Communication and voting in heterogeneous committees: An experimental study

Abstract

We study experimentally the effectiveness of communication in common value committees exhibiting publicly known heterogeneous preferences and test whether social preferences or cognitive constraints drive the (non-)existence of strategic communication. As prior communication may affect voting decisions, we separately and jointly test communication and voting choices and how they depend on the presence of heterogeneous preferences. Results are only consistent with a model of cognitive heterogeneity. Roughly 80% of subjects truth-tell and use a decision heuristic (i.e. vote with the majority of announced signals). The remaining sophisticated agents lie strategically and approximately apply their optimal decision rule.

Deliberation and epistemic democracy

“…The social psychology literature on deliberation also typically assumes agents are honest and do not strategically withhold information (Adamowicz et al, 2005;Kerr and Tindale, 2004;Tindale and Kluwe, 2015). Recent experimental investiga-tion of deliberation in laboratory settings shows that agents publicly and truthfully reveal their private information at a much higher rate than what is predicted by the models of strategic deliberation described above (Goeree and Yariv, 2011;Le Quement and Marcin, 2019); this is consistent with our assumption that agents deliberate in "good faith". In the experimental design of Dickson et al (2008), agents exchange reasons rather than information (similar to the model of Hafer and Landa (2007)).…”

“…But it may be a good approximation for some juries and scientific committees. As already noted at the end of Section 5, nonstrategic communication is also assumed in most of the literature on opinion dynamics and rational learning in social networks, and most of the social psychology literature on deliberation, and confirmed by the experimental results of Goeree and Yariv (2011) and Le Quement and Marcin (2019).…”

“…Stasser et al (1995a) and Stewart and Stasser (1995b) conducted deliberation experiments in which some deliberators were assigned the role of "expert" analogous to the "informed" agents of Section 3. We have already mentioned the papers by Dickson et al (2008Dickson et al ( , 2015, Goeree and Yariv (2011) and Le Quement and Marcin (2019). Finally, Van Dijk et al (2014) present an experimental study of judicial decision-making in small groups, which shows that aggregation and deliberation both improve the reliability of group decisions -especially in difficult borderline cases.…”