This paper examines the evolution of financial supervision as a policy tool over the last three decades, with a focus on the issues raised by the Global Crisis. It considers a sample of advanced and emerging economies to discuss the four main questions debated in the literature, and addressed in the economic policy arena: the architecture of supervision, the role of the central bank as supervisor, the governance of supervision, and financial supervision vs. the internationalization of finance. Our survey finds that, on each of these issues, theory and practice do not offer clear‐cut answers and unambiguous optimal solutions. At the same time, the most promising approach is to tackle financial supervision as a principal‐agent problem, where economics and political economy approaches must be used in combination to improve both positive and normative analyses of supervisory governance.