1. Department of Health Management and Health Economics, University of Oslo, Oslo, Norway
2. Division of Health Services, Norwegian Institute of Public Health, Oslo, Norway
3. Centre for Health Economics, University of York, York, UK
4. Department of Economics and Related Studies, University of York, York, UK
5. School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
6. School of Social and Community Medicine, University of Bristol, Bristol, UK
7. Health Services Research Unit, Akershus University Hospital, Oslo, Norway
8. Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Canada
9. Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
10. Department of Statistical Science, University College London, London, UK