1. School of Economics, Fujian Normal University, Fuzhou, Fujian 350117, China
2. Applied Economics Department, College of Economics and Management, Beijing University of Technology, Beijing 100124, China
3. Xi’an University of Finance and Economics, Xi'an, Shaanxi 710100, China
4. School of Economics, Collaborative Innovation Research Center of Western Energy Economy and Regional Development, Xi’an University of Finance and Economics, Xi'an, Shaanxi 710100, China
5. School of Economics and Trade, Hunan University, Changsha 410079, China