Credit risk has many facets - such as spread risk, default (jump) risk, migrational risk and correlation risk - that are modeled separately under the current Basel framework. We propose a risk metric called credit Bubble VaR (Cr. buVaR) that combines these risks under a common historical...

Results from portfolio models for credit risk tell us that loan concentration in certain industry sectors can substantially increase the value-at-risk (VaR). The purpose of this paper is to analyze whether a tractable "infection model" can provide a meaningful estimate of the impact of...

In credit risk modelling, the correlation of unobservable asset returns is a crucial component for the measurement of portfolio risk. In this paper, we estimate asset correlations from monthly time series of Moody's KMV asset values for around 2,000 European firms from 1996 to 2004. We compare...

Stress testing has become a crucial point on the Basel II agenda, mainly as Pillar I estimates do not explicitly take portfolio concentration into account. We start from the credit portfolio of the German pension insurer being a cross-sectional representation of the German economy and...

We study the implications of the value at risk concept for the bank's optimum amount of equity capital under credit risk. The market value of loans is risky and lognormally distributed. We show that the required equity capital depends upon managerial and market factors. Furthermore, the bank's...

This paper uses Monte Carlo simulations to assess the impact of noisy inputparameters on the accuracy of estimated portfolio credit risk. Assumptionsabout input quality are derived from the distribution of historical samplestatistics commonly used in default risk modelling. The resulting...

Counterpart risk rating is at the heart of the banking business. In the new Basel II regulation, internal ratings have been given a central role. Although much research has been done on external ratings, much less is known about banks´ internal ratings. This paper presents new quantitative...

The Internal Ratings Based (IRB) approach for capital determination is one of the cornerstones in the proposed revision of the Basel Committee rules for bank regulation. We evaluate the IRB approach using historical business loan portfolio data from a major Swedish bank for the period 1994 to...

A drawback of available portfolio credit risk models is that they fail to allow for default risk dependency across loans other than through common risk factors. Thereby, thesemodels ignore that close ties can exist between companies due to legal, financial and business relations. In this paper,...

M-PRESS-CreditRisk is a new top-down macro stress testing framework that can help supervisors gauge banks' capital adequacy related to credit risk. For the first time, it combines calibration of microprudential capital requirements and macroprudential buffers in a unified, coherent framework....