Ambiguity in electoral competition

The paper proposes an explanation to why electoral competition induces parties to state ambiguous platforms even if voters dislike ambiguity. A platform is ambiguous if different voters may interpret it as different policy proposals. An ambiguous platform puts more or less emphasis on alternative policies so that it is more or less easily interpreted as one policy or the other. I suppose that a party can monitor exactly this platform design but cannot target its communications to individuals one by one. Each individual votes according to her understanding of the parties' platforms but dislikes ambiguity. It is shown that this electoral competition has no Nash equilibrium. Nevertheless its max-min strategies are the optimal strategies of the Downsian game in mixed strategies. Furthermore, if parties behave prudently enough and if the voters aversion to ambiguity is small enough, these strategies do form an equilibrium. © Springer-Verlag 2006.