Lin Zhang Graduate School of Economics, Osaka University   1-7 Machikaneyama, Toyonaka, Osaka, Japan Toyonaka, Osaka 5600043 Japan   zhanglin58@gmail.com             JEL Areas: D9 : Intertemporal Choice and Growth: General E2 : Macroeconomics: Consumption, Saving, Production, Employment, and Investment: General (includes Measurement and Data)