First Author:   Hideaki Sakawa Graduate School of Economics, Nagoya City University sakawa@econ.nagoya-cu.ac.jp   1 Yamanohata, Mizuho-cho, Mizuho-ku Nagoya, 4678501, Japan   +81-52-872-5724(Phone) +81-52-872-5724(Fax) Second Author: Masato Ubukata Kushiro Public University of Economics ubukata@kushiro-pu.ac.jp   Ashino, Ashino Kushiro, 0858585, Japan   +81-154-37-3210(Phone) +81-154-37-3287(Fax)