Youngho Chang Nanyang Technological University, Singapore   School of Humanities and Social Sciences School of Humanities and Social Sciences Nanyang Technological University Singapore, Singapore 639798 Singapore   isyhchang@ntu.edu.sg   http://www.hssapps.ntu.edu.sg/faculty/econ.asp?u=isyhchang           JEL Areas: Q : Agricultural and Natural Resource Economics Q4 : Energy: General