Subsampling techniques and the Jackknife methodology in the estimation of the extremal index

  • Authors:
  • M. Ivette Gomes;Andreia Hall;M. Cristina Miranda

  • Affiliations:
  • Universidade de Lisboa, DEIO (FCUL) and CEAUL, 1749-016 Lisboa, Portugal;CEA and DM, Universidade de Aveiro, Portugal;ISCA, Universidade de Aveiro and CEAUL, Universidade de Lisboa, Portugal

  • Venue:
  • Computational Statistics & Data Analysis
  • Year:
  • 2008

Quantified Score

Hi-index 0.03

Visualization

Abstract

For a sequence of independent, identically distributed random variables any limiting point process for the time normalized exceedances of high levels is a Poisson process. However, for stationary dependent sequences, under general local and asymptotic dependence restrictions, any limiting point process for the time normalized exceedances of high levels is a compound Poisson process, i.e., there is a clustering of high exceedances, where the underlying Poisson points represent cluster positions, and the multiplicities correspond to the cluster sizes. For such classes of stationary sequences there exists the extremal index@q, 0=0 for ''almost all'' cases of interest. The estimation of the extremal index through the use of the Generalized Jackknife methodology, possibly together with the use of subsampling techniques, is performed. Case studies in the fields of environment and finance will illustrate the performance of the new extremal index estimator comparatively to the classical one.