Vasicek Model Extension. Premature default

Maksim Osadchiy

MPRA Paper from University Library of Munich, Germany

Abstract: The IRB approach underlies Basel II and Basel III. The approach is based on the Vasicek distribution. The main advantage of the distribution is simplicity and accounting for default correlation. But the distribution substantially underestimates probability of default due to ignoring of premature defaults. Besides, the IRB approach uses the maturity adjustment, which is a kind of a black box, since there is no clear information about the econometric model and calibration of its parameters. If maturity exceeds one year, the IRB formula leads to negativity and even discontinuity of capital in the neighborhood of zero default probability. The paper suggests the Vasicek-Black-Cox (VBC) model, which is constructed to fix drawbacks of the IRB approach. The VBC model is constructed on the base of the Vasicek model and the Black-Cox model. The Vasicek model is a special case of the VBC model, designed to evaluate the default distribution taking into account premature defaults. The VBC model was constructed using the Method of Images, since the firm in the framework of the Black-Cox model is treated as the barrier binary option.

Keywords: IRB; Vasicek; Merton; Black-Cox; barrier options; default distribution (search for similar items in EconPapers)
JEL-codes: G21 G32 G33 (search for similar items in EconPapers)
Date: 2021-07-07
New Economics Papers: this item is included in nep-acc, nep-ore and nep-rmg
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://mpra.ub.uni-muenchen.de/108687/1/MPRA_paper_108687.pdf original version (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:pra:mprapa:108687

Access Statistics for this paper

More papers in MPRA Paper from University Library of Munich, Germany Ludwigstraße 33, D-80539 Munich, Germany. Contact information at EDIRC.
Bibliographic data for series maintained by Joachim Winter ().