Measuring portfolio credit risk correctly: why parameter uncertainty matters
AbstractWhy should risk management systems account for parameter uncertainty? In order to answer this question, this paper lets an investor in a credit portfolio face non-diversifiable estimation-driven uncertainty about two parameters: probability of default and asset-return correlation. Bayesian inference reveals that - for realistic assumptions about the portfolio's credit quality and the data underlying parameter estimates - this uncertainty substantially increases the tail risk perceived by the investor. Since incorporating parameter uncertainty in a measure of tail risk is computationally demanding, the paper also derives and analyzes a closed-form approximation to such a measure.
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Bibliographic InfoPaper provided by Bank for International Settlements in its series BIS Working Papers with number 280.
Length: 43 pages
Date of creation: Apr 2009
Date of revision:
correlated defaults; estimation error; risk management;
Other versions of this item:
- Tarashev, Nikola, 2010. "Measuring portfolio credit risk correctly: Why parameter uncertainty matters," Journal of Banking & Finance, Elsevier, vol. 34(9), pages 2065-2076, September.
- NEP-ALL-2009-04-25 (All new papers)
- NEP-BAN-2009-04-25 (Banking)
- NEP-RMG-2009-04-25 (Risk Management)
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- Gordy, Michael B., 2003.
"A risk-factor model foundation for ratings-based bank capital rules,"
Journal of Financial Intermediation,
Elsevier, vol. 12(3), pages 199-232, July.
- Michael B. Gordy, 2002. "A risk-factor model foundation for ratings-based bank capital rules," Finance and Economics Discussion Series 2002-55, Board of Governors of the Federal Reserve System (U.S.).
- Zhu, Haibin & Tarashev, Nikola A., 2008. "The pricing of correlated default risk: evidence from the credit derivatives market," Discussion Paper Series 2: Banking and Financial Studies 2008,09, Deutsche Bundesbank, Research Centre.
- Bongaerts, Dion & Charlier, Erwin, 2009.
"Private equity and regulatory capital,"
Journal of Banking & Finance,
Elsevier, vol. 33(7), pages 1211-1220, July.
- Hanson, Samuel & Schuermann, Til, 2006. "Confidence intervals for probabilities of default," Journal of Banking & Finance, Elsevier, vol. 30(8), pages 2281-2301, August.
- Merton, Robert C, 1974.
"On the Pricing of Corporate Debt: The Risk Structure of Interest Rates,"
Journal of Finance,
American Finance Association, vol. 29(2), pages 449-70, May.
- Merton, Robert C., 1973. "On the pricing of corporate debt: the risk structure of interest rates," Working papers 684-73., Massachusetts Institute of Technology (MIT), Sloan School of Management.
- Lütkebohmert, Eva & Gordy, Michael B., 2007. "Granularity adjustment for Basel II," Discussion Paper Series 2: Banking and Financial Studies 2007,01, Deutsche Bundesbank, Research Centre.
- Forte, Santiago & Peña, Juan Ignacio, 2009. "Credit spreads: An empirical analysis on the informational content of stocks, bonds, and CDS," Journal of Banking & Finance, Elsevier, vol. 33(11), pages 2013-2025, November.
- Borio, Claudio & Tsatsaronis, Kostas, 2004. "Accounting and prudential regulation: from uncomfortable bedfellows to perfect partners?," Journal of Financial Stability, Elsevier, vol. 1(1), pages 111-135, September.
- Kerkhof, Jeroen & Melenberg, Bertrand & Schumacher, Hans, 2010. "Model risk and capital reserves," Journal of Banking & Finance, Elsevier, vol. 34(1), pages 267-279, January.
- Lando, David & Skodeberg, Torben M., 2002. "Analyzing rating transitions and rating drift with continuous observations," Journal of Banking & Finance, Elsevier, vol. 26(2-3), pages 423-444, March.
- Chollete, Lorán & de la Peña, Victor & Lu, Ching-Chih, 2012. "International diversification: An extreme value approach," Journal of Banking & Finance, Elsevier, vol. 36(3), pages 871-885.
- Pflug, Georg Ch. & Pichler, Alois & Wozabal, David, 2012. "The 1/N investment strategy is optimal under high model ambiguity," Journal of Banking & Finance, Elsevier, vol. 36(2), pages 410-417.
- Chollete, Lorán & de la Peña, Victor & Lu, Ching-Chih, 2011. "International diversification: A copula approach," Journal of Banking & Finance, Elsevier, vol. 35(2), pages 403-417, February.
- Aussenegg, Wolfgang & Resch, Florian & Winkler, Gerhard, 2011. "Pitfalls and remedies in testing the calibration quality of rating systems," Journal of Banking & Finance, Elsevier, vol. 35(3), pages 698-708, March.
- Henry Dannenberg, 2011. "The Importance of Estimation Uncertainty in a Multi-Rating Class Loan Portfolio," IWH Discussion Papers 11, Halle Institute for Economic Research.
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