1. School of Economics, University of New South Wales, Sydney, NSW 2052, Australia, Department of Economics, Michigan State University, and School of Economics, Yonsei University (e-mail: )
2. Toulouse School of Economics (GREMAQ, IDEI), Manufacture de Tabacs, 21 Allée de Brienne, 31000, Toulouse, France and Department of Economics, Sungkyunkwan University, 53 Myungryun-Dong 3 Ga, Jongro-Gu, Seoul, Korea 110-745 (e-mail: )
3. School of Economics, Georgia Institute of Technology, 221 Bobby Dodd Way, Atlanta, GA 30332 (e-mail: )