infonet-economy

When using smoothing splines to estimate a function, the user faces the problem of choosing the smoothing parameter. Several techniques are available for selecting this parameter according to certain optimality criteria. Here, we take a different point of view and we propose a technique for choosing between two alternatives, for example allowing for two different levels of degrees of...

In this paper, we consider the problem of outliers in incomplete multivariate data, when the aim is to estimate a measure of mean and covariance as it is the case for example in factor analysis. In such a situation the ER algorithm of Little and Smith (1987) which combines the EM algorithm for missing data and a robust estimation step based on an Mestimator could be used. However,...

The paper discusses the effect of model deviations such as data contamination on the maximum likelihood estimator (MLE) for a general class of latent trait models (citeNP{MoKn:00}). This is done with the use of the influence function (Hampel 1968, 1974) a mathematical tool to assess the robustness properties of any statistic, such as an estimator. Simulation studies show that the MLE...

Paneldaten gewinnen als Datenmaterial für empirische Studien im Bereich der Wirtschaftswissenschaften, sowie auch in vielen anderen empirisch ausgerichteten Forschungsfeldern, eine immer grössere Bedeutung. Das Papier gibt einen nichttechnischen Überblick über in der ökonometrischen Paneldatenanalyse populäre lineare und nichtlineare Modelle und diskutiert die Annahmen, unter denen...