1. a European Commission, Joint Research Centre (JRC), Institute for Prospective Technological Studies (IPTS) , Seville , Spain
2. b Department of Management and Technology , Bocconi University , via Sarfatti 25, 20136 Milano , Italy
3. c KITeS–CESPRI, Bocconi University , via Sarfatti 25, 20136 Milano , Italy
4. d ISTAT – SSI/D (Italian National Institute of Statistics) , via Tuscolana 1782, 00173 Rome , Italy
5. e ISEG/Technical University of Lisbon and UECE , rua Miguel Lupi 20, 1249–078 Lisboa , Portugal