Yasuhiro Sakai, Emeritus Professor: Shiga University, University of Tsukuba, Department of Economics, Shiga University, [email protected], Banba 1-1-1, Hikone, Shiga, 522-8522, JapanKeisuke Sasaki, Professor, Department of Economics, Toyo University, [email protected], Hakusan 5-28-20, Bunkyouku, Tokyo, 112-8606, Japan