Kosuke Hirose Graduate School of Economics, The University of Tokyo   #202 (Matsuoka B) 5-27-5 Hongo Bunkyo(-ku), Tokyo 113-0033 Japan   h-kosuke@g.ecc.u-tokyo.ac.jp             JEL Areas: L1 : Market Structure, Firm Strategy, and Market Performance: General L0 : Industrial Organization: General