1. European Central Bank; Directorate General Economics; Kaiserstraße 29 D-60311 Frankfurt am Main Germany
2. Department of Economics; UECE-Research Unit on Complexity and Economics; ISEG-Technical University of Lisbon; R. Miguel Lupi 20 1249-078 Lisbon Portugal
3. Cardiff Business School; Cardiff University; Cardiff CF10 3EU UK
4. Accounting and Finance Subject; Adam Smith Business School, University of Glasgow; Glasgow G12 8QQ UK