[1] Univ Padua, Dept Econ & Business, Via Santo 33, I-35123 Padua, Italy
[2] Univ Padua, Dept Econ & Management, Padua, Italy
[3] UCL, Ctr Organisat Network Anal, Bartlett Sch Construct & Project Management, London, England
[4] Univ Toronto, Geog & Planning, Toronto, ON, Canada