This paper develops a political-competition model in which platforms are partially binding: a candidate who implements a policy that is different from her platform must pay a cost of betrayal that increases with the size of the discrepancy. I also suppose that voters are uncertain about candidate preferences for policies. If voters believe that a candidate is likely to be extreme, there exists a semiseparating equilibrium: an extreme candidate mimics a moderate candidate with some probability, and with the remaining probability, he announces a platform that commits to the implementation of a more moderate policy. Although an extreme candidate will implement a more extreme policy than a moderate candidate in equilibrium, partial pooling ensures that voters prefer an extreme candidate who does not pretend to be moderate over an uncertain candidate announcing a moderate candidate's platform. As a result, a moderate candidate never has a higher probability of winning than an extreme one.
Keywords: Electoral Competition; Campaign Promise; Signaling Game
Views expressed in the paper are those of the authors and do not necessarily reflect those of the Bank of Japan or Institute for Monetary and Economic Studies.