1. Department of Mathematical Sciences Chalmers University of Technology & University of Gothenburg Gothenburg Sweden
2. University of Gothenburg Gothenburg Sweden
3. Research Institute of Industrial Economics (IFN) & Örebro University Stockholm Sweden
4. Örebro University, Örebro University School of Business, Örebro Sweden
5. Department of Economics Instituto Tecnológico Autónomo de México Mexico City Mexico