1. Jinhe Center for Economic Research, Xi’an Jiaotong University, 28, Xianning West Road, Beilin District, Xi’an City, P. R. China
2. Institute of Economics, Academia Sinica, 128, Section 2, Academia Road, Nangang, Taipei, Taiwan
3. Research Center for Environmental Changes, Academia Sinica, 128, Section 2, Academia Road, Nangang, Taipei, Taiwan