1. Department of Social and Economic Geography, Uppsala University, PO Box 513, 751 20 Uppsala, Sweden
2. Department of Human and Economic Geography, Lund University, Sölvegatan 12, 223 62 Lund, Sweden; and Centre for Innovation, Research and Competence in the Learning Economy (CIRCLE), Lund University, Sölvegatan 16, 22100 Lund, Sweden