Spatial Equilibrium with Entry
研究当现有政党竞争性选择纲领并理性预期到追求选票最大化的第三方进入时，政治竞争中的空间均衡。均衡结果与霍特林“中位数”均衡显著不同，现有政党在空间上分离，第三方通常输掉选举，这为两党制的稳定性提供了理论解释。
This paper examines spatial equilibrium in political competition when established parties choose their platforms competitively while rationally anticipating entry of a vote-maximizing third party. The resulting equilibrium is substantially different from the Hotelling "median" equilibrium. Established parties are spatially separated and third parties will generally lose the election. This provides one theoretical explanation for the stability of two-party systems. Namely that non-cooperative behavior between established parties can effectively prevent third parties from winning.