An informed sender communicates with an uninformed receiver through a sequence of uninformed mediators; agents' utilities depend on receiver's action and the state. For any number of mediators, the sender's optimal value is characterized. For one mediator, the characterization has a geometric meaning of constrained concavification of sender's utility, optimal persuasion requires the same number of signals as without mediators, and the presence of the mediator is never profitable for the sender. Surprisingly, the second mediator may improve the value but optimal persuasion may require more signals.

翻译：知情的发送者通过一系列不知情的调解人与不知情的接收者进行沟通;代理商的公用事业取决于接收者的行动和国家;对于任何数目的调解人来说,发送者的最佳价值都有特点;对于一名调解人来说,定性具有约束发送者效用的精密化的几何含义,最佳说服要求的信号数量与没有调解人的信号相同,调解人的存在对发送者永远没有好处。 令人惊讶的是,第二名调解人可能提高价值,但最佳说服可能需要更多的信号。