The estimation of multivariate GARCH models remains a challenging task, even in modern computer environments. This manuscript shows how Independent Component Analysiscan be used to estimate the Generalized Orthogonal GARCH model in a fraction of the time otherwise required. The proposed method...

New Keynesian models of monetary policy predict no role for monetary aggregates, in the sense that the level of output, prices, and interest rates can be determined without knowledge of the quantity of money. This paper evaluates the empirical validity of this prediction by studying the effects...

We investigate the consequences for value-at-risk and expected shortfall purposes of using a GARCH filter on various mis-specified processes. In general, we find that the McNeil and Frey (2000) two step procedure has very good forecasting properties. Using an unconditional non filtered tail...

A resampling method based on the bootstrap and a bias-correction step is developed for improving the Value-at-Risk (VaR) forecasting ability of the normal GARCH model. Compared to the use of more sophisticated GARCH models, the new method is fast, easy to implement, numerically reliable, and,...

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...

Extreme Value Theory (EVT) has develop ed very rapidly over the past two decades both methodologically and with respect to applications. Whereas (non–life) actuaries have, at least implicitly, used EVT techniques for a long time, mainly through the emergence of quantitative Risk Management, EVT...

In this paper, we characterize explicitly the first derivative of the Value at Risk and the Expected Shortfall with respect to portfolio allocation when netting between positions exists. As a particular case, we examine a simple Gaussian example in order to illustrate the impact of netting...

We propose a general robust semiparametric bootstrap method to estimate conditional predictive distributions of GARCH-type models. Our approach is based on a robust estimator for the parameters in GARCH-type models and a robustified resampling method for standardized GARCH residuals, which...

Economic cycles are the key credit portfolio risk driver and they are autocorrelated over time. We then show that it is economically meaningful to define risk for credit portfolios in a multi period setup. Since one period expected shortfall fails to measure risk adequately in a multi period...

We consider optimization problems for minimizing conditional value atrisk (CVaR) from a computational point of view, with an emphasis on financial applications. As a general solution approach, we suggest to reformulate these CVaR optimization problems as twostage recourse problems of stochastic...