Communication as Voting

TL;DR

This paper studies a voting-like communication model with multiple noisy senders and a receiver, revealing that disagreement can hinder information aggregation and that mediators can improve efficiency.

Contribution

It introduces a model where senders and receiver may disagree, proving an equilibrium no-conflict result and showing how mediators can enhance information transmission.

Findings

In non-babbling equilibria, senders and receiver agree on the preferred policy.

Information aggregation fails even with many senders.

Mediators can improve information transmission and restore efficiency.

Abstract

This paper analyzes a cheap-talk model with multiple senders and one receiver. Each sender observes a noisy signal about an unknown state and sends a message; the receiver observes the message tally and chooses a policy. This setting shares certain features with voting models (e.g., Feddersen and Pesendorfer, 1997, 1998). The existing literature (e.g., Levit and Malenko, 2011; Battaglini, 2017) focuses on scenarios in which the receiver and the senders agree on the preferred policy in each state. In contrast, we explore environments in which the receiver and the senders disagree over the preferred policy in some states. We establish an equilibrium no-conflict result: in any non-babbling equilibrium, the senders and the receiver agree on the preferred policy at every realized message tally. We show that information aggregation fails, and the receiver cannot fully learn the state even as the number of senders grows large. We also identify a discontinuity in information transmission relative to the implications of the existing literature. Finally, introducing a mediator can improve information transmission and restore efficiency.