, 256 UCB, Boulder, CO, 80309 (e-mail: )