Does RCV represent all voters' choices?

Answer

This is accomplished by what's called the “threshold of election”, which is the percentage of votes required for a candidate to be elected. The threshold is determined by how many members are being chosen. If three seats are being filled, the threshold of election is 25 percent plus one vote (25% + 1 vote x 3 members = 75% + 3 votes). It's the smallest number of votes that three candidates can get but four candidates cannot.

In a four-member election, the threshold would be 20 percent plus one (20% + 1 vote x 4 members = 80% + 4 votes). It's the smallest number that four candidates can get but five cannot. In a nine-member election, such as in Cambridge, the threshold is 10 percent plus one (10% + 1 vote x 9 members = 90% + 9 votes). It's what nine candidates can get but 10 cannot.

 Being elected with 10 percent of the vote may not seem like “majority rule.” But if there were one majority winner from each of nine single districts, each representative would have been elected by a very small percentage of the total vote. Say each district has 1,000 voters, and each winner gets 51%, they would each have less than six percent of the citywide vote. (1,000 votes x 51% = 510 votes / 9000 citywide votes = 5.7%.)

Further, the voters of each district would either be winners or losers; represented or, at least feeling, unrepresented. And whether you were destined to be a winner or loser would largely depend on where you lived and where the district lines were drawn.

With multi-winner RCV, voters can rank their preferred candidates and at least some of their preferences are likely to be elected. If your favorite candidate receives the least support that candidate is “eliminated,” but your ballot is then counted for your next choice. Every voter has a fair shot of their vote helping to elect someone until all their preferences are either elected or eliminated.

If your favorite candidate exceeds the threshold, any "extra" votes are counted for the next choices on their ballots, in proportion to the size of the "surplus." Your ballot continues to support your top choices until all your preferences are elected or eliminated.