Eisei Ohtaki Faculty of Economics, Kanagawa university   3-27-1, Rokkakubashi, Kanagawa-ku, Yokohama-shi, Kanagawa-ken 221-8686 Japan   ohtaki@kanagawa-u.ac.jp             JEL Areas: D5 : General Equilibrium and Disequilibrium: General E0 : Macroeconomics and Monetary Economics: General