Analysis of estimation methods for the extremal index

Many datasets present time-dependent variation and short-term clustering within extreme values. The extremal index is a primary measure to evaluate clustering of high values in a stationary sequence. Estimation procedures are based on the choice of a threshold and/or a declustering parameter or a bl...

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Bibliographic Details
Main Author: Ferreira, Marta Susana (author)
Format: article
Language:eng
Published: 2018
Subjects:
Online Access:http://hdl.handle.net/1822/55225
Country:Portugal
Oai:oai:repositorium.sdum.uminho.pt:1822/55225
Description
Summary:Many datasets present time-dependent variation and short-term clustering within extreme values. The extremal index is a primary measure to evaluate clustering of high values in a stationary sequence. Estimation procedures are based on the choice of a threshold and/or a declustering parameter or a block size. Here we revise several different methods and compare them through simulation. In particular, we will see that a recent declustering methodology may be useful for the popular runs estimator and for a new estimator that works under the validation of a local dependence condition. An application to real data is also presented.