Communication in bargaining games with unanimity

Communication has been shown to increase proposer power in multilateral bargaining settings that use majority voting rule via competition between non-proposers for a place in the coalition. In this paper we investigate whether communication affects bargaining outcomes and the bargaining process in settings in which the competition effect is not present. We study committees that use unanimity rule to pass allocations. We find that in these settings, communication has the complete opposite effect compared with the majority settings: under unanimity, communication eliminates the inefficiencies that are present in settings without communication and it shifts bargaining outcomes towards egalitarian allocations with no proposer power. Communication logs provide insights regarding the topics subjects discuss and communication content correlates with bargaining outcomes.