A Risk-factor Model Foundation for Ratings-based Bank Capital Rules

DefaultRisk.com the web's biggest credit risk modeling resource.

Submit Your Paper

Fitch Ratings Jobs

[ Worldwide]

Post Your Résumé
For Recruiters

Featured Book

Paris-Princeton Lectures on Mathematical Finance 2004 Finance 2004
by Rene A. Carmona, Ivar Ekeland, Arturo Kohatsu-Higa, Jean-Michel Lasry, Pierre-Louis Lions, Huyen Pham, Erik Taflin, Springer, (October 1, 2007), Paperback, 248 pages

Training Discounted for DefaultRisk.com visitors only:

The Mathematics of Credit Derivatives: The Essential Credit Modelling and Pricing Companion
by Philipp J. Schönbucher,
WBS Training, August 2003, DVD / Interactive CD-ROM

Sponsor:
Shop at Amazon.com and support DefaultRisk.com

Gordy, Michael B., "A Risk-factor Model Foundation for Ratings-based Bank Capital Rules", Journal of Financial Intermediation, Vol. 12, No. 3, (July 2003), pp. 199-232.

Abstract: I demonstrate that ratings-based capital rules, including both the current Basel Accord and its proposed revision, can be reconciled with the general class of credit value-at-risk models. Each exposure's contribution to VaR is portfolio-invariant only if (a) dependence across exposures is driven by a single systematic risk factor, and (b) no exposure accounts for more than an arbitrarily small share of total portfolio exposure. Analysis of rates of convergence to asymptotic VaR leads to a simple and accurate portfolio-level add-on charge for undiversified idiosyncratic risk. There is no similarly simple way to address violation of the single factor assumption.

JEL Classification: G31, G38.

Keywords: Capital allocation, Banking regulation, Value-at-Risk.

Books Referenced in this Paper: (what is this?)