Comment on "Assessing CN earthquake predictions in Italy" by M. Taroni, W. Marzocchi, P. Roselli

TL;DR

This paper critiques the use of standard statistical methods and the Pari-mutuel Gambling Score in assessing earthquake predictions by the CN algorithm in Italy, highlighting their limitations with small sample sizes.

Contribution

It provides a critical analysis of the evaluation methods used for earthquake prediction performance, emphasizing the inadequacy of standard tests and PGS in small-sample scenarios.

Findings

Standard statistical methods are ineffective with limited earthquake data.

PGS method results in significant information loss about predictions.

Conclusions based on PGS are unreliable for small sample earthquake prediction assessments.

Abstract

The paper by Taroni et al. (2016) considers results of forward prediction of Italian strong earthquakes by CN algorithm with the declared intent of providing "a careful assessment of CN prediction performances... using standard testing procedures". Given the very limited number of target events within each region, however, the considered situation is non statistical, and a priori it is clear that the standard statistical methods are not effective here. The attempt to replace the standard approaches by Pari-mutuel Gambling Score (PGS) method leads to almost complete loss of information about predicted earthquakes, even for a large sample of target events. Therefore, the conclusions based on PGS, are untenable.