Takeshi Ogawa School of Economics, Senshu University   Hiroshima, Hiroshima 733-0011 Japan   takeshi.ogawa.123@gmail.com   https://shu-lab.shudo-u.ac.jp/profile/en.8K7tCRngiY1UjgEmyPB-ow==.html           JEL Areas: F1 : Trade: General D2 : Production and Organizations: General