On public opinion polls and voters' turnout

• Published date: 01 April 2018
• DOI: http://doi.org/10.1111/jpet.12274
• Author: Esteban F. Klor,Eyal Winter
• Date: 01 April 2018

Received: 26 July 2016 Accepted: 25 August 2017

DOI: 10.1111/jpet.12274

ARTICLE

On public opinion polls and voters'turnout

Esteban F.Klor1Eyal Winter2

1Departmentof Economics, The Hebrew

Universityof Jerusalem and CEPR

2Departmentof Economics and the Center for

theStudy of Rationality, The Hebrew University

ofJerusalem

Wethank the editor and two anonymous review-

ersfor their comments and suggestions. We are

alsograteful to Oriol Carbonell-Nicolau, Eric

Gould,Dan Levin, Rebecca Morton, Bradley Ruf-

fle,and Moses Shayo for very helpful discussions.

Wethank Hernan Meller for his valuable research

assistanceand Brad Coker from Mason-Dixon

Pollingand Research, Inc. for providing us with

thedata on gubernatorial elections. The paper

hasbenefited from the comments of audiences at

seminarsand conferences too many to mention.

Allerrors and mistakes in the paper remain our

own.

EstebanF. Klor,Department of Economics, The

HebrewUniversity of Jerusalem, Mount Scopus,

Jerusalem,91905, Israel (eklor@huji.ac.il).

EyalWinter, Department of Economics, The

HebrewUniversity of Jerusalem, Mount Scopus,

Jerusalem,91905, Israel (mseyal@mscc.huji.ac.il).

This paper studies the effects that the revelation of information on

the electorate's preferences has on voters'turnout. The experimen-

tal data show that closeness in the division of preferences induces

a significant increase in turnout. Moreover, for closely divided elec-

torates (and only for these electorates), the provision of informa-

tion significantly raises the participation of subjects supporting the

slightly larger team relative to the smaller team. We show that the

heterogeneous effect of information on the participation of subjects

in different teams is drivenby the subjects'(incorrect) beliefs of cast-

ing a pivotal vote. Simply put, subjects overestimate the probabil-

ity of casting a pivotal vote when they belong to the team with a

slight majority, and choose the strategy that maximizes their utility

based on their inflated probability assessment. Empirical evidence

on gubernatorial elections in the United States between 1990 and

2005 is consistent with our main experimental result. Namely, we

observethat the difference in the actual vote tally between the party

leading according to the polls and the other party is larger than the

onepredicted by the polls only in closely divided electorates. We pro-

vide a behavioral model that explainsthe main findings of our exper-

imental and empirical analyses.

1INTRODUCTION

In large electorates, the probability of casting a pivotal vote is close to zero regardless of the actual distribution of

preferences. A poll pointing to an evenly split electorate,however, may affect voters'beliefs on the probability of cast-

ing a pivotal vote, and consequently,voters'turnout.1Indeed, a lively debate is being carried out in several countries

on whether or not polls affect electoral results. A fundamental difficulty when trying to empirically assess the causal

effect of public opinion polls on voters'turnout decisions is that of omitted variables. Severalfactors, like valence char-

acteristics of candidates and their chosen platforms, affect not only individuals'turnout but also public opinion polls.

1Inthe U.S. presidential elections of 2004, for example, individuals who supported Ralph Nader and resided in states where the election was predicted to be

closetraded their votes with John Kerry's supporters who lived in states where the election was expected to be lopsided in favor of one candidate. People who

traded votes felt that now their vote“really counted.” As related in votepair.org/stories: “I live in Utah. The most Republican state in the nation. I happen to

be a democratwho voted for Gore. My vote did not count because of the stupid electoral college. By swapping my vote, I can finally have my vote count for a

democrat.”

Journal of Public Economic Theory.2018;20:239–256. wileyonlinelibrary.com/journal/jpet c

2017 Wiley Periodicals,Inc. 239

240 KLOR AND WINTER

This paper analyzes experimentally and empirically the impact that the provisionof information on the electorate's

distributionof preferences has on voters'turnout.2Our experiment compares the subjects'decision to participate in an

election when theyknow the exact distribution of preferences of the electorate to their decisions when they only know

their own preferences. Our objectiveis to uncover any behavioral effects that the provision of information may have on

voters.Additionally, we collected, through a survey administered at the beginning and at the end of our experiment, the

subjects'estimated probabilities of casting a pivotal votefor all the different distributions of preferences. This allow us

to assess whether the subjects'behavior is a consequence of their beliefs or despite thereof.

The experimentalresults show that closeness in the division of preferences induces a significant increase in turnout.

This is consistent with results reported in the vast related empirical literature.3Perhaps, more surprisingly,in closely

divided electorates (and only for these electorates) the provision of information significantly raises the participation

of subjects supporting the slightly larger team relative to the smaller team. We refer to this behavior as the band-

wagon effect of polls. This behavior contradicts the qualitativepredictions of the unique quasi-symmetric equilibrium

of the theoretical model underlying the experiments. According to the equilibrium conditions, the provision of infor-

mation on the electorate's preferences should induce votersin the majority to participate less frequently because they

free ride on the voting of other individuals supporting the same alternative. At the same time, polls should stimulate

the participation of voters in the minority to offset the advantage of the other alternative. These requirements of the

mixed-strategyNash equilibrium seem counterintuitive and are not supported by the experimental data.4

To uncover the root causes behind the bandwagon effect of polls, we incorporateinto the analysis the subjects'

responses to the surveys. This analysis shows that the heterogeneous effect of information on subjects'turnout is

driven by the subjects'(incorrect) beliefs of casting a pivotal vote. Simply put, subjects overestimate the probability

of casting a pivotal vote when they belong to the team with a slight majority,and choose the strategy that maximizes

theirutility based on their inflated probability assessment. This conjecture was first formalized by Riker and Ordeshook

(1968). Tothe best of our knowledge, this paper is the first attempt to formally test this hypothesis.

The observed bandwagon effect of polls is consistent with previous experimental studies. While studying the inci-

dence of reform in the presence of individual-specific uncertainty, Cason and Mui (2005) find that the participation

rates of the majority are higher than the participation rates of the minority.Großer and Schram (2010) also conduct

an experimental study of the effects of information on turnout. In particular,they examine the welfare implications of

endogenous voter participation using a different experimental design that includes floating voters. Theyalso find that

the majority participates more than the minority but this difference is not statistically significant. Our experiment, like

that of Cason and Mui (2005), is especially designed to use the subjects as our unit of observation, granting us the pos-

sibility to differentiate between distributions with enough observations for each one to be able to perform statistically

tests.

Finally,Levine and Palfrey (2007) and Duffy and Tavits (2008) conduct direct experimentaltests of the predictions

of the pivotal voter model. Levineand Palfrey (2007) focus on the theoretical analysis of Palfrey and Rosenthal (1985),

wherebyparticipation costs are heterogeneous and privately known. They find that subjects in the small team vote with

higher frequency than subjects in the large team. Similar to our study,Duffy and Tavits (2008) focus on the theoretical

analysisof Palfrey and Rosenthal (1983), whereby participation costs are the same across all subjects. In addition, Duffy

and Tavits(2008) also elicit individuals'subjective beliefs of being pivotal and correlate these beliefs with individuals'

actions.

There are importantd ifferencesbetween our study and the studies above. Unlike our experimental design, the stud-

ies above do not directly test for the effects of the provision of information. Moreover,Levine and Palfrey (2007) and

Duffy and Tavits(2008) (as well as Großer & Schram, 2010) reveal the exact vote tally at the end of each round, thus

2SeeGoeree and Großer (2005) and Taylor and Yildirim (2010) for theoretical studies of the effects of information on the electorate's behavior.

3SeeBlais (2000), Feddersen (2004), and Merlo (2006) for surveys of the large existent literature on voters'turnout.

4A similar behavioraldeparture from mixed-strategy Nash equilibrium was documented by Rapoport, Seale, and Winter (2002) in an experimental study of

marketentry with asymmetric players.