• agent-based computational economics
• Basel III regulation
• capi
• macroprudential policy

After the destructive impact of the global financial crisis of 2008, many believe that pre-crisis financial market regulation did not take the “big picture” of the system sufficiently into account
and, subsequently, financial supervision mainly “missed the forest for the trees”. As a result, the need for macroprudential aspects of regulation emerged, which has recently become the focal point of many policy debates. This has also led to intense discussion on the contours of monetary policy after the post-crisis “new normal”. Here, we review recent progress in empirical and theoretical research on the effectiveness of macroprudential tools, as well as the current state of the debate, in order to extract common policy conclusions. The work highlights that, despite the achievements in the literature, the current experience and knowledge of how macroprudential instruments work, their calibration, and the mechanisms through which they interact with each other and with monetary policy are rather limited and conflicting. Moreover, we critically survey and note the current challenges faced by macroprudential regulation in creating stable, yet efficient financial systems. At the same time, we emphasize the importance of accepting that many risks may remain, requiring that we proceed prudently and develop better plans for future crises. As a support to survey we develop an agent-based model to study the macroeconomic impact of alternative macro-prudential regulations and their possible interactions with different monetary policy rules. The aim is to shed light on the most appropriate policy mix to achieve the resilience of the banking sector and foster macroeconomic stability. Simulation results show that a triple-mandate Taylor rule, focused on output gap, inflation and credit growth, and a Basel III prudential regulation is the best policy mix to improve the stability of the banking sector and smooth output fluctuations. Moreover, we consider the different levers of Basel III and their combinations. We find that minimum capital requirements and counter-cyclical capital buffers allow to achieve results close to the Basel III first-best with a much more simplified regulatory framework. Finally, the components of Basel III are non-additive: the inclusion of an additional lever does not always improve the performance of the macro-prudential regulation.