Comparing voting methods: 2016 US presidential election

Herrade Igersheim,François Durand,Aaron Hamlin,Jean-François Laslier

doi:10.1016/j.ejpoleco.2021.102057

Abstract

This paper presents data from a survey leading up to the 2016 US presidential elections. Participants were asked their opinions about the candidates and were also asked to vote according to three alternative voting rules, in addition to plurality: approval voting, range voting, and instant runoff voting. The participants were split into two groups, one facing a set of four candidates (Clinton, Trump, Johnson, and Stein) and the other a set of nine candidates (the previous four plus Sanders, Cruz, McMullin, Bloomberg, and Castle). The paper studies three issues: (1) How do US voters use these alternative rules? (2) What kinds of candidates, in terms of individual preferences, are favored by which rule? (3) Which rules empirically satisfy the independence of eliminated alternatives? Our results provide evidence that, according to all standard criteria computed on individual preferences, be there utilitarian or of the Condorcet type, the same candidate (Sanders) wins. Evaluative voting rules such as approval voting and range voting might lead to this outcome, contrary to direct plurality and instant runoff voting (that elects Clinton) and to the official voting rule (that elected Trump).

Highlights

Since November 2016, both the US and worldwide media have emphasized that the sitting Republican president Donald Trump did not get the majority of the votes
We focus our analyses on the long set, in order to examine why Range voting (RV), honestly the candidates (HA), and Approval voting (AV) may produce different winners compared to plurality
Our results show that multi-nominal evaluative voting rules such as RV and, potentially, AV would have led to elect Sanders among a large set of candidates, in contrast to direct plurality and to the official voting rule

Summary

Introduction

Since November 2016, both the US and worldwide media have emphasized that the sitting Republican president Donald Trump did not get the majority of the votes. A stream of research has emerged that is testing approval voting and other multi-nominal rules alongside large-scale official elections. Such experiments have been conducted in France since 2002 in parallel to presidential elections (Baujard and Igersheim 2010, Grofman et al 2011, Baujard et al 2014), and similar protocols have been used in Germany (Alos-Ferrer and Granic 2010). To the best of our knowledge, there is no research aiming to test multi-nominal voting rules in a U.S national election context For those who are 18 years or older and those who haven’t had a felony and aren’t currently in prison (some states restrict felons). This shows that exclusion was rare, suggesting that respondents took the survey seriously

Global behavior and assessment of the tested voting rules

From the short set to the long set: the question of “irrelevant alternatives”

From plurality to multi-nominal voting rules: a modification of the winner

Findings

Concluding remarks