Nora Gottlieb1, Kayvan Bozorgmehr2, Ursula Trummer3, Bernd Rechel4. 1. Department of Health Care Management, Technical University Berlin, Berlin, Germany. Electronic address: nora.gottlieb@tu-berlin.de. 2. Department of Population Medicine and Health Services Research, School of Public Health, Bielefeld University, Germany; Department of General Practice & Health Services Research, Social Determinants, Equity & Migration Group, Heidelberg University Hospital, Heidelberg, Germany. 3. Center for Health and Migration, Vienna, Austria. 4. European Observatory on Health Systems and Policies, London School of Hygiene & Tropical Medicine, London, United Kingdom.