Bayesian Polarization

2025/09/02 by Tuval Danenberg, Danenberg, Tuval
Computer Science · Decision Sciences · Physics and Astronomy · #FOS: Economics and business #Game Theory and Applications #Logic, Reasoning, and Knowledge #Opinion Dynamics and Social Influence #Theoretical Economics (econ.TH)

paper · pdf · doi:10.48550/arxiv.2509.02513

openalex publication_date 2025/09/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Discussions of political disagreement emphasize two patterns: polarization, where beliefs diverge toward opposite extremes on each issue dimension; and issue alignment, where individuals' views across issues become more internally consistent. We show that both can simultaneously arise under Bayesian learning from public information. We characterize the public signals that can induce persistent polarization on all dimensions and find that evidence of issue alignment can polarize Bayesian agents. However, we show that even stronger notions of polarization, requiring divergence beyond marginal beliefs, are inconsistent with Bayesian rationality. Whether multidimensional belief polarization translates into divergent aggregate positions depends on cross-issue separability.

Citations

• Similarity of Information and Collective Action
• A detailed treatment of Doob's theorem
• Bias in Cable News: Persuasion and Polarization
• Is Polarization a Myth?
• The nature of belief systems in mass publics (1964)
• Have American's Social Attitudes Become More Polarized?
• Mass Polarization: Manifestations and Measurements

Related

• Polarization in Geometric Opinion Dynamics
• A Multi-Agent Model for Polarization under Confirmation Bias in Social Networks
• Polarization and Belief Convergence of Agents in Strongly-Connected\n Influence Graphs
• A Polarization Opinion Model Inspired by Bounded Confidence Communications
• Paths to Polarization: How Extreme Views, Miscommunication, and Random Chance Drive Opinion Dynamics