This chapter examines how the European Central Bank (ECB) has taken on new and controversial roles in relation to crisis management and financial supervision in the wake of the eurozone crisis. It also considers how the ECB’s transformation has encouraged a new wave of institutional theorizing about the Bank, placing emphasis, among other things, on the importance of credible commitments, path-dependence, strategic discourse, and the changing politics of European integration. The chapter first provides an overview of the ECB’s mandate and tasks before discussing its decision-making bodies. It then describes the ECB’s institutional design as well as its response to the euro crisis, along with various theories that explain the crisis, including historical institutionalism and the rational choice institutionalist perspective. The chapter concludes by assessing concerns about the ECB’s legitimacy.
