We analyze regulatory capital requirements where the amount of required capital depends on the level of risk reported by the banks. It is shown that if the supervisors have a limited ability to identify or to sanction dishonest banks, an additional, risk-independent leverage ratio restriction may be necessary to induce truthful risk reporting. The leverage ratio helps to offset the banks’ potential capital savings of understating their risks by (i) reducing banks’ put option value of limited liability ex ante, and by (ii) increasing the banks’ net worth, which in turn enhances the supervisors’ ability to sanction banks ex post.

The present paper demonstrates the ambiguous impact of subordinated debt on the risk-taking incentives of banks. It is shown that in comparison with full deposit insurance, subordinated debt reduces risk only if banks can credibly commit to a given level of risk. If, however, banks are not able to commit, subordinated debt leads to an increase in risk. This is because due to limited liability banks always have an incentive to increase their risk after the interest rate is contracted in order to reduce the expected costs of debt. Rational debt holders anticipate this behavior and accordingly require a higher risk premium ex ante. The higher interest rates in turn further aggravate the excessive risk-taking incentives of banks.