Supervisory models evolve with financial markets. To address the evolution of financial markets and institutions, new supervisory structures have been developed. This chapter analyzes systemic supervision under the integrated, functional, and Twin Peaks models, and systemic composite bodies to elucidate their strengths and weaknesses when managing financial stability. Models examined cover those in Hong Kong, Mainland China, the United States, United Kingdom, Singapore, Australia, South Africa, and the Netherlands. Systemic oversight between traditional central banks and integrated micro-prudential supervisors is subject to supervisory underlap. This was the core weakness of the United Kingdom’s integrated model and is a regulatory flaw inherent to the institutional, sectoral, and functional models. Composite systemic bodies are imperative for supervisory models consisting of central banks that are not unified with prudential supervisors or divided among multiple supervisors. The Twin Peaks model does not need a composite systemic body because this is the role of the systemic peak supervisor. Neither does a unified fully integrated supervisor because the role is internalized. However, competing objectives within a fully integrated supervisor can produce bias and conflicts, eroding systemic supervision and financial stability.

In the wake of the 2008–9 global financial crisis, the G20 devised a framework for a sustainable recovery based on international cooperation. An agreement was reached to ensure that inter alia macro-prudential and regulatory policies would support sustainable economies by preventing credit and asset price cycles from becoming forces for financial destabilization. The G20 recognized the importance of striking a balance between micro- and macro-prudential regulation to control risks, and to develop tools to monitor the build-up of systemic risk in the financial system. This chapter argues that the design of the supervisory structure is instrumental in striking the appropriate balance between these regulatory disciplines. Clear mandates and supervisory judgement are necessary to control this interdependent relationship. Regulatory underlap, gaps, and arbitrage can surface when the supervisory structure does not harmonize with legal infrastructure. To mitigate these regulatory flaws causing financial instability and producing unsustainable economies, supervisors must have sufficient capacity, expertise, awareness, and discretion. Attaining financial stability and a sustainable economy requires the supervisory structure or model, and the supervisor’s capacity and expertise to be harmonized with the legal infrastructure.