1. Paul J. Boyle, School of Geography and Geosciences, University of St. Andrews, St. Andrews, KY16 9AL, United Kingdom
2. Max Planck Institute for Demographic Research, Rostock, Germany
3. Department of Geography, University of Connecticut, Storrs, United States
4. Department of Applied Social Science, University of Stirling, Stirling, United Kingdom
5. Department of Geography, Planning and International Development Studies, University of Amsterdam, The Netherlands