1 Lecturer, Faculty of Economics, Thammasat University. The author is grateful for Dr. Praipol Koomsup’s
and Dr. Archanun Kohpaiboon’s generous guidance and Ms. Roongthip Srisethkul’s helpful remarks. Anonymous
comments are also acknowledged. All errors remain author’s. This paper was awarded consolation prize for Bank of
Thailand’s Settatas – Economic Article Contest in 2011.