1. Asian Growth Research Institute, 11-4 Otemachi, Kokura-kita, Kitakyushu, Fukuoka 803-0814, Japan
2. National Bureau of Economic Research, 1050 Massachusetts Ave., Cambridge, MA 02138, USA
3. Institute of Social and Economic Research, Osaka University, 6-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan