1 Cristina Hernández-Quevedo is with the European Observatory on Health Systems and Policies, London School of Economics and Political Science, London, England. Beatriz G. Lopez-Valcarcel is with the Department of Quantitative Methods for Economics & Management, University of Las Palmas de Gran Canaria, Canary Islands, Spain. Miquel Porta is with the Hospital del Mar Institute of Medical Research (IMIM), Universitat Autònoma de Barcelona, CIBER de Epidemiología y Salud Pública, Barcelona, Spain, and the Gillings School of Global Public Health, University of North Carolina, Chapel Hill.