NoteMixed equilibria in runoff elections

We demonstrate that the Hotelling-Downs model with runoff voting always admits symmetric mixed strategy equilibria for any (even or odd) number of office-motivated candidates (provided they are at least four). In specific, (a) we show that the game does not admit any symmetric atomless equilibrium, (b) we fully characterize a class of symmetric atomic mixed equilibria which exist for any distribution of the voters' ideal policies and (c) we argue that these equilibria are more robust than pure strategy equilibria to introduction of uncertainty about the voters' preferences.