It’s time once again to figure out Worcester’s weird voting system. There’s a preliminary election September 8, 2015, and a general election November 3, 2015. In the For both the School Committee and at-large City Council elections, you get six votes, and the six candidates with the most votes win. This is called “plurality-at-large voting.” In a situation like this, the study of game theory has some ideas on how to put your vote to best use, depending on much you know or care about the election.
If there are candidates you like, but you’re not sure what kind of chance they have, don’t worry about strategy. Just vote for who you like.
If you don’t know much about the election, but someone you trust wants you to join a larger group in voting for a slate of candidates, you should probably do it. That’s called “bloc voting” and it’s a great way to win elections. At the very least you know you’ll be voting for candidates you would probably like, and who probably have a chance.
If you know something about the mood of the electorate and the candidates, and you want to make up your own mind, the Myerson-Weber strategy puts the decision in mathematical terms, by helping you calculate a “prospective rating” for each candidate. To figure your “prospective rating” for a candidate, compare her with every other candidate. For each pair, consider how much more (or less) you like your candidate, and multiply that by how likely the two are to tie for a seat (the “pivot probability”). Add up the results of comparing a candidate with all the others, and you have your candidate’s “prospective rating.” Vote for the 6 candidates with the highest prospective ratings, and you’ve both done your civic duty and maximized your chances for a happy outcome, as proven by math.
Should you leave some of your votes blank? That’s called “bullet voting.” It’s a way to “send a message” that you couldn’t find 6 candidates worthy of your vote. But leaving spaces blank will only decrease your chances of being satisfied with the results. If you can find 6 candidates you even kinda like, you should vote all your votes, and have your fair share of influence on the election results.
Worcesterites do like bullet voting though: for the past few elections, about half the voters leave at least one vote blank, and the average has been between 3.8 and 4 votes per ballot, far short of all 6.
A note on the preliminary election: there are 16 candidates for City Council At-Large seats, and according to the rules that’s too many. So ever voter will get 6 votes, and the top 12 candidates will advance to the general election. In the general, the top 6 will be elected.
From the August 2015 issue of Happiness Pony.