Evidence disclosure with heterogeneous priors

Abstract

We investigate an interesting type of equilibrium of a game where a collective decision is reached by aggregating the preferred alternatives of a group of Receivers. A Sender that cares about the collective decision must make efforts (not below a normative-minimum) to gather evidence relevant for the Receivers to gauge their preferred alternatives. Research efforts may be unsuccessful, which allows for strategic concealment. Each Receiver cares only about her preferred alternative so that the goal of the Sender is achieved by affecting the beliefs of a single representative Receiver (e.g., pivotal voter). Disagreement between the players about the best alternative is based solely on heterogeneous priors. The type of equilibrium that we study arises when the Sender and the representative Receiver agree based on their priors but disagree based on some evidence. In such situations, while unfavorable evidence is concealed always, both disclosure and concealment of favorable evidence may happen with positive probability. Interestingly, for sufficiently low normative-minimum efforts, there arises a continuum of equilibria in which the Sender discloses favorable evidence with higher probability.