A new algorithm for adjusting correlation matrices and for comparison with Finger's algorithm, which is used to compute Value-at-Risk in RiskMetrics for stress test scenarios. The solution proposed by the new methodology is always better than Finger's approach in the sense that it alters as...

Choice functions on tournaments always select the maximal element (Condorcet winner), provided they exist, but this property does not hold in the more general case of weak tournaments. In this paper we analyze the relationship between the usual choice functions and the set of maximal elements in...

A weaker than usual continuity condition for acyclic preferences is introduced. For preorders this condition turns out to be equivalent to lower continuity, but in general this is not true. By using this condition, a numerical representation which is upper semicontinuous is obtained. This fact...

Tournaments are complete and asymmetric binary relations. This type of binary relation rules out the possibility of ties or indifferences which are common in different contexts. In this work we generalize, from a normative point of view, some important tournaments solutions (top cycle, uncovered...

The existence of maximal elements for binary preference relations is analyzed without imposing transitivity or convexity conditions. From each preference relation a new acyclic relation is defined in such a way that some maximal elements of this new relation characterize maximal elements of the...

In a choice situation, it is usually assumed that the agents select the maximal elements inaccordance with their preference relation. Nevertheless, there are situations in which a selectioninside this maximal set is needed. In such a situation we can select randomly some of thesemaximal...

This paper deals with the existence and properties of the demand correspondence when agents' preferences are pseudotransitive. It is shown that a consumption plan belongs to the demand mapping if and only if it is a maximizer of a real-valued weak utility function. Further properties, as...

Following the work of Bandyopadhyay and Sengupta, we analyze the rationalization of a choice function in terms of the revealed preference but in a more general context: choice sets with a continuum of alternatives. Firstly it is proved that some results which are verified in the finite case are...

A new voting rule for electing committees is described. Specifically, we use approval balloting and propose a voting procedure guaranteeing that if a committee representing (in a determined proportion) all voters exists, then the selected committee has to represent all voters at least in the...

In this paper we consider convex combinations of matrices that arise in the study of distribution problems and analyse the properties of Perron's eigenvalue, and its associated positive eigenvector. We prove that the components in the (normalized) associated positive eigenvector have a monotone...