1. Department of Economics, Universidad Pública de Navarra and Institute for Advanced Research in Business and Economics, Pamplona 31006, Spain, gregori.galofre@unavarra.es
2. Department of Health Services Research and Policy, London School of Hygiene & Tropical Medicine, London WC1H 9SH, UK, martin.mckee@lshtm.ac.uk
3. Department of Social and Political Sciences, University of Bocconi, Milan 20136, Italy, david.stuckler@unibocconi.it