Model risk as part of the operational risk is a serious problem for financial institutions.As the pricing of derivatives as well as the computation of the marketor credit risk of an institution depend on statistical models the application of awrong model can lead to a serious over- or...

This paper analyzes and quantifies the idea of model risk in the environment of internal modelbuilding. We define various types of model risk including estimation risk, model risk in distributionand model risk in functional form. By the quantification of these concepts we analyzethe impact of...

Als Teil des operationellen Risikos stellt das Modellrisiko eine wichtige Komponente f¨urdie Risikoermittlung bei Finanzinstitutionen dar. Da letztere z.B. bei der Tarifierung undBepreisung von Derivaten bzw. Portfolien oder bei der Markt- und Kreditrisikoberechnungauf stochastische Modelle...

Die Berechnung des VaR führt zur Reduktion der Dimension des Raumes der Risikofaktoren. Die vorzunehmenden Vereinfachungen resultieren aus unterschiedlichen Beweggründen, z.B. technische Effizienz, Sachlogik der Ergebnisse und statistische Adäquanz des Modells. Im Kapitel 2 stellen wir drei...

Within an internal model the Economic Scenario Generator (ESG) is an important component. In orderto get a regulatory approval of an internal model it is required that the implemented models (must be) passeda rigorous validation process, see Ceiops [2009].In this paper we focus on the particular...

In ESTAR models it is usually dfficult to determine parameter estimates, as it can be observedin the literature. We show that the phenomena of getting strongly biased estimators is aconsequence of the so-called identication problem, the problem of properly distinguishing thetransition function...

Determining good parameter estimates in ESTAR models is known to be difficult. We showthat the phenomena of getting strongly biased estimators is a consequence of the so-calledidentication problem, the problem of properly distinguishing the transition function in relationto extreme parameter...

While it is widely agreed that Purchasing Power Parity (PPP) holds as a long-runconcept the specific dynamic driving the process is largely build upon a priori economicbelief rather than a thorough statistical modeling procedure. The two prevailing timeseries models, i.e. the exponential smooth...

We study the empirical behaviour of semi-parametric log-periodogram estimation forlong memory models when the true process exhibits a change in persistence. Simulationresults confirm theoretical arguments which suggest that evidence for long memory islikely to be found...

We develop a Wald type test to distinguish between long memory and ESTARnonlinearity by using a directed-Wald statistic to overcome the problem of restricted parametersunder the alternative. The test is derived from two basic model specificationswhere the first is the standard model based on an...