Kojun Hamada Faculty of Economics, Niigata University   Faculty of Economic Sciences, Niigata University 8050 Ikarashi 2-no-cho, Nishi-ku Niigata, Niigata 950-2181 Japan   khamada@econ.niigata-u.ac.jp             JEL Areas: D2 : Production and Organizations: General L2 : Firm Objectives, Organization, and Behavior: General