Jeerawadee Pumjaroen Rajamangala University of Technology Thanyaburi (RMUTT)   Applied Statistics Rajamangala University of Technology Thanyaburi , Pathum Thani 12110 Thailand   jeerawadee_p@rmutt.ac.th             JEL Areas: E3 : Prices, Business Fluctuations, and Cycles: General (includes Measurement and Data) D5 : General Equilibrium and Disequilibrium: General