First Author:   Mengdan Li Faculty of Economics and Business, Hokkaido University Mengdannew@eis.hokudai.ac.jp   No.408, Northtown House, Kita11 Nishi3, Kita-ku Sapporo, 001-0011, Japan   81-090-6442-0520(Phone) 81-090-6442-0520(Fax)