First Author:   Kuo I Chang The University of Tokyo aa57090@mail.ecc.u-tokyo.ac.jp   7B538R, Yayoi 1-1-1 , Bunkyo-Ku, Tokyo 113-8657, Japan Tokyo, 113-8657, Japan   81-3-58418145(Phone) 81-3-58418145(Fax) Second Author: Kazunobu Hayakawa Keio University hayakawa@gs.econ.keio.ac.jp   Mita2-15-45, Minato-ku, Tokyo 108-8345, Japan Tokyo, 108-8345, Japan   81-3-9022402158(Phone)