Communication and voting in heterogeneous committees : an experimental study

We study experimentally the effectiveness of communication in common value committees exhibiting publicly known heterogeneous biases. We test models assuming respectively self-interested and strategic-, joint payoff-maximizing- and cognitively heterogeneous agents. These predict varying degrees of strategic communication. We use a 2 x 2 design varying the information protocol (communication vs exogenous public signals) and the group composition (heterogeneous vs homogeneous). Results are only consistent with the third model. Roughly 80% of (heuristic) subjects truth-tell and vote with the majority of announced signals. Remaining (sophisticated) agents lie strategically and approximately apply their optimal decision rule.