Die präsentierte Studie untersuchte Bestimmungsgründe der F&E-Tätigkeit von deutschen Industrieunternehmen im Zeitraum von 1992 bis 2000. Die modelltheoretischen Analysen dienten dazu, testbare Hypothesen über wesentliche Einflussfaktoren und deren Wirkungsrichtungen auf die F&E-Aktivitäten...

In nonparametric curve estimation the decision about the type of smoothing parameter is critical for the practical performance. The nearest neighbor bandwidth as introduced by Gefeller and Dette 1992 for censored data in survival analysis is specified by one parameter, namely the number of...

Die Arbeit umfaßt die Darstellung und Anwendung von Regressionsmodellen für Zähldaten, deren abhängige Variable nur nichtnegative ganzzahlige Werte annehmen kann. Die Spezifikationen des Poisson- und des NegBin 2-Modells mit den zugehörigen Schätzverfahren und Beurteilungskriterien werden...

Probit models are employed to evaluate leading indicators for Germany's recessions. The predictive power of leading indicators is found to be lower than assumed in previous studies. Although, monetary variables provide the best predictive power for recessions, survey data and order inflows show...

Mixed proportional hazard models are commonly used to estimate duration dependence and unobserved heterogeneity in unemployment exit rates. Some strong assumptions are made in this framework, i.e. that the various influences on the individual unemployment exit rate are separable. The model we...

This paper develops the method of local instrumental variables for models with multiple, unordered treatments when treatment choice is determined by a nonparametric version of the multinomial choice model. Responses to interventions are permitted to be heterogeneous in a general way and agents...

This paper proposes a dichotomous choice model that is based on a transformed beta (or "z") distribution. This model, called betit, nests both logit and probit and allows for various skewed and peaked disturbance densities. Because the shape of this density affects the estimated relation between...

We develop a regression decomposition technique for hazard rate models, where the difference in observed rates is decomposed into components attributable to group differences in characteristics and group differences in effects. The baseline hazard is specified using a piecewise constant...

In empirical studies it often happens that some variables for some units are far away from the other observations in the sample. These extreme observations, or outliers, often have a large impact on the results of statistical analyses - conclusions based on a sample with and without these units...

We propose a novel selectivity correction procedure to deal with survey attrition, at the crossroads of the Heckit and of the bounding approach of Lee (2009). As a substitute for the instrument needed in sample selectivity correction models, we use information on the number of attempts that were...