Using Voter-Choice Modeling to Plan the Final Campaign in Runoff Elections

Even though runoff elections are one of the most (if not the most) common forms of presidential elections in the world, voter-choice behavior in these two-round elections has been rarely researched. Two-round elections provide unique opportunities for both political analyst and consultant. They allow political analysts to apply their voter-choice models to actual voting behavior, rather than voting intentions, on a multi-party election on the first round, and validate their predictions on a two-party election in the final round. They provide political consultants and candidates with rich and factual data on voter preferences, revealed through the voting behavior observed in the first round, which can guide the planning and implementation of their final campaign. We use results from the four most recent Brazilian presidential elections to demonstrate how voter-choice models can be applied to guide the political campaign in runoff elections. First, we apply a first-order Markov model to the two rounds and show that the two surviving candidates from the first round must focus their attention towards the voters for the eliminated candidates in the second round. We then apply a voter-choice model to the results from the first round in the most recent election (2014) to demonstrate how the political analyst and consultant can use the vote counts observed in the first round to better deploy the remaining campaign resources for the second round during the short time left before the final vote