Kate Raworth’s doughnut model is an economic theory designed to easily and intelligibly assess an economy’s sustainability. Visually represented in the shape of a doughnut, it combines the concepts of planetary boundaries and minimum social standards to measure economic performance. Major European cities such as Amsterdam, Geneva and Brussels, have adopted the doughnut model to guide their green transitions. Barbara Trachte, secretary of state of the Brussels-Capital Region, responsible for Economic Transition and Scientific Research, explains how Brussels is using the the model to set a new direction for the city region’s economy.