Modelling sources of ecological fallacy within a revised Brown and Payne model of voting transitions

TL;DR

This paper introduces a refined statistical model for voting behavior that accounts for ecological fallacy, enabling detection of confounding effects from aggregate covariates, demonstrated through an application to Milan referendum data.

Contribution

It presents a more realistic and improved model for voting transitions that can test for confounding effects, addressing limitations of previous models.

Findings

Model can detect confounding effects from aggregate covariates.

Application to Milan referendum illustrates model's practical utility.

Model reduces bias in estimating voting transition relationships.

Abstract

We present a model of voting behaviour based on a version of aggregated overdispersed multinomial distributions; relative to a similar model by \citet{BP86}, our model is based on more realistic assumptions and free from certain shortcomings of the previous model. We show that, within this model, it is possible to test for certain confounding effects due to observable covariates measured at the aggregate level; such effects, if ignored, might cause substantial bias in the estimated relation between voting decisions in two close in time elections, a phenomenon known as {\em Ecological Fallacy}. An application to a referendum following an election for the major in the town of Milan, which was interpreted as a defeat for the Berlusconi gouvernment, is used as an illustration.