Ranking Based Voting in Santa Fe
This article describes the situation for the mayoral election in Santa Fe. Next year, there will be an election for the mayor of Santa Fe. However, there are currently five candidates for the mayor position. The current voting system in Santa Fe, voters choose one candidate out of the list of five candidates. Recently, a judge has ordered that Santa Fe use a ranking based voting system in which voters ranked the candidates by their preferences. If no candidate has over 50% of rank 1 preferences, then rank 2 preferences are added to each candidate’s vote total.
This is a variation of the point-based preference voting system discussed in class. In this ranking based voting system, the vote is treated as a majority rules system if the winner gets more than 50% of the rank 1 votes. Consider an example with 3 candidates. If, for example, candidate X gets greater than 50% of the votes against 2 other candidates Y and Z, then it does not matter whether a voter would have picked X > Y > Z or X > Z > Y since the second or third rankings are never considered. If 30% of the population picked the first option above and 70% picked the second option above, then the group preferences are X > Y, Y >Z, and X > Z. In this scenario, the winner of the election is also reflected in the group preferences.
However, if instead, the 30% of the population picked X > Y >Z, 30% of the population picked Y > X > Z, and 40% of the population picked Z > Y > X, then the outcome is decided by the rank 2 preferences. In this scenario, the group preferences are that X > Z, Y > X, and Y > Z. In this scenario, Y is the winner of the election, and Y is also the candidate that is most preferred by the group preferences.
However, if instead of using ranked based voting, Santa Fe used a majority rules voting system, the election outcomes would not reflect the group preferences. Taking the example from the previous paragraph where 30% of the population picked X > Y >Z, 30% of the population picked Y > X > Z, and 40% of the population picked Z > Y > X would cause Z to be the winner of the election since only the rank 1 preferences matter. However, this result is the opposite of what the group preferences suggest, where Y > Z and X < Z. As a result, it is more likely that this election system will better represent the group preferences of Santa Fe’s population.