Cooperative Initiative through Pre-Play Communication in One-Shot Games

This paper considers two games, a stag hunt and a prisoners' dilemma. Each game features non-binding, costless, and free-form pre-play communication. I focus on players who verbally first suggest cooperation in each game. I study experimentally whether the frequency of verbal initiative-taking for cooperation varies across games and whether initiative-taking induces cooperation in each game. In the stag hunt, I find that initiative-taking is ubiquitous and initiators cooperate more often than non-initiators. In the prisoners' dilemma, initiative-taking is less frequent relative to the stag hunt and initiators cooperate remarkably more often than non-initiators. In this case, initiators who cooperate are also more altruistic, averse to lying, and believe others are likely to cooperate compared to initiators who defect. Thus, initiating a suggestion to cooperate signals propensity to cooperate even when monetary incentives encourage defection. Moreover, optimistic and intrinsically motivated initiators are essential in attaining mutual cooperation when the (pecuniary) best response is to defect from it.