First Author:   Masanaga Kumakura Osaka City University kumakura@cantab.net   Graduate School of Economics, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku Osaka, 558-8585, Japan   81 6 6605 2291(Phone) 81 6 6605 2291(Fax) Second Author: Masato Kuroko Institute of Developing Economies, Japan External Trade Organization masato_kuroko@ide.go.jp