First Author:   Alessia Lo Turco Polytechnic University of Marche a.loturco@univpm.it   Department of Economics, Faculty of Economics "Giorgio Fuà", Piazzale Martelli 8 Ancona, 60121, Italy   +390712207250(Phone) +390712207250(Fax) http://www.univpm.it/alessia.lo.turco Second Author: Aleksandra Parteka Gdansk University of Technology aparteka@zie.pg.gda.pl   ul. Narutowicza 11/12 , 80-952, Poland   347-18-99(Phone) 347-18-61(Fax)