under their ideology but for the center party's candidate, which caused major turmoil.) After a recount and a trial, Acevedo Vilá was certified as governor of the Commonwealth of Puerto Rico. Rational voter model Academic analysis of strategic voting is based on the rational voter model, derived from rational choice theory. In this model, voters are short-term instrumentally rational. That is, voters are only voting in order to make an impact on one election at a time (not, say, to build the political party for next election); voters have a set of sincere preferences, or utility rankings, by which to rate candidates; voters have some knowledge of each other's preferences; and voters understand how best to use strategic voting to their advantage. The extent to which this model resembles real-life elections is the subject of considerable academic debate. Myerson–Weber strategy An example of a rational voter strategy is described by Myerson and Weber. The strategy is broadly applicable to a number of single-winner voting methods that are additive point methods, such as Plurality, Borda, Approval, and Range. The strategy is optimal in the sense that the strategy will maximize the voter's expected utility when the number of voters is sufficiently large. This rational voter model assumes that the voter's utility of the election result is dependent only on which candidate wins and not on any other aspect of the election, for example showing support for a losing candidate in the vote tallies. The model also assumes the voter chooses how to vote individually and not in collaboration with other voters. Given a set of k candidates and a voter let: vi = the number of points to be voted for candidate i ui = the voter's gain in utility if candidate i wins the election pij = the (voter's perceived) pivot probability that candidates i and j will be tied for the most total points to win the election. Then the voter's prospective rating for a candidate i is defined as: The gain in expected utility for a given vote is given by: The gain in expected utility can be maximized by choosing a vote with suitable values of vi, depending on the voting method and the voter's prospective ratings for each candidate. For specific voting methods, the gain can be maximized using the following rules: Plurality: Vote for the candidate with the highest prospective rating. This is to be