The Markowitz (1959) mean-variance efficient frontier is the standard theoretical model for normative investment behaviour. It is still in practice the method of choice for optimal portfolio construction although among practitioners it has nearly lost its character of 'optimal' tool. Indeed it...

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...

This paper proposes a robust estimator for a general class of linear latent variable models (GLLVM) (Moustaki and Knott 2000, Bartholomew and Knott 1999). It is based on a weighted score function that is simple to implement numerically and is made consistent using the basic idea of indirect...

Robust statistics, as a concept, probably dates back to the prehistory of statistics. It has, however, been formalized in the sixties by the pioneering work of Huber and Hampel. Robust statistics is an extension of classical statistics, which takes into account the fact that models assumed to...

In this paper robustness properties of the maximum likelihood estimator (MLE) and several robust estimators for the logistic regression model when the responses are binary are analysed. It is found that the MLE and the classical Rao's score test can be misleading in the presence of model...

Estimation of the Pareto tail index from extreme order statistics is an important problem in many settings. The upper tail of the distribution, where data are sparse, is typically fitted with a model, such as the Pareto model, from which quantities such as probabilities associated with extreme...

To assess the quality of the fit in a multiple linear regression, the coefficient of determination or R2 is a very simple tool, yet the most used by practitioners. Indeed, it is reported in most statistical analyzes, and although it is not recommended as a final model selection tool, it provides...

Are academic insights effective for the real-life construction of a fund of funds, in hedge and mutual fund industries? It is typical for an academic approach to be based on ranking funds by a single quantitative measure. In practice, multiple quantitative metrics and due diligence factors are...