Affecting Distributions of Opinions with Evidence

We investigate evidence acquisition and disclosure by a communicator who cares about the distribution of the opinions of an audience. Uncertainty about whether evidence can be obtained allows for selective disclosure. We consider two alternativemotivations for the communicator: (i) to shift the average opinion towards her preferred one and (ii) to raise the dispersion of opinions. Under general structures for evidence provision, we characterize the unique equilibrium disclosure strategy for both motivations. The communicator’s return in equilibrium is linear in a measure of the extent to which the evidence-provision structure could favor her preferred state conditional on a given obtained piece of evidence. In this context, we analyze how certain features of the evidence-provision structure and of the distribution of initial opinions of the audience influence the communicator’s return. The relation between thewelfare of the audience and the acquisition effort depends critically on which of the two motivations yields higher returns to the communicator, an insight useful for policy recommendations. Minimum limits on evidence acquisition benefit audiences only when communicators seek to raise the dispersion of opinions, not when they seek to shift the average opinion.