Associate professor Jochen Mierau’s background is in economics, but as a founding member of the Aletta Jacobs School of Public Health, he is applying his expertise to a new discipline. Health outcomes vary from one nation to the next, but zooming in on the level of neighbourhoods can shed light on best practices that can be applied on a city or regional level. Mierau says that public health is not a spectator sport, and in our conversation about the increasingly interdisciplinary nature of this academic field, in honour of the school’s namesake, he talks about how health care interventions effectively amount to a form of activism.