First Author:   Toru Hokari Faculty of Economics, Keio University hokari@econ.keio.ac.jp         Second Author: Masaki Iimura Graduate School of Humanities and Social Sciences, University of Tsukuba miimura@social.tsukuba.ac.jp         Third Author: Tatsuhiro Shichijo Department of Economics, Osaka Prefecture University shichijo@eco.osakafu-u.ac.jp