Yoshitomo Okajima University of Marketing and Distribution Sciences   YOSHITOMO OKAJIMA University of Marketing and Distribution Sciences, 3-1 Gakuen-Nishimachi, Nishiku Kobe, 651-2188, 651-2188 Japan   Yoshitomo_Okajima@red.umds.ac.jp             JEL Areas: F1 : Trade: General L1 : Market Structure, Firm Strategy, and Market Performance: General