Während die Markpreisrisiken (Zinsen, Aktien und Währungen) mit Hilfe des RiskMetrics-Ansatzes gut beschrieben werden können und dafür relativ überzeugende Derivate zur Absicherung unerwünschter Risiken zur Verfügung stehen, hat diese Entwicklung im Kreditbereich erst begonnen. Bei der...

In den letzten Jahren hat eine intensive Entwicklung von Kreditderivaten begonnen.Im Kern soll hiermit die Möglichkeit geschaffen werden, das Adressenrisiko einer Transaktion von ihrem Marktrisiko zu separieren und es damit einzeln handelbar, aber insbesondere auch hedgebar zu machen. Die...

In this paper we focus on the analysis of the effect of prediction and estimation risk on the loss distribution, risk measures and economic capital. When variables for the determination of probability of default and loss distribution have to be predicted because they are not available at the...

Bei der Kreditrisikobewertung müssen die Parameter Ausfallwahrscheinlichkeit und korrelation geschätzt werden. Diese Schätzung erfolgt unter Unsicherheit. In der Literatur werden asymptotische Konfidenzregionen diskutiert, um diese Unsicherheit bei der simultanen Schätzung beider Parameter...

This paper provides an overview on classical and new methods for testing time series properties of migration matrices. It is well known that due to cyclical behaviour of the economy transition matrices for many credit portfolios cannot be considered to be constant through time. Further,...

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...

Rating downgrades are known to make subsequent downgrades more likely. We analyze the impact of this ?downward momentum? on credit portfolio risk. Using S&P ratings from 1996 to 2005, we estimate a transition matrix that is insensitive to and a second matrix that is sensitive to previous...

We derive approximate formulae for the credit value-at-risk and the economic capital of a large credit portfolio. The representation allows to change the risk horizon quickly and avoids simulation or numerical procedures. The Poisson mixture model is equivalent to CreditRisk and uses the same...