The Swing Voter's Curse in Social Networks

Abstract

We study private communication in social networks prior to a majority vote on two alternative policies. Some (or all) agents receive a private imperfect signal about which policy is correct. They can, but need not, recommend a policy to their neighbors in the social network prior to the vote. We show theoretically and empirically that communication can undermine efficiency of the vote and hence reduce welfare in a common interest setting. Both efficiency and existence of fully informative equilibria in which vote recommendations are always truthfully given and followed hinge on the structure of the communication network. If some voters have distinctly larger audiences than others, their neighbors should not follow their vote recommendation; however, they may do so in equilibrium. We test the model in a lab experiment and find strong support for the comparative-statics and, more generally, for the importance of the network structure for voting behavior.JEL-Code: D72, D83, D85, C91.

Voting with public information

“…Second, unlike in the obedient voting equilibrium in the current paper, in these models it is actually socially efficient for the agents to always follow the public information, conditional on their private information being credibly revealed in the deliberation stage. 3 Finally, there is a third strand of literature on committee design and optimal voting rules 3 Buechel and Mechtenberg (2016) is a recent exception that shows that pre-voting communication can actually impede efficient information aggregation within a common-interest setting. They consider a network model in which agents are heterogeneously informed, and each informed agent can privately make a voting recommendation to the uninformed agents that are connected to her.…”

Persuading Strategic Voters

“…14 There are empirical studies on the swing voter's curse such as Battaglini et al (2010) and Grosser and Seebauer (2016). For a both theoretical and empirical approach on the swing voter's curse in the context of communication with experts, see Buechel and Mechtenberg (2019). restrict attention to straightforward communication strategies and then find the optimal communication strategy.…”

Social Groups and the Effectiveness of Protests

“…This literature aims at studying with laboratory experiments whether elections aggregate information as predicted in the Condorcet Jury Theorem and related results. This literature has been recently extended to allow for preplay communication of voters in networks by Buechel and Mechtenberg [2019] and Pogorelskiy and Shum [2019]. Compared to these papers, we consider simpler social networks and communication mechanisms in the networks, but we study information aggregation in a di¤erent and more complex setting in which a decision is not determined by a voting rule, but by a policy-maker without commitment.…”