Technical paper/Default risk
Variance-covariance-based risk allocation in credit portfolios
Mikhail Voropaev proposes high-precision analytical approximation for variance-covariance-based risk allocation in a portfolio of risky assets. A general case of a single-period multi-factor Merton-type model with stochastic recovery is considered. The…
The hybrid saddlepoint method for credit portfolios
Anthony Owen, Alistair McLeod and Kevin Thompson derive a practical analytic approach, which they call the hybrid saddlepoint method, to calculate the credit loss distribution for a heterogeneous portfolio of correlated obligors
Confidence intervals for corporate default rates
Rating agency default studies provide estimates of mean default rates over multiple time horizons but have never included estimates of the standard errors of the estimates. This is due, at least in part, to the challenge of accounting for the high degree…
Confidence intervals for corporate default rates
Rating agency default studies provide estimates of mean default rates over multiple time horizons but have never included estimates of the standard errors of the estimates. This is due at least in part to the challenge of accounting for the high degree…
The probability approach to default probabilities
Default estimation for low-default portfolios has attracted attention as banks contemplate the requirements of Basel II's internal ratings-based rules. Here, Nicholas Kiefer applies the probability approach to uncertainty and modelling to default…
Calibration of PD term structures: to be Markov or not to be
A common discussion in credit risk modelling is the question of whether term structures of default probabilities can be satisfactorily modelled by Markov chain techniques. Christian Bluhm and Ludger Overbeck show that empirical multi-year default…
Going downturn
There is much debate regarding the definition of 'downturn' loss given default (LGD). In this article, Michael Barco offers an analytic approach for calculating downturn LGD so that credit risk capital is not underestimated or overestimated
Going downturn
There is much debate regarding the definition of 'downturn' loss given default (LGD). In this article, Michael Barco offers an analytic approach for calculating downturn LGD so that credit risk capital is not underestimated or overestimated
Loan portfolio value
Using a conditional independence framework, Oldrich Vasicek derives a useful limiting form for the portfolio loss distribution with a single systematic factor. He then derives a risk-neutral distribution suitable for traded portfolios, and shows how…
The probability approach to default probabilities
Default estimation for low-default portfolios has attracted attention as banks contemplate the requirements of Basel II's internal ratings-based rules. Here, Nicholas Kiefer applies the probability approach to uncertainty and modelling to default…
Default and recovery correlations - a dynamic econometric approach
Integrating coherences between defaults and loss given default (LGD) is postulated by Basel II. If there is a positive correlation between the two, separate models for each lead to biased estimates for the LGD parameters, and the economic loss is…
Default and recovery correlations - a dynamic econometric approach
Integrating coherences between defaults and loss given default (LGD) is postulated by Basel II. If there is a positive correlation between the two, separate models for each lead to biased estimates for the LGD parameters, and the economic loss is…
Intensity gamma
Mark Joshi and Alan Stacey develop a new model for correlation of credit defaults based on a financially intuitive concept of business time similar to that in the variance gamma model for stock price evolution
An empirical analysis of equity default swaps (II): multivariate insights
Equity default swaps (EDSs) have attracted much attention recently because of their similarities to credit default swaps on the one hand and American-style digital puts on the other. Particular interest has focused on collateralised debt obligations…
Estimating default correlations using a reduced-form model
Credit risk : Cuttingedge
Maximum likelihood estimate of default correlations
Estimating asset correlations is difficult in practice since there is little available data andmany parameters have to be found. Paul Demey, Jean-Frédéric Jouanin, Céline Roget andThierry Roncalli present a tractable version of the multi-factor Merton…
Mixed default modelling
Structural and reduced-form models are two well-established approaches to modelling afirm’s default risk. Here, Li Chen, Damir Filipovic/ and Vincent Poor develop a new default riskmodelling strategy based on combining these two frameworks in order to…
The score for credit
Jorge Sobehart and Sean Keenan discuss the benefits and limitations of model performance measures for default and credit spread prediction, and highlight several common pitfalls in the model comparison found in the literature and vendor documentation. To…
Collateral damage
Credit risk
Correlation evidence
Like ratings, default correlation is an area of fierce industry debate. But any fundamental, long-terminvestor searching for fair value in credit correlation will want to understand what the historical dataactually says.
Correlation evidence
Like ratings, default correlation is an area of fierce industry debate. But any fundamental, long-term investor searching for fair value in credit correlation will want to understand what the historical data actually says. Here, Arnaud de Servigny and…
The road to partition
Applying the ensemble approach developed in these pages last month, Kevin Thompson and Roland Ordovas calculate risk contributions and show how to measure higher-order default dependence using the method of partitions. The results provide tools allowing…
Credit ensemble
Kevin Thompson and Roland Ordovas address the question of how individual counterparties contribute to the total credit risk of a portfolio. They provide an analytic method, new to credit modelling, to estimate all joint default statistics conditional…