First Author:   Hikaru Ogawa Nagoya University ogawa@soec.nagoya-u.ac.jp   School of Economics, Nagoya University, Furocho Chikusaku Nagoya, 464-8601, Japan   81-52-789-2379(Phone) 81-52-789-2379(Fax) Second Author: Akira Nishimori Aichi University nisimori@vega.aichi-u.ac.jp