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Information Aggregation in Elections

Paper Session

Saturday, Jan. 6, 2018 10:15 AM - 12:15 PM

Marriott Philadelphia Downtown, Meeting Room 413
Hosted By: Econometric Society
  • Chair: Marco Battaglini, Cornell University

The Perverse Politics of Polarization

S. Nageeb Ali
,
Pennsylvania State University
Maximilian Mihm
,
New York University Abu Dhabi
Lucas Siga
,
New York University Abu Dhabi

Abstract

Many policies, such as trade and immigration, bear important consequences for both the size and distribution of surplus. Oftentimes, people are asked to vote on these policies despite not being all that well-informed about the consequences. This paper studies the extent to which an electorate can aggregate information when voters anticipate that some may benefit from a policy reform at a cost borne by others. We show that information aggregation may fail: with high probability, the outcome chosen when voters are privately informed departs from the outcome when all information is public. We identify a form of ``negative correlation''---where voters treat good news for others as bad news for themselves---that is necessary and sufficient for this informational failure. Commitments to post-policy redistribution can mitigate this inefficiency, and lead voters to select better policies. We characterize features of economic environments that may foster or preclude negative correlation. Our results offer an understanding of how information can amplify electoral status quo bias, or generate popular support for ill-advised reforms that are ex post regretted and subsequently reversed.

Full Information Equivalence in Large Elections

Paulo Barelli
,
University of Rochester
Sourav Bhattacharya
,
Royal Holloway University of London
Lucas Siga
,
New York University Abu Dhabi

Abstract

We study the problem of aggregation of private information in common value elections with two or more alternatives and with general state and signal spaces. We provide general conditions on the environment ensuring existence of a sequence of equilibria of the voting game that eciently aggregates information as the population size grows to in nity. The conditions explore the geometry of partitions on the distributions over private signals induced by the common state-dependent utility of the voters. Such conditions are met generically when the signal space is rich enough relative to the state space, and fail
robustly when the state space is rich relative to the signal space.

Costly Advice, Protests and Nonbinding Voting

Mehmet Ekmekci
,
Boston College
Stephan Lauermann
,
University of Bonn

Abstract

We study a scenario in which a receiver is collecting non-binding advice for a binary decision from partially informed senders who can send binary messages. This reflects situations such as non-binding voting of shareholders on a management proposal, protests by citizens, and polls. Under complete information, the preferences of the receiver and the senders are aligned but there is a conflict of interest over the trade-off of Type I and Type II errors. Existing work shows that for many such situations, the bias prohibits the transmission of any information. Here, in contrast to this work, we consider a setting in which one of the messages is costly. For example, there are positive costs of voting but no costs of abstention. We show that responsive equilibrium which transmits informative advice exists. When there are many senders, with costly advice, the outcome is equivalent to the one under complete information. In our general model, we also allow for noise induced by other motives. With noise, participation in an election becomes a strategic complement, with citizens joining voices to overcome the noise and make their opinion heard. Thus, receiver obtains some useful information but not all information. Even when the population size is arbitrarily large information partially aggregates leading to indeterminacy in receiver's decisions.

Modes of Persuasion Toward Unanimous Consent

Arjada Bardhi
,
Northwestern University
Yingni Guo
,
Northwestern University

Abstract

A fully committed sender seeks to sway a collective adoption decision by multiple voters with correlated payoff states and heterogeneous thresh- olds of doubt through designing experiments. We characterize the sender- optimal policy under unanimity rule for two main persuasion modes. Under general persuasion, the sender makes the most demanding voters indifferent between decisions, while the more lenient voters strictly benefit from per- suasion. Under individual persuasion, the sender designates a subgroup of rubber-stampers, another of perfectly informed voters, and a third of par- tially informed voters. The most demanding voters are strategically accorded high-quality information. In contrast, under nonunanimous rules, general persuasion guarantees a sure adoption, while individual persuasion does not; voters prefer the latter due to the partial check they have on adoption.
Discussant(s)
Richard Van Weelden
,
University of Chicago
Alvaro Sandroni
,
Northwestern University
Attila Ambrus
,
Duke University
Ina Taneva
,
University of Edinburgh
JEL Classifications
  • D7 - Analysis of Collective Decision-Making