IDEAS home Printed from https://ideas.repec.org/p/zbw/bonedp/192009.html
   My bibliography  Save this paper

Failure of saddle-point method in the presence of double defaults

Author

Listed:
  • Lütkebohmert, Eva

Abstract

We show that the saddle-point approximation method to quantify the impact of undiversi?ed idiosyncratic risk in a credit portfolio is inappropriate in the presence of double default effects. Speci?cally, we prove that there does not exist an equivalent formula to the granularity adjustment, that accounts for guarantees, in case of the extended single-factor CreditRisk+ model. Moreover, in case of the model underlying the double default treatment within the internal ratings based (IRB) approach of Basel II, the saddle-point equivalent to the GA is too complex and involved to be competitive to a standard Monte Carlo approach.

Suggested Citation

  • Lütkebohmert, Eva, 2009. "Failure of saddle-point method in the presence of double defaults," Bonn Econ Discussion Papers 19/2009, University of Bonn, Bonn Graduate School of Economics (BGSE).
    • Handle: RePEc:zbw:bonedp:192009
    as

    Download full text from publisher

    File URL: https://www.econstor.eu/bitstream/10419/37029/1/607072318.pdf
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Peter Grundke, 2008. "Regulatory treatment of the double default effect under the New Basel Accord: how conservative is it?," Review of Managerial Science, Springer, vol. 2(1), pages 37-59, March.
    2. Lütkebohmert, Eva & Gordy, Michael B., 2007. "Granularity adjustment for Basel II," Discussion Paper Series 2: Banking and Financial Studies 2007,01, Deutsche Bundesbank.
    3. 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.
    4. Ebert, Sebastian & Lütkebohmert, Eva, 2009. "Treatment of Double Default Effects within the Granularity Adjustment for Basel II," Bonn Econ Discussion Papers 10/2009, University of Bonn, Bonn Graduate School of Economics (BGSE).
    5. Norah Barger & Erik Heitfield, 2003. "Treatment of double-default and double-recovery effects for hedged exposures under pillar I of the proposed New Basel Capital Accord," Basel II White Paper 2, Board of Governors of the Federal Reserve System (U.S.).
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Ebert, Sebastian & Lütkebohmert, Eva, 2009. "Improved Modeling of Double Default Effects in Basel II - An Endogenous Asset Drop Model without Additional Correlation," Bonn Econ Discussion Papers 24/2009, University of Bonn, Bonn Graduate School of Economics (BGSE).
    2. Gürtler, Marc & Hibbeln, Martin & Vöhringer, Clemens, 2007. "Measuring concentration risk for regulatory purposes," Working Papers IF26V4, Technische Universität Braunschweig, Institute of Finance.
    3. Ebert, Sebastian & Lütkebohmert, Eva, 2009. "Treatment of Double Default Effects within the Granularity Adjustment for Basel II," Bonn Econ Discussion Papers 10/2009, University of Bonn, Bonn Graduate School of Economics (BGSE).
    4. Klaus Duellmann & Martin Erdelmeier, 2009. "Crash Testing German Banks," International Journal of Central Banking, International Journal of Central Banking, vol. 5(3), pages 139-175, September.
    5. Tarashev, Nikola, 2010. "Measuring portfolio credit risk correctly: Why parameter uncertainty matters," Journal of Banking & Finance, Elsevier, vol. 34(9), pages 2065-2076, September.
    6. Mager, Ferdinand & Schmieder, Christian, 2008. "Stress testing of real credit portfolios," Discussion Paper Series 2: Banking and Financial Studies 2008,17, Deutsche Bundesbank.
    7. Baviera, Roberto, 2022. "The measure of model risk in credit capital requirements," Finance Research Letters, Elsevier, vol. 44(C).
    8. Roberto Baviera, 2020. "The measure of model risk in credit capital requirements," Papers 2010.08028, arXiv.org.
    9. Silvio Tarca & Marek Rutkowski, 2014. "Assessing the Basel II Internal Ratings-Based Approach: Empirical Evidence from Australia," Papers 1412.0064, arXiv.org, revised Jul 2016.
    10. Petr Jakubik & Christian Schmieder, 2008. "Stress Testing Credit Risk: Is the Czech Republic Different from Germany?," Working Papers 2008/9, Czech National Bank.
    11. Nikola A. Tarashev & Haibin Zhu, 2007. "Modelling and calibration errors in measures of portfolio credit risk," BIS Working Papers 230, Bank for International Settlements.
    12. Lee, Yongwoong & Rösch, Daniel & Scheule, Harald, 2021. "Systematic credit risk in securitised mortgage portfolios," Journal of Banking & Finance, Elsevier, vol. 122(C).
    13. Matteo Bissiri & Riccardo Cogo, 2017. "Behavioral Value Adjustments," International Journal of Theoretical and Applied Finance (IJTAF), World Scientific Publishing Co. Pte. Ltd., vol. 20(08), pages 1-37, December.
    14. Xin Huang & Hao Zhou & Haibin Zhu, 2012. "Systemic Risk Contributions," Journal of Financial Services Research, Springer;Western Finance Association, vol. 42(1), pages 55-83, October.
    15. Patrick Gagliardini & Christian Gouriéroux, 2011. "Approximate Derivative Pricing for Large Classes of Homogeneous Assets with Systematic Risk," Journal of Financial Econometrics, Oxford University Press, vol. 9(2), pages 237-280, Spring.
    16. Metzler A., 2020. "State dependent correlations in the Vasicek default model," Dependence Modeling, De Gruyter, vol. 8(1), pages 298-329, January.
    17. Arturo Cortés Aguilar, 2011. "Estimación del residual de un bono respaldado por hipotecas mediante un modelo de riesgo crédito: una comparación de resultados de la teoría de cópulas y el modelo IRB de Basilea II en datos del merca," Revista de Administración, Finanzas y Economía (Journal of Management, Finance and Economics), Tecnológico de Monterrey, Campus Ciudad de México, vol. 5(1), pages 50-64.
    18. Mendicino, Caterina & Nikolov, Kalin & Ramirez, Juan-Rubio & Suarez, Javier & Supera, Dominik, 2020. "Twin defaults and bank capital requirements," Working Paper Series 2414, European Central Bank.
    19. Rainer Masera, 2014. "CRR/CRD IV: the trees and the forest," PSL Quarterly Review, Economia civile, vol. 67(271), pages 381-422.
    20. Trueck, Stefan & Rachev, Svetlozar T., 2008. "Rating Based Modeling of Credit Risk," Elsevier Monographs, Elsevier, edition 1, number 9780123736833.

    More about this item

    Keywords

    analytical approximation; Basel II; double default; granularity adjustment; IRB approach; saddle-point approximation;
    All these keywords.

    JEL classification:

    • G31 - Financial Economics - - Corporate Finance and Governance - - - Capital Budgeting; Fixed Investment and Inventory Studies
    • G28 - Financial Economics - - Financial Institutions and Services - - - Government Policy and Regulation

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:zbw:bonedp:192009. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: ZBW - Leibniz Information Centre for Economics (email available below). General contact details of provider: https://edirc.repec.org/data/gsbonde.html .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.