Several methods have been proposed for identifying clusters of extreme values leading to estimators of the extremal index; the latter represents,in the limit, the mean-size of each cluster of thresholds exceedances. The detection of clusters of extremes is relevant for the class of processes...

Purpose: The study develops a decision support system for the spatial distribution of store flyers, identifying a number of factors related to the demand and the competition influencing the complexities of their allocation to the target population. Design/methodology/approach: The model was...

Standard methods for optimal allocation of shares in a financial portfolio are determined by second-order conditions which are very sensitive to outliers. The well-known Markowitz approach, which is based on the input of a mean vector and a covariance matrix, seems to provide questionable...

The recent financial crisis has accentuated the fact that extreme outcomes have been overlookedand not dealt with adequately. While extreme value theories have existed for a long time, themultivariate variant is difficult to handle in the financial markets due to the prevalentheteroskedasticity...