Bruno Marchal is associate professor and co-head of the Health Systems and Equity unit, Department of Public Health, Institute of Tropical Medicine, Antwerp (Belgium). He is a visiting researcher at the School of Public Health, University of the Western Cape, Cape Town. Bruno currently works mainly on governance and stewardship at local health system level, urban health and research methodologies for complex issues in health. Much of his work adopts the realist approach to the field of health policy and systems research in low- and middle-income countries.