Outlier detection in regression using an iterated one-step approximation to the Huber-skip estimator

Søren Johansen, Bent Nielsen

12 Citations (Scopus)
1966 Downloads (Pure)

Abstract

In regression we can delete outliers based upon a preliminary estimator and reestimate the parameters by least squares based upon the retained observations. We study the properties of an iteratively defined sequence of estimators based on this idea. We relate the sequence to the Huber-skip estimator.
We provide a stochastic recursion equation for the estimation error in terms of a kernel, the previous estimation error and a uniformly small error term.
The main contribution is the analysis of the solution of the stochastic recursion equation as a fixed point, and the results that the normalized estimation errors are tight and are close to a linear function of the kernel, thus providing a stochastic expansion of the estimators, which is the same as for the Huber-skip. This implies that the iterated estimator is a close approximation of the Huber-skip
Original languageEnglish
JournalEconometrics
Volume1
Issue number1
Pages (from-to)53-70
Number of pages18
DOIs
Publication statusPublished - Jun 2013

Keywords

  • Faculty of Social Sciences
  • Huber-skip
  • iteration
  • one-step M-estimators
  • unit roots

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