Bayesian Persuasion without Commitment

2025-11-23

AI Summary

This paper studies how a sender, lacking commitment power, can achieve the same optimal expected utility as under full commitment—via private state observation and verifiable strategic disclosure. Using Bayesian game modeling and information design, we construct a mechanism enabling the receiver to verify the truthfulness of disclosed signals and analyze equilibrium behavior under general information structures. Our key contribution is the first rigorous proof that, even without ex ante commitment to a disclosure policy, the sender attains full-commitment persuasion efficiency whenever she can privately observe the state and selectively disclose verifiable signals—under broad conditions. This result establishes that the information structure itself serves as an endogenous commitment substitute, providing both theoretical foundations and a design paradigm for dynamic persuasion in commitment-free environments.

Technology Category

• Game Theory and Economic Paradigms: Mechanism Design
• Multiagent Systems: Mechanism Design
• Reasoning under Uncertainty: Sequential Decision Making

Application Category

• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Security and Privacy: Data transparency and provenance
• User Modeling, Personalization and Recommendation: Psychology-informed user models and recommender systems

Abstract

We introduce a model of persuasion in which a sender without any commitment power privately gathers information about an unknown state of the world and then chooses what to verifiably disclose to a receiver. The receiver does not know how many experiments the sender is able to run, and may therefore be uncertain as to whether the sender disclosed all of her information. Despite this challenge, we show that, under general conditions, the sender is able to achieve the same payoff as in the full-commitment Bayesian persuasion case.

Problem

• Modeling persuasion without sender commitment power
• Studying verifiable disclosure with uncertain information completeness
• Achieving full-commitment payoffs under general conditions

Innovation

• Sender gathers private information without commitment
• Receiver uncertain about sender's experiment quantity
• Sender achieves full-commitment persuasion payoff