1. Department of Economics, University of Messina, Piazza Pugliatti, 198122 Messina, Italy
2. Department of Economic and Mathematical Modelling, Faculty of Economics, Peoples’ University of Russia (RUDN University), Miluh-Maklaya, 6, 117519 Moscow, Russia
3. V.A. Trapeznikov Institute of Control Sciences, Russian Academy of Sciences, Profsoyznaya, 65, 117997 Moscow, Russia