Takanori Minamikawa Economic Research Institute for Northeast Asia   13th Floor, Bandaijima Building, Bandaijima 5-1, Chuo-ku, Niigata City, Niigata 950-0078 Japan   minamikawa.takanori.60@erina.or.jp             JEL Areas: B4 : Economic Methodology: General C1 : Econometric and Statistical Methods: General