Entry deterrence in electoral spatial competition

In this paper we examine a model of electoral competition with entry costs, where several established parties compete against each other under the threat of potential entry. Assuming single-peakedness of the distribution of voters' ideal points, we show that, if there are two established parties, an equilibrium always exists and is unique, and demonstrate that the Hotelling-Downs and the Smithies-Palfrey equilibria represent special cases of the equilibrium in our model. If there are more than two established parties, an equilibrium is always unique and there exists an upper bound on the values of entry cost which guarantee the existence of an equilibrium. © Springer-Verlag 1998.