Does vote buying undermine confidence in ballot secrecy? Theory and experimental evidence

Why does vote buying persist under the secret ballot? We argue initiating vote-buying transactions allows politicians to undermine voter confidence in the secret ballot, and thus to induce voter compliance. Our analysis consists of three parts. First, we present evidence from a survey experiment in Mexico that shows receiving material goods from a candidate diminishes voter confidence in ballot integrity. Next, we introduce an informational theory of vote buying that explains this phenomenon. Specifically, we develop a model of vote buying as a signaling game, in which a voter who is ex ante uncertain about a politician's capacity to monitor voter behavior learns new information from the politician's actions. Finally, we test the key insights from the model in a lab experiment. Our results suggest that, under certain conditions, offering material goods to voters is sufficient to erode their confidence in ballot secrecy, making vote buying effective.