The Mechanical and Psychological Consequences of Alternative Voting Methods: Polarizing Parties and Strategic Behavior in the 2022 Italian Election

When voters provide more information about their political preferences compared to just supporting one party, some consequences are found in the literature such as disfavoring "polarizing" candidates – those strongly supported by a niche of voters and opposed by many others – and favoring "consensual" ones, those gathering moderate support by voters with different political orientations. In an online survey preceding the 2022 Italian general election with a nationally representative sample of Italian voters (N = 1,021), we tested alternative voting methods’ consequences by giving participants the possibility of approving, ranking, and evaluating as many parties as they wanted. Our findings show that alternative methods would (a) not change the election winner, (b) decrease the rankings of independent – especially transversal – compared to coalition parties, and (c) increase the vote shares of small parties. Most respondents were expressive and sincere when casting alternative votes. Polarizing and consensual parties are then defined according to voters’ sincere opinions on parties – which are independent of voting strategies unlike vote distributions – through the t-distributed stochastic neighbor embedding (t-SNE) dimension reduction algorithm. Transversal Five Star Movement and far-right Brothers of Italy parties display polarizing features such as eliciting more extreme opinions and having more exclusive supporters.