Für die Käufer von Sammelbildern stellt sich häufig die Frage, wie viele Käufe sie tätigen müssen, um eine bestimmte Anzahl von Bildern, die zu Gruppen in Tüten verpackt sind, zu erhalten. Zur Lösung dieser und ähnlicher Fragen untersuchen wir Verallgemeinerungen des Belegungsproblems...

Keynes (1911) derived general forms of probability density functions for which the "most probable value" is given by the arithmetic mean, the geometric mean, the harmonic mean, or the median. His approach was based on indirect (i.e., posterior) distributions and used a constant prior...

Most software reliability growth models specify the expected number of failures experienced as a function of testing effort or calendar time. However, there are approaches to model the development of intermediate factors driving failure occurrences. This paper starts out with presenting a model...

A number of recent studies have reported the phenomenon of “software aging”, characterized by progressive performance degradation and/or an increased occurrence rate of hang/crash failures of a software system due to the exhaustion of operating system resources or the accumulation of errors....

Many software reliability growth models assume that the time to next failure may be infinite; i.e., there is a chance that no failure will occur at all. For most software products this is too good to be true even after the testing phase. Moreover, if a non-zero probability is assigned to an...

Over the past 15 years,there have been a number of studies using text mining for predicting stock market data. Two recent publications employed support vector machines and second-order Factorization Machines, respectively, to this end. However, these approaches either completely neglect...

Dieser Beitrag gibt einen Überblick über aktuelle Forschungsprojekte des Instituts für Arbeitsmarkt- und Berufsforschung (IAB), die sich alle auf unterschiedliche Weise mit der Behebung von Problemen mit Missing Data befassen. Hierzu gehören einerseits Projekte, die Stichproben verwenden wie...

This paper makes three contributions to the literature on the effects of collective bargaining on the performance of German establishments. We include the analysis of firms' efficiency and we model productivity and efficiency simultaneously. Confronted with 25 % observations with missing values,...

This paper illustrates the effects of item-nonresponse in surveys on the results of multivariate statistical analysis when estimation of productivity is the task. To multiply impute the missing data a data augmentation algorithm based on a normal/Wishart model is applied. Data of the German IAB...

In this paper, stochastic production frontier models are estimated with IAB establishment data from waves 2002 and 2003 to find important determinants of productivity and ineffciency. The data suffer from nonresponse in the most important variables (output, capital and labor) leading to the loss...