Ikeda Yasuhiro Kumamoto University, Faculty of Law   2-40-1 Kurokami, Chuou-ku Kumamoto University, Faculty of Law Kumamoto-shi, Kumamoto 860-8555 Japan   ikeyasu@kumamoto-u.ac.jp             JEL Areas: L1 : Market Structure, Firm Strategy, and Market Performance: General L3 : Nonprofit Organizations and Public Enterprise: General