MICRO THEORY: Professor Jonathan Newton (Kyoto Institute of Economic Research)

When is a majority sufficient to persuade a population to adopt a convention?

We study a model of social coordination in which agents repeatedly decide whether to adopt a behavior. Agents form beliefs about population adoption rates through random sampling, update these beliefs in response to a planner’s signals, and best respond to their posteriors. The planner seeks to promote adoption via a threshold-based disclosure rule. We show that optimal disclosure initiates a dynamic feedback: successful persuasion increases the fraction of agents with persuadable beliefs, which in turn amplifies the effect of future persuasion. We characterize conditions under which, starting from any state where adoption already holds a simple majority, the planner can induce convergence to the full-adoption convention.