First Author:   Sasiwimon W. Paweenawat School of Economics, University of the Thai Chamber of Commerce sasiwimon_war@utcc.ac.th   126/1 Vibhavadee-Rangsit Rd. Dindaeng, 10400, Thailand   662-6976653(Phone) 662-6976653(Fax) Second Author: Sutida Plyngam Faculty of Economics, Srinakharinwirot University sutidap@swu.ac.th   Watthana, 10110, Thailand   662-1691004(Phone)