Countercyclical capital buffers: exploring options

This paper provides some general lessons for the design of countercyclical capital buffers. Its main empirical contribution is to analyse conditioning variables which could guide the build-up and release of capital. A major distinction for countercyclical capital schemes is whether conditioning variables are bank-specific or system-wide. The evidence presented in the paper indicates that the idiosyncratic component can be sizeable when a bank-specific approach is used. This makes a system-wide approach preferable, for which the best variables as signal for the pace and size of the accumulation of the buffers are not necessarily the best for the timing and intensity of the release. The credit-to-GDP ratio seems best for the build-up phase. Some measure of aggregate losses, possibly combined with indicators of credit conditions, seem to perform well for signalling the beginning of the release phase. Nonetheless, the analysis indicates that designing a fully rule-based mechanism may not be possible at this stage as some degree of judgment seems inevitable. A parallel exercise indicates that reducing the sensitivity of the minimum capital requirement is an important element of a credible countercyclical buffer scheme.