Tuesday, December 16, 2014

Basel III Leverage Ratio Requirement and the Probability of Bank Runs

DERMINE Jean
Basel III Leverage Ratio Requirement and the Probability of Bank Runs Journal of Banking and Finance (forthcoming)

A new argument for the Basel III leverage ratio requirement is proposed: the need to limit the risk of a bank run when there is imperfect information on the value of a bank’s assets. In addition to screening and monitoring borrowers, banks provide liquidity insurance with the supply of short-term deposits withdrawable on demand. The maturity mismatch creates the risk of a disorderly bank run which can be exacerbated by imperfect information about the value of bank assets. It is shown in a stylized Basel III framework that capital regulation should incorporate a liquidity risk component. Credit risk diversification and/or a reduced probability of loan default which lead to a reduction of Basel III regulatory capital will increase the probability of a bank run. The leverage ratio rule puts a floor on the Basel III risk-weighed capital ratio, allowing the limitation of such a risk.