Nathapornpan Uttama Economics Program, School of Management, Mae Fah Luang University   333 Moo 1, Tasud Muang, Chiang Rai 57100 Thailand   nathapornpan@mfu.ac.th   mfu.ac.th           JEL Areas: G2 : Financial Institutions and Services: General D4 : Market Structure and Pricing: General