We consider a proportional-prize contest to forecast future events, and show that, in equilibrium, this mechanism possesses perfect forecasting ability for any group size when the contestants share common knowledge about the probabilities by which future events realize. Data gathered in a laboratory experiment confirm the performance invariance to group size. By contrast, when realization probabilities are not common knowledge, there are some differences across group sizes. The mechanism operates marginally better with three or four compared to two players. However, this effect is mainly driven by players’ behavior rather than by differences in the beliefs they form about the realization probabilities.

我们考虑了一个比例奖竞赛来预测未来事件，并表明，在均衡情况下，当参赛者共享有关未来事件实现概率的共同知识时，该机制对任何团体规模都具有完美的预测能力。在实验室实验中收集的数据证实了性能对组大小的不变性。相比之下，当实现概率不是常识时，组大小之间存在一些差异。与两个玩家相比，该机制在三到四个玩家的情况下运行得更好。然而，这种影响主要是由玩家的行为驱动的，而不是由他们对实现概率形成的信念的差异驱动的。