Lei Wang School of Economics, Hangzhou Normal University   Room 714, Shuyuan-1 Building Yuhangtang Road No.2318 Yuhang District Hangzhou, Zhejiang 311121 China   wangleiruc@gmail.com             JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) E5 : Monetary Policy, Central Banking, and the Supply of Money and Credit: General