CDO rating methodology: Some thoughts on model risk and its implications
AbstractRating collateralised debt obligations (CDOs), which are based on tranched pools of credit risk exposures, does not only require attributing a probability of default to each obligor within the portfolio. It also involves assumptions concerning recovery rates and correlated defaults of pool assets, thus combining credit risk assessments of individual collateral assets with estimates about default correlations and other modelling assumptions. In this paper, we explain one of the most well-known models for rating CDOs, the so-called binomial expansion technique (BET). Comparing this approach with an alternative methodology based on Monte Carlo simulation, we then highlight the potential importance of correlation assumptions for the ratings of senior CDO tranches and explore what differences in methodologies across rating agencies may mean for senior tranche rating outcomes. The remainder of the paper talks about potential implications of certain model assumptions for ratings accuracy, that is the "model risk" taken by investors when acquiring CDO tranches, and whether and under what conditions methodological differences may generate incentives for issuers to strategically select rating agencies to get particular CDO structures rated.
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Bibliographic InfoPaper provided by Bank for International Settlements in its series BIS Working Papers with number 163.
Length: 31 pages
Date of creation: Nov 2004
Date of revision:
Collateralised debt obligations; credit risk modelling; rating agencies;
Find related papers by JEL classification:
- C15 - Mathematical and Quantitative Methods - - Econometric and Statistical Methods and Methodology: General - - - Statistical Simulation Methods: General
- G11 - Financial Economics - - General Financial Markets - - - Portfolio Choice; Investment Decisions
- G15 - Financial Economics - - General Financial Markets - - - International Financial Markets
- G20 - Financial Economics - - Financial Institutions and Services - - - General
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- Scholz, Julia, 2011. "Manager- und transaktionsspezifische Determinanten der Performance von Arbitrage CLOs," Discussion Papers in Business Administration 12144, University of Munich, Munich School of Management.
- Gann, Philipp, 2009. "Liquidität, Risikoeinstellung des Kapitalmarktes und Konjunkturerwartung als Preisdeterminanten von Collateralized Debt Obligations (CDOs) - Eine simulationsgestützte Analyse," Discussion Papers in Business Administration 10582, University of Munich, Munich School of Management.
- Efraim Benmelech & Jennifer Dlugosz, 2009.
"The Credit Rating Crisis,"
NBER Working Papers
15045, National Bureau of Economic Research, Inc.
- Roberts, John & Jones, Megan, 2009. "Accounting for self interest in the credit crisis," Accounting, Organizations and Society, Elsevier, vol. 34(6-7), pages 856-867, August.
- Li L. Ong & Jorge A. Chan-Lau, 2006. "The Credit Risk Transfer Market and Stability Implications for U.K. Financial Institutions," IMF Working Papers 06/139, International Monetary Fund.
- Ingo Fender & Janet Mitchell, 2005.
"Structured finance : complexity, risk and the use of ratings,"
Financial Stability Review,
National Bank of Belgium, vol. 3(1), pages 127-135, June.
- Ingo Fender & Janet Mitchell, 2005. "Structured finance: complexity, risk and the use of ratings," BIS Quarterly Review, Bank for International Settlements, June.
- Byström, Hans, 2006.
"The Microfinance Collateralized Debt Obligation: a Modern Robin Hood?,"
2006:14, Lund University, Department of Economics, revised 21 Aug 2006.
- Byström, Hans N.E., 2008. "The Microfinance Collateralized Debt Obligation: A Modern Robin Hood?," World Development, Elsevier, vol. 36(11), pages 2109-2126, November.
- François-Louis Michaud, 2005. "Gestion d'actifs et dérivés de crédit : opportunités et incertitudes," Revue d'Économie Financière, Programme National Persée, vol. 79(2), pages 79-93.
- Roberto Violi, 2010. "Credit ratings in structured finance and the role of systemic risk," Temi di discussione (Economic working papers) 774, Bank of Italy, Economic Research and International Relations Area.
- Morkötter, Stefan & Westerfeld, Simone, 2009. "Rating model arbitrage in CDO markets: An empirical analysis," International Review of Financial Analysis, Elsevier, vol. 18(1-2), pages 21-33, March.
- Rosenthal, Dale W.R., 2008. "Approximating correlated defaults," MPRA Paper 36788, University Library of Munich, Germany, revised 15 Feb 2012.
- Scholz, Julia, 2009. "Collateralized Debt Obligations: Anreizprobleme im Rahmen des Managements von CDOs," Discussion Papers in Business Administration 10999, University of Munich, Munich School of Management.
- Günter Franke & Markus Herrmann & Thomas Weber, 2007. "Information asymmetries and securitization design," CoFE Discussion Paper 07-10, Center of Finance and Econometrics, University of Konstanz.
- Rym Ayadi & Beat Bernet & Simona Bovha-Padilla & Tom Franck & Nancy Huyghebaert & Vitor Gaspar & Reinhilde Veugelers, 2009. "Financing SMEs in Europe," SUERF Studies, SUERF - The European Money and Finance Forum, number 2009/3 edited by Morten Balling & Beat Bernet & Ernest Gnan.
- International Monetary Fund, 2012. "Are Rating Agencies Powerful? An Investigation into the Impact and Accuracy of Sovereign Ratings," IMF Working Papers 12/23, International Monetary Fund.
- Rym Ayadi & Beat Bernet & Simone Westerfeld & Tom Franck & Nancy Huyghebaert & Vítor Gaspar & Simona Bovha-Padilla & Reinhilde Veugelers, 2009. "Financing of SMEs in Europe," Chapters in SUERF Studies, SUERF - The European Money and Finance Forum.
- Scholz, Julia, 2009. "Collateralized Debt Obligations: Anreizprobleme im Rahmen des Managements von CDOs," Discussion Papers in Business Administration 11002, University of Munich, Munich School of Management.
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