First Author:   Keiichiro Kobayashi Research Institute of Economy, Trade, and Industry kobayashi-keiichiro@rieti.go.jp   11th floor, Annex, Ministry of Economy, Trade and Industry, 1-3-1, Kasumigaseki, Chiyoda-ku, Tokyo, 100-8901, Japan       Second Author: Kengo Nutahara Graduate School of Economics, University of Tokyo, and the JSPS Research Fellow ee67003@mail.ecc.u-tokyo.ac.jp   Akamon General Research Building 4th Floor Room 433,, Graduate School of Economics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan       http://kengo.nutahara.googlepages.com/