First Author:   Akihiro Kawase Faculty of Economics, Toyo University kawase@toyonet.toyo.ac.jp   5-28-20, Hakusan Bunkyo-ku, 112-8606, Japan   +81-3-3945-7109(Phone) +81-3-3945-7109(Fax) Second Author: Katsuyoshi Nakazawa Faculty of Economics, Toyo University nakazawa@toyonet.toyo.ac.jp