Toshihiro Tsuchihashi Daito Bunka University   1-9-1 Takashimadaira, Tokyo, Japan, 175-8571 Itabashi, Tokyo 17-8571 日本   tsuchihasi@ic.daito.ac.jp             JEL Areas: C7 : Game Theory and Bargaining Theory:General D4 : Market Structure and Pricing: General