We introduce an adaptive importance sampling method for the loss distribution of credit portfolios based on the Robbins-Monro stochastic approximation procedure. After presenting the subtle construction of the algorithm, we apply our adaptive scheme for calculating the risk figures of a typical...

We propose a new multivariate GARCH model with Dynamic Conditional Correlations that extends previous models by admitting multivariate thresholds in conditional volatilitiesand correlations. The model estimation is feasible in large dimensions and the positive definiteness of the conditional...

We propose a simple class of semiparametric multivariate GARCH models, allowing for asymmetric volatilities and time-varying conditional correlations. Estimates for time-varying conditional correlations are constructed by means of a convex combination of estimates for averaged correlations...

We examine the quantification of operational risk for banks. We adopt a financial-economics approach and interpret operational risk management as a means of optimizing the profitability of an institution along its value chain. We start by defining operational risk and then propose a...

We propose a simple and implementable model of credit contagion where we in-clude macro- and microstructural dependencies among the debtors within a creditportfolio. We show that, even for diversified portfolios, moderate microstructuraldependencies have already a significant impact on the tails...

We present a multi-period mean-variance optimization program which allows for a joint optimization of the balance and off-balance sheet. Our first finding is the proof of a conjecture of Li and Ng (cf. [LN00]), Leippold, Trojani and Vanini (cf. [LTV04], [LTV03]) about the equivalence of the...

In this paper operational risk are considered from a purely business or profitability point of view. We show for quantifiable operational risk that the three basic figures for profitability management - value, costs and risks - can be modelled such that an integrative point of view on...

The Basel Committee on Banking Supervision ("the Committee") released a consultative document that included a regulatory capital charge for operational risk. Since the release of the document, the complexity of the concept of "operational risk" has led to vigorous and recurring discussions. We...

We revisit the apparent historical success of technical trading rules on daily prices of the Dow Jones index. First, we use the False Discovery Rate as a new approach to data snooping. The advantage of the FDR over existing methods is that it is more powerful and not restricted only to the best...

This paper examines latent risk factors in models for migration risk. We employ thestandard statistical framework for ordered categorical variables and induce dependencebetween migrations by means of latent risk factors. By assuming a Markov process forthe dynamics of the latent factors, the...