UNCONVENTIONAL FEATURES OF POSITIVE-BREAKDOWN ESTIMATORS

This paper reviews some aspects of positive-breakdown regression that have been discussed. Apart from efficiency, also some related topics are addressed in order to obtain a broader view. Several unusual aspects are shown to be intimately connected with the exact fit property. It is argued that the latter is not a drawback but an interesting property, which helps to explain why positive-breakdown estimators often succeed at revealing a hidden structure in the data.