1. Institute of Development Research and Development Policy, Ruhr-University Bochum, 44805 Bochum, Germany
2. Centre for Studies on European Economy, Azerbaijan State University of Economics (UNEC), Baku AZ1001, Azerbaijan
3. College of Business and Public Management, Wenzhou-Kean University, Wenzhou 352060, China
4. Department of Economic and Statistical Sciences, University of Salerno, 84084 Fisciano, Italy