1. Reinhard Busse ( ) is a professor in and head of the Department of Health Care Management, a World Health Organization Collaborating Center for Health Systems Research and Management, at the Technische Universität Berlin, in Germany.
2. Juliane Stahl was a research fellow in the Department of Health Care Management at the Technische Universität Berlin at the time of this study. She is now a research fellow at the German Institute for Economic Research, in Berlin.