First Author:   Akihiko Noda Graduate School of Business and Commerce, Keio University noda@2007.jukuin.keio.ac.jp   2-15-45 Mita Minato-ku, 108-8345, Japan       http://at-noda.com/ Second Author: Shunsuke Sugiyama Graduate School of Economics, Keio University sugiyama@gs.econ.keio.ac.jp   Minato-ku, 108-8345, Japan       http://sugi-shun.com/