Technical paper/Credit risk
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…
Expected shortfall - una coda in due parti
APPROFONDIMENTI. RISCHIO DEL PORTAFOGLIO CREDITI
Credit risk contagion
In a recession, company defaults increase due to both the worsening economic environment and the specific links between customers and suppliers. Banks intuitively know that customer default can cause supplier default. Duncan Martin and Chris Marrison…
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…
Shortfall: a tail of two parts
Richard Martin and Dirk Tasche show that the expected shortfall, when used in the conditional independence framework, has an elegant decomposition into systematic (risk-factor-driven) and unsystematic parts. The theory is compared and contrasted with the…
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…
An indirect view from the saddle
The saddlepoint method has become established as a tool for portfolio analysis. In this article, Richard Martin and Roland Ordovas review the main concepts and show that there are two essentially distinct ways of applying it to conditional independence…
Dynamic frailties and credit portfolio modelling
Martin Delloye, Jean-David Fermanian and Mohammed Sbai estimate and discuss a reduced-form credit portfolio model in a proportional hazard framework. They propose an innovative method of generating flexible amounts of dependence between underlying…
Dealing with seller's risk
The risk of trade receivables securitisations comes from both the pool of assets and the seller of the assets. Vivien Brunel develops a model for securitisation exposures that deals with both risks, and analyses in detail the interplay between debtors'…
Modelling and estimating dependent loss given default
Martin Hillebrand proposes a portfolio credit risk model with dependent loss given default (LGD), offering a reasonable economic interpretation that is easily applicable to real data. He builds a precise mathematical framework, and stresses some…
Strategie di trading sulla pendenza
DERIVATI CREDITIZI
Low-default portfolios without simulation
Low-default portfolios are a key Basel II implementation challenge, and various statistical techniques have been proposed for use in PD estimation for such portfolios. To produce estimates using these techniques, typically Monte Carlo simulation is…
A saddle for complex credit portfolio models
Guido Giese applies the saddle-point approximation to analyse tail losses for very general credit portfolios, including correlated defaults, stochastic recovery rates, and dependency between default probabilities and recovery rates. The numerical…
Wrong way risk modelling
Beyond its potential impact on counterparty risk exposure, the wrong way risk arising in some derivatives transactions raises important modelling challenges. Christian Redon presents two suitable models based on conditional expected exposure. Among…
Time for multi-period capital models
Several financial institutions use single-period models to determine their credit portfolio loss distribution, calculate their loss volatility and assign economic capital.
Time for multi-period capital models
Several financial institutions use single-period models to determine their credit portfolio loss distribution, calculate their loss volatility and assign economic capital. Here, Kevin Thompson, Alistair McLeod, Panayiotis Teklos and Shobhit Gupta…
Time for multi-period capital models
Several financial institutions use single-period models to determine their credit portfolio lossdistribution, calculate their loss volatility and assign economic capital. Here, Kevin Thompson,Alistair McLeod, Panayiotis Teklos and Shobhit Gupta…
Co-monotonic default quote paths for basket evaluation
Cutting edge: Credit portfolio risk