Default probabilities (PDs) and correlations play a crucial role in the New Basel Capital Accord. In commercial credit risk models they are an important constituent. Yet, modeling and estimation of PDs and correlations is still under active discussion. We show how the Basel II one factor model...

This article deals with some problems of event history analysis that arise in special types of sampling plans where spells in progress at time t0, the start date of the observation period, are sampled. Then, the available data are random samples of interrupted spells, or else may be spells that...

This article shows how Cox models can be used to study multiepisode-multistate processes as well as which computer programs can be used to estimate semiparametric models with multispell data. The application of a multiepisode Cox model is demonstrated using data on career trajectories of German...

“Arbitrage CDOs” have recorded an explosive growth during the years before the outbreak of the financial crisis. In the present paper we discuss potential sources of such arbitrage opportunities, in particular arbitrage gains due to mispricing. For this purpose we examine the risk profiles...

Im vorliegenden Beitrag wird untersucht, wie die Assetkorrelation zwischen zwei Sektoren auf einfache Weise berechnet werden kann und wie sich unterschiedliche Korrelationsannahmen auf die Form und Risikomaße von Verlustverteilungen auswirken. Dazu werden Ausfallzeitreihen von zwei...

This paper deals with the identification and maximum likelihood estimation of the parameters of a stochastic differential equation from discrete time sampling. Score function and maximum likelihood equations are derived explicitly. The stochastic differential equation system is extended to allow...

The main challenge of forecasting credit default risk in loan portfolios is forecasting the default probabilities and the default correlations. We derive a Merton-style threshold-value model for the default probability which treats the asset value of a firm as unknown and uses a factor model...