The Relationship between Ideology and COVID-19 Deaths: What We Know and What We Still Need to Know

por Lorena Barberia, Natália de Paula Moreira, Rebeca de Jesus Carvalho, Maria Leticia Claro Oliveira, Isabel Seelaender Costa Rosa, Marcela Zamudio


Several recent studies have investigated if support for Jair Bolsonaro in the presidential election of 2018 is positively associated with COVID-19 infections and deaths in Brazil. In these studies, COVID-19 outcomes in 2020 and 2021 are the dependent variables, and votes for Jair Bolsonaro in the 2018 presidential election (as a proxy for ideology) are the key explanatory variable. This article discusses why ecological research designs are difficult to test empirically. We discuss why correlations between vote shares and COVID-19 outcomes using aggregate data can produce biased inferences, and we specifically focus on measurement error, aggregation bias, and spatial and temporal dynamics.


Ecological inference; measurement error; omitted variable bias; temporal dynamics.