Dongya Koh University of Arkansas   1 University of Arkansas Business Building 402 Fayetteville, AR 72701 USA   dkoh@walton.uark.edu   https://sites.google.com/site/dongyakoh/           JEL Areas: C6 : Mathematical Methods and Programming: General E2 : Macroeconomics: Consumption, Saving, Production, Employment, and Investment: General (includes Measurement and Data)