A primary goal in modelling the dynamics of implied volatility surfaces (IVS) aims at reducing complexity. For this purpose one fits the IVS each day and applies a principal component analysis using a functional norm. This approach, however, neglects the degenerated string structure of the...

Most dimension reduction methods based on nonparametric smoothing are highly sensitive to outliers and to data coming from heavy tailed distributions. We show that the recently proposed MAVE and OPG methods by Xia et al. (2002) allow us to make them robust in a relatively straightforward way...

This paper analyzes deviations from uncovered interest rate parity which are interpreted as indicator of the substitutability of currencies. Backward recursive statistical tests and error correction models are applied to study the co-movement of interest rates, and rolling regressions are used...

Stochastic Delay Differential Equations (SDDE) are Stochastic Functional Differential Equations with important applications. It is of interest to characterize the L2-stability (stability of second moments) of solutions of SDDE. For the class of linear, scalar SDDE we can show that second...

We model aggregate credit losses on large portfolios of financial positions contracted with firms subject to both cyclical default correlation and direct default contagion processes. Cyclical correlation is due to the dependence of firms on common (macro-) economic factors; credit contagion...

Inflation expectations are extracted from the Consumer Survey, which is conducted by the European Commission for the European Union. Using the probability method to quantify the qualitative answers different distribution functions and scaling parameters are assumed to cope with the properties of...

In this paper bilateral models formalizing monthly growth of US imports and exports are employed to investigate the potential of nonlinear relationships linking exchange rate uncertainty and trade growth. Parametric linear and nonlinear as well as semiparametric time series models are evaluated...

In frontier analysis, most of the nonparametric approaches (DEA, FDH) are based on envelopment ideas which suppose that with probability one, all the observed units belong to the attainable set. In these "deterministic" frontier models, statistical theory is now mostly available. In the presence...

Empirical studies of open-market share repurchases in the U.S. typically find a mean abnormal return around the announcement day of about 3%. In Germany share repurchases were highly restricted before May 1998. Since then firms have repurchased shares in the open market more than 250 times....

Based on a new panel dataset created in close cooperation with one of the largest temporary help agencies (THAs) in Germany, this paper presents novel evidence on key aspects of temporary agency work, a segment of the labor market that despite its growing importance remains underresearched. In...