[1] Metropolia Univ Appl Sci, Helsinki, Finland
[2] Aalto Univ, Dept Ind Engn & Management, Espoo, Finland
[3] Swiss Fed Inst Technol, Dept Management Technol & Econ, Swiss Fed Inst Technol Zurich, Zurich, Switzerland
[4] Harvard Univ, Dept Sociol, Cambridge, MA 02138 USA