Yanfeng Wei Graduate School of Social Sciences, Hiroshima University, Japan   Graduate School of Social Sciences Hiroshima University Japan Higashi-Hiroshima, Hiroshima 739-8525 Japan   weiyanfeng@hiroshima-u.ac.jp             JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) C3 : Multiple or Simultaneous Equation Models: General