Who's favored by evaluative voting? An experiment conducted during the 2012 French presidential election

Abstract

Under evaluative voting, the voter freely grades each candidate on a numerical scale, with the winning candidate being determined by the sum of the grades they receive. This paper compares evaluative voting with the two-round system, reporting on an experiment which used various evaluation scales, conducted during the first round of the 2012 French presidential election. Invitations to participate in the study were extended to around 5,000 voters in three cities, and the experiment attracted 2,340 participants. Basing our argument on the * We extend grateful thanks to all the members of the Community Councils, all the participants, and all the volunteers who helped us on April 22.(See http://www.gate.cnrs.fr/spip.php?rubrique94#Merci).† GATE L-SE (UMR CNRS 5824), University Jean Monnet, 42 000 Saint-Etienne, France, antoinette.baujard@univ-st-etienne.fr ‡ CREM (UMR CNRS 6211), University of Caen Basse-Normandie, 14 000 Caen, France, frederic.gavrel@unicaen.fr § CNRS and Beta (UMR CNRS 7522), University of Strasbourg, 67 085 Strasbourg,France, igersheim@unistra.fr ¶ PREG (UMR CNRS 7176), Ecole polytechnique, 91 128 Palaiseau, France, jeanfrancois.laslier@polytechnique.edu CREM (UMR CNRS 6211), University of Caen Basse-Normandie, 14 000 Caen, France isabelle.lebon@unicaen.fr 1 ranks, relative scores, and grade profiles of candidates, we show that the two-round system favors "exclusive" candidates, that is candidates who elicit strong feelings, while evaluative rules favor "inclusive" candidates, that is candidates who attract the support of a large span of the electorate. These differences are explained by two complementary reasons: the opportunity for the voter to support several candidates under evaluative voting rules, and the specific pattern of strategic voting under the official, two-round voting rule. Classification JEL: D72, C93Keywords: Voting, In Situ Experiment, Evaluative Voting, Approval Voting, Two-round system Highlights• The two-round system favors "exclusive" candidates, that is candidates who elicit strong feelings.• Evaluative rules favor "inclusive" candidates, that is candidates who attract the support of a large span of the electorate.• One explanation of the differences between the elections wins and rankings between the two-round system and evaluative voting rules is that the opportunity for the voter to support several candidates under evaluative voting rules.• One explanation of the differences between the elections wins and rankings between the two-round system and evaluative voting rules relies in the specific pattern of strategic voting under the official, two-round voting rule. 2A voting rule is supposed to be able to determine the candidate most favored by a community of voters. However, it is a well-established conclusion of social choice theory that voting by itself is mathematically incapable of picking the single and uncontroversial winner of an election (Arrow 1957).For a given set of electoral preferences, different voting rules may elect or favor distinct candidates (F...

How Voters Use Grade Scales in Evaluative Voting

“…Each participant tested two alternative rules for deciding on the ten candidates in this election: approval voting and a variant of evaluative voting. We refer the reader to Baujard et al (2013) for a complete presentation of the protocol, and to Grofman et al (2011) for more details of the in situ methodology. 4 The experiment was performed in five polling stations.…”

“…Baujard et al (2014) showed that candidates fall into three categories according to how they are perceived by the electorate.…”

“…In our case, we do not have such variables but we directly have access to the individual political standing through the official vote, at least for those participants who effectively stated it. We take as the reference distribution the actual distribution of the votes in the 2012 first round of the official election so that both the site representation bias and the voter participation bias should be offset (see Baujard et al 2013 for more details). The rankings of the candidates from the different grade scales are thus comparable both to each other and to the official national results.…”

“…But we do not know very much about this. There are very few references in the academic literature comparing different forms of grade voting in practice (Baujard et al 2014, Igersheim et al 2016). This paper is not an activist stance to defend evaluative voting, it is a contribution to the scientific debate on the relative qualities and shortcomings of grade voting systems.…”

Mean-median compromise method as an innovating voting rule in social choice theory

“…For example, it is more likely strategyproof than BMC or any other form of voting based on the summation or the average of grades. Indeed, it generalizes the approval voting, one of the most valued functions according to many specialists in Social Choice Theory (see [19,20,21]). …”