Estimation of Tails and Related Quantities Using the Number of Near-Extremes

Abstract
In an insurance context, consider {Xn, n¡Ý1} random claim sizes with common distribution function F and {N(t), t ¡Ý0} an integer valued stochastic process that counts the number of claims occurring during the time interval [0, t). Based on the number of near-extremes which are the observations Xi near the largest or the m-th largest observation we derive in this paper a strongly consistent estimator of upper tails of X1-. Further, estimators for both the tail index and the upper endpoint are introduced when F is a generalised Pareto distribution. Asymptotic normal law for the proposed estimators is additionally presented.

Keywords: Number of near-extremes, Generalised Pareto Distribution, estimation of tail index, estimation of the upper endpoint, asymptotic normality.

Volume
Berlin
Year
2003
Categories
Financial and Statistical Methods
Loss Distributions
Extreme Values
Publications
ASTIN Colloquium
Authors
Enkelejd Hashorva
Jürg Hüsler