1. School of International Trade and Economics, Central University of Finance and Economics, Beijing, People’s Republic of China
2. Faculty of Economics and Business, University of Groningen, Groningen, Netherlands
3. School of Economics, Capital University of Economics and Business, Beijing, People’s Republic of China
4. Academy of Mathematics and Systems Science, China Academy of Sciences, Beijing, People’s Republic of China
5. School of Economics and Management, University of Chinese Academy of Sciences, Beijing, People’s Republic of China