Unification in financial sector supervision: The trade‐off between central bank and single authority

Abstract

The objective of this work is to analyse worldwide trends in financial supervision architectures. The focus is on the key issue in the debate – the single supervisor versus multiauthority model – in order to build up indexes of supervision unification, essential to perform studies on the causes and effects of various supervisory regimes. First, the paper introduces a Financial Authorities’ Concentration (FAC) Index. A comparative analysis of 69 countries confirmed that an increase in the degree of concentration of supervisory powers is evident in the developed countries, and particularly in the European Union. Secondly, the paper considers the nature of the institutions to which control responsibilities are entrusted. In particular, the role the central bank plays in the various national institutional settings is examined. An index of the central bank’s involvement in financial supervision is introduced, the Central Bank as Financial Authority (CBFA) Index. Each national institutional structure can be identified with the two above characteristics. Two models are the most frequent: (a) countries with a high level of unification of powers and weak central bank involvement (single financial authority regimes); and, (b) countries with a low level of unification of powers and strong central bank involvement (central bank dominated multiple supervisor regimes). A trade‐off therefore emerges between the degree of financial sector unification and the role of the central bank. Two possible explanations of this relationship emerged: the blurring hazard effect and the monopolistic bureau effect.