1. Center for Energy and Environmental Policy Research, Beijing Institute of Technology, Beijing, People’s Republic of China
2. School of Management and Economics, Beijing Institute of Technology, Beijing, People’s Republic of China
3. Faculty of Business, Multimedia University Malaysia, Melaka, Malaysia
4. Department of Economics, Faculty of Business & Economics, Abdul Wali Khan University Mardan-KP, Mardan, Pakistan
5. Rajagiri Business School, Kochi, India