The link between default and recovery rates: effects on the procyclicality of regulatory capital ratios

This paper analyses the impact of various assumptions about the association between aggregate default probabilities and the loss given default on bank loans and corporate bonds, and seeks to empirically explain this critical relationship. Moreover, it simulates the effects of this relationship on the procyclicality of mandatory capital requirements like those proposed in 2001 by the Basel Committee on Banking Supervision. We present the analysis and results in four distinct sections. The first section examines the literature of the last three decades of the various structural-form, closed-form and other credit risk and portfolio credit value-at-risk (VaR) models and the way they explicitly or implicitly treat the recovery rate variable. Section 2 presents simulation results under three different recovery rate scenarios and examines the impact of these scenarios on the resulting risk measures: our results show a significant increase in both expected an unexpected losses when recovery rates are stochastic and and negatively correlated with default probabilities. In Section 3, we empirically examine the recovery rates on corporate bond defaults, over the period 1982-2000. We attempt to explain recovery rates by specifying a rather straightforward statistical least squares regression model. The central thesis is that aggregate recovery rates are basically a function of supply and demand for the securities. Our econometric univariate and multivariate time series models explain a significant portion of the variance in bond recovery rates aggregated across all seniority and collateral levels. Finally, in Section 4 we analyse how the link between default probability and recovery risk would affect the procyclicality effects of the New Basel Capital Accord, due to be released in 2002. We see that, if banks are let free to use their own estimates of LGD (as in the "advanced" IRB approach), an increase in their sensitivity to economic cycles would follow. Our results have important implications for just about all portfolio credit risk models, for markets which depend on recovery rates as a key variable (eg securitisations, credit derivatives, etc), for the current debate on the revised BIS guidelines for capital requirements on bank credit assets, and for investors in corporate bonds of all credit qualities.

This paper was presented at the conference on "Changes in risk through time: measurement and policy responses" organised by the BIS on 6 March 2002 and, as such, is appearing in the BIS Working Papers series.