1. Department of Economics, “G. d’Annunzio” University of Chieti-Pescara, Pescara, Italy
2. Department of Management and Business Administration, “G. d'Annunzio” University of Chieti-Pescara, Pescara, Italy
3. Department of Economics, Management and Business Law, “Aldo Moro” University of Bari, Bari, Italy