The current RCV system also facilitated higher voter participation than the previous December runoff system, which San Francisco used until 2004. Under that system, the first election occurred in November, followed by a second race in December if no candidate won an initial majority. Voter turnout often plummeted in the December runoff, on average by 31 percent. In the 2001 runoff for city attorney, less than 17% of registered voters participated. In the 1995 mayoral election, the number of voters declined by nearly 10 percentage points from November to December.
Some have asked why San Francisco does not use the “plurality” voting method, in which the highest vote-getter wins. Plurality voting is used to elect many governors, senators, and the president. But if plurality had been used in our mayoral election, the winner would have been elected with less than 37% of the vote, with more than 60% of voters casting a ballot for another candidate. The goal of any runoff system is to ensure that the winner has a majority (50% + 1) of the vote and is the candidate preferred by the most voters. San Francisco’s “instant runoff” elections fulfill both goals, but without the expense—both for taxpayers and candidates—of a separate runoff election. San Francisco saves approximately $3.5 million by not holding a second citywide election.
Our RCV system also has allowed voters to choose from a more diverse candidate pool. Of the eighteen offices in San Francisco elected by RCV, thirteen are held by office-holders of color, a significantly higher proportion than before RCV implementation. One study found that the other Bay Area cities using RCV—Oakland, Berkeley and San Leandro—have seen similar results. A few years ago, Oakland elected its first-ever Asian-American woman as mayor, and San Francisco just elected an African-American female mayor.