When Is Shuttle Diplomacy Worth the Commute?: Information Sharing through Mediation

The authors study the conflict mediation problem, sometimes called "shuttle diplomacy," when the mediator acts as a go-between and must gather information from the disputants. In the context of a general model of information mediation, they show that the incentive that disputants have to lie to the mediator undoes any advantage that might be gained by adding communication with a third party. In fact, the main result shows that any equilibrium outcome that is achievable through mediation is also achievable as an equilibrium outcome of a game with unmediated preplay communication. This is true even when the mediator is allowed to have arbitrary preferences or biases. The authors then test their empirical prediction on dispute management efforts between 1937 and 1985. The analysis supports the hypothesis that information mediation has no effect in environments where the mediator has no independent source of information.