Does Health Vulnerability Predict Voting for Right-Wing Populist Parties in Europe? Yes and No, Depending on the Covariates

Introduction: A recent article by Kavanagh et al. (2021) in American Political Science Review suggested that health vulnerability predicts voting patterns for the populist far-right. Aim: We sought to distinguish socioculturally conservative from antielite voting, expecting health vulnerability to predict only the former. Methods: We combined data from the European Social Survey (round 7) with the Chapel Hill Expert Survey (2014). We preregistered several other hypotheses regarding associations between health and voting and predetermined the smallest effect size of interest (SESOI: r = .05). Results: Health vulnerability did not predict socioculturally conservative voting, and the results for antielite voting were mixed. To investigate why our result differed from Kavanagh et al.'s, we reran their analysis employing covariate specification curve analyses. The statistical significance and the direction of the association between health vulnerability and voting depended on which covariates were included. Across 1,000 models with randomly drawn covariate specifications, 59.6% showed a positive, 29.8% a zero, and 10.6% a negative association between health vulnerability and voting for far-right populist parties. However, all effect sizes were more consistently smaller than our predetermined SESOI. Conclusions: Our study illustrates the necessity of causally justifying and preregistering all covariates and predetermining an SESOI.