Johanna Hanefeld1, Aaron Reeves2, Chris Brown3, Piroska Östlin4. 1. London School of Hygiene & Tropical Medicine, London WC1H 9SH, UK. Electronic address: johanna.hanefeld@lshtm.ac.uk. 2. Department of Social Policy and Intervention, University of Oxford, Oxford, UK. 3. WHO Office for Investment for Health and Development, Venice, Italy. 4. WHO Regional Office for Europe, Copenhagen, Denmark.