1Luuk P.A. Simons is Part‐time Researcher in the Department of Technology, Policy and Management at Delft Technical University, Delft, and a Senior Consultant at KPN Research, The Hague, The Netherlands.
2Charles Steinfield is a Professor in the Department of Telecommunication at Michigan State University, East Lansing, Michigan, USA.
3Harry Bouwman is a Senior Lecturer in the Department of Technology, Policy and Management at Delft Technical University, Delft, The Netherlands.