Corruption in Committees: An Experimental Study of Information Aggregation through Voting

• Published date: 01 August 2015
• Date: 01 August 2015
• Author: JEAN‐ROBERT TYRAN,REBECCA B. MORTON
• DOI: http://doi.org/10.1111/jpet.12153

CORRUPTION IN COMMITTEES:ANEXPERIMENTAL STUDY

OF INFORMATION AGGREGATION THROUGH VOTING

REBECCA B. MORTON

NYU NYC and NYU Abu Dhabi

JEAN-ROBERT TYRAN

University of Vienna and University of Copenhagen

Abstract

We investigate experimentally the effects of corrupt experts

on information aggregation in committees. We find that

nonexperts are significantly less likely to delegate through

abstention when there is a probability that experts are cor-

rupt. Such decreased abstention, when the probability of

corrupt experts is low, actually increases information effi-

ciency in committee decision-making. However, if the prob-

ability of corrupt experts is large, the effect is not sufficient

to offset the mechanical effect of decreased information ef-

ficiency due to corrupt experts. Our results demonstrate

that the norm of “letting the expert decide” in committee

voting is influenced by the probability of corrupt experts,

and that influence can have, to a limited extent, a positive

effect on information efficiency.

1. Introduction

Individuals often vote in situations where they have less than perfect infor-

mation about the choices before them. Moreover, information is typically

Rebecca B. Morton, Department of Politics, NYU NYC and NYU Abu Dhabi, 19 West 4th

Street, 2nd Floor,New York, NY 10012 (rebecca.morton@nyu.edu). Jean-Robert Tyran, De-

partment of Economics, University of Vienna, Oskar-Morgenstern-Platz 1, 1090 Vienna,

Austria; Department of Economics, University of Copenhagen, Øster Farimagsgade 5,

1353, Copenhagen, Denmark (jean-robert.tyran@univie.ac.at).

We appreciate greatly the excellent research support of Michael Rudy Schrøder, Lars

Markan Reenberg, Nils Bruhn Christensen, Florian Spitzer, and Marco Piovesan. We also

have benefitted from the comments of Antonio Nicolo and other participants at the Work-

shop on Governance and Political Economy hosted at the Myra School of Business in

December, 2012. We thank the Austrian Science Foundation for financial support under

project number FWF S10307-G16.

Received April 12, 2013; Accepted March 3, 2015.

C2015 Wiley Periodicals, Inc.

Journal of Public Economic Theory, 17 (4), 2015, pp. 553–579. 553

554 Journal of Public Economic Theory

asymmetrically distributed, where some voters have better knowledge about

the choices than others. In a common interest situation one norm is to del-

egate to the so-called experts, the individuals who are known to have better

information. However, suppose that there is a possibility that the expert is

biased, either because she has private preferences independent of her infor-

mation or due to corruption. At what point should an individual who has less

information cease to delegate decision-making and participate in the choice

process as well, even though they know that given the poor quality of their

own information, they may be making the wrong choice?

In this paper, we consider experimental voting games in which individ-

uals face this dilemma. Information asymmetries can be particularly prob-

lematic in voting. That is, the only time that an individual’s vote matters is

when that vote is pivotal, either forces a tie or breaks a tie. But if an indi-

vidual is uninformed or has substantially less information than other voters,

then a pivotal vote may mean canceling out the vote of a more informed

voter. If both voters have the same underlying preferences (i.e., would make

the same choices if fully informed), the uninformed voter’s participation has

resulted in a worse outcome. Feddersen and Pesendorfer (1996, 1999), in

a seminal set of papers, pointed out that voters with low information levels

should avoid this “swing voter’s curse” and rationally abstain, delegating the

choice to fully informed voters. Battaglini, Morton, and Palfrey (2008, 2010)

find support for such “delegation through abstention.”

However, abstention is not necessarily the best response of less informed

voters if none of the voters has full information. As Morton and Tyran (2011)

show, when no voter is fully informed equilibria also exist in which all voters

participate even though they differ in the quality of their information. When

the difference in information qualities is large, then equilibria with absten-

tion by those who have lower level information are informationally efficient.

But when the difference in information qualities is small, equilibria in which

all voters participate are informationally efficient. Using experiments, Mor-

ton and Tyran show that the equilibria with delegation through abstention

are attractive to voters. Even when it is informationally efficient for all voters

to participate, about half the time less informed voters abstain, delegating

the decision to more informed voters. Thus, they find that individuals are

strongly inclined to “let the experts decide” when voting.

In these experiments a common interest situation prevailed. That is, if all

voters were fully informed they would agree and make the same decision. A

more realistic situation is when some voters will choose to vote a certain way

independent of their information. For example, the voter may be “corrupt”

in the sense that she ignores what she knows is best given the information

she has, and always votes for an outcome preferred by some outside party.

In such a case even a voter with low information may find it optimal to par-

ticipate. If the direction of bias is known by uninformed voters, Feddersen

and Pesendorfer (1996, 1999) demonstrate that uninformed voters have an

incentive to vote to offset the known bias, so that unbiased informed voters