1. School of Economics, Southwestern University of Finance and Economics, Chengdu 611130, China
2. School of Economics and Business Administration, Chongqing University of Education, Chongqing 400065, China
3. Centre for Policy Research, Universiti Sains Malaysia, Gelugor 11800, Penang, Malaysia
4. Institute of Western China Economic Research, Southwestern University of Finance and Economics, Chengdu 611130, China