Hierarchy, polyarchy, and experimentalism in EU banking regulation: the Single Supervisory Mechanism in action

ABSTRACT This paper analyzes the Single Supervisory Mechanism (SSM) from three overlapping perspectives: first, as a centralized hierarchy, seeking to enforce uniform rules, standards, and procedures; second, as a polyarchic network, seeking to orchestrate cooperation between the ECB and national authorities; and finally, as an experimentalist organization, seeking to learn from diversity by adapting common rules and procedures to the specificities of individual banks, and revising them regularly through peer review of implementation experience at multiple levels. Drawing extensively on interviews and primary documents, the paper traces the evolution of the SSM’s institutional structures, decision-making processes, and organizational practices from its origins to the present. On this basis, the paper argues that the most encompassing perspective on the SSM is that of an experimentalist organization, which integrates and recasts key elements of the other two views into a more complete and dynamic analysis of its evolving architecture and practical operations.