[1] York Univ, Dept Math & Stat, Toronto, ON M3J 1P3, Canada
[2] Polo Tecnol IISS G Galilei, I-39100 Bolzano, Italy
[3] Univ Complutense Madrid, Dept Econ Aplicada 2, Pozuelo 28223, Spain
[4] Univ Complutense Madrid, Inst Complutense Estudios Internac, Pozuelo 28223, Spain
[5] La Salle Univ, Business Syst & Analyt Dept, Lindback Distinguished Chair Informat Syst & Deci, Philadelphia, PA 19141 USA
[6] Univ Paderborn, Fac Business Adm & Econ, Business Informat Syst Dept, D-33098 Paderborn, Germany