Why the micro-prudential regulation fails? The impact on systemic risk by imposing a capital requirement

This paper studies why the micro-prudential regulations fails to maintain a stable financial system by investigating the impact of micro-prudential regulation on the systemic risk in a cross-sectional dimension. We construct a static model for risk-taking behavior of financial institutions and compare the systemic risks in two cases with and without a capital requirement regulation. In a system with a capital requirement regulation, the individual risk-taking of the financial institutions are lower, whereas the systemic linkage within the system is higher. With a proper systemic risk measure combining both individual risks and systemic linkage, we find that, under certain circumstance, the systemic risk in a regulated system can be higher than that in a regulation-free system. We discuss a sufficient condition under which the systemic risk in a regulated system is always lower. Since the condition is based on comparing balance sheets of all institutions in the system, it can be verified only if information on risk-taking behaviors and capital structures of all institutions are available. This suggests that a macro-prudential framework is necessary for establishing banking regulations towards the stability of the financial system as a whole.