Research in combining of economic forecasts made by several research institutes on the same economic variable has focused on estimation, hoping that the combined forecast will be improved by taking into account the expert opinions of the institutes. We provide a confidence interval on the...

In this paper we derive asymptotic x 2 - tests for general linear hypotheses on variance components using repeated variance components models. In two examples, the two-way nested classification model and the two-way crossed classification model with interaction, we explicitly investigate the...

Different estimation methods for covariance parameters in meta-analyses can result in conflicting p-values concerning the test of treatment effect. We propose a valid method to overcome this problem at least partially by introducing a new estimator for the standard deviation of the common...

Concerning the actual significance level, we investigate the commonly used combined test procedures of meta-analysis, which contain the choice of the model, in which the analysis is carried out, and the commonly used tests for treatment effect in the fixed and random effects model, and some new...

In many meta-analysis cases the estimator of the overall effect in independent trials or experiments leads to unjustified significant results. This paper considers trials with two arms where the summary statistic of interest is either the mean difference or the risk difference. By using...

A confidence interval for the between group variance is proposed which is deduced from Wald’s exact confidence interval for the ratio of the two variance components in the one-way random effects model and the exact confidence interval for the error variance resp. an unbiased estimator of the...

In einer Re-Analyse der Blue Mountains Eye Study von Cumming, Mitchell und Leeder (1997) wird gezeigt, daß diese Studie keinen Beitrag zur Klärung des Kataraktrisikos von inhalativen Kortikoiden leistet. Akzeptiert man die Schlußweisen der Studie, so ergibt sich ein diffuses und zugleich aber...

The variance function of the optimal estimator of the overall mean in a heteroscedastic one-way ANOVA model is dominated by positive semi-definite quadratic functions. This makes it possible to develop closely related tests on the nullity of the overall mean parameter in one-way fixed and random...

Mit Hilfe einer numerischen Meta-Analyse wird gezeigt, daß in placebokontrollierten klinischen Studien mit vergleichbarem Studiendesign und vergleichbarer Zielvariable die Behandlung der funktionellen Dyspepsie mit einem Gastroprokinetikum (Cisaprid) erfolgreicher ist als mit...