Communication is a well-known tool to promote cooperation and pro-social behavior. In this study, we examine whether minimal communication in form of public consent with a pre-defined cooperation statement is sufficient to strengthen cooperation in groups. Within the controlled environment of a laboratory experiment, we identify ways by which non-enforceable cooperation statements are associated with higher levels of cooperation in a public good setting. At first, the statement triggers selection; socially oriented individuals are more likely to make the cooperation statement. In addition, we can show that a behavioral change takes place once the statement is made. This change can be attributed to commitment arising from the pledge and to increased coordination between the interaction partners. Depending on the institutional context, these drivers can vary in strength. Comparing compulsory and voluntary cooperation statements, we find that both are effective in motivating higher contributions to the public good.

交流是促进合作和亲社会行为的众所周知的工具。在本研究中，我们研究了以预先同意的合作声明形式以公众同意的形式进行的最小限度的交流是否足以加强小组合作。在实验室实验的受控环境中，我们确定在公共物品环境中将不可执行的合作声明与更高层次的合作相关联的方式。首先，该语句触发选择；面向社会的个人更有可能发表合作声明。此外，我们可以证明，一旦做出声明，行为就会发生变化。这种变化可以归因于承诺产生的承诺以及互动伙伴之间加强的协调。根据机构情况，这些驱动器的强度可能会有所不同。比较强制性和自愿性合作声明，我们发现两者都可以有效地促进对公共物品的更多贡献。