ANOVA with Three Between-Groups Factors vs. Novometric Analysis

Paul R. Yarnold

Optimal Data Analysis, LLC

ANOVA with three between-groups factors is used to compare an ordered attribute (score) between four independent categories of class variable “A”, three independent categories of class variable “B”, and two independent categories of class variable “C”. The novometric multiple regression analogue is demonstrated.

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The Australian Gun Buyback Program and Rate of Suicide by Firearm

Ariel Linden & Paul R. Yarnold

Linden Consulting Group, LLC & Optimal Data Analysis, LLC

In 1997, Australia implemented a gun buyback program that reduced the stock of firearms by around one-fifth, and nearly halved the number of gun-owning households. Leigh and Neill evaluated if the reduction in firearms availability affected homicide and suicide rates, and reported that the buyback led to a drop in the firearm suicide rates of almost 80%, with no significant effect on non-firearm death rates. In this paper we re-evaluate the suicide rate data to assess whether any directionally-correct structural breaks in the time series could be identified prior to the buy-back program. Such a change in the time series prior to the intervention may confuse causal interpretation of the actual intervention.

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