First Author:   Yuncheol Jeong Faculty of Business and Commerce, Keio University jeongyc@fbc.keio.ac.jp   2-15-45, Mita, Minato-ku Tokyo, 108-8345, Japan   +81 3 5427 1082(Phone) +81 3 5427 1082(Fax) Second Author: Masayoshi Maruyama Graduate School of Business Administration, Kobe University mmaru@kobe-u.ac.jp   2-1, Rokkodai, Nada-ku Kobe, 657-8501, Japan   +81 78 803 694(Phone) +81 78 803 694(Fax)