Affiliation: | aThe School of Management, Tokyo University of Science, 500 Shimokiyoku, Kuki-shi, Saitama 346-8512, Japan;bGraduate School of Economics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan;cThe Institute of Social and Economic Research, Osaka University, 6-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan |