How does RCV compare to delayed runoff and top-two systems?

Delayed runoffs and top-two elections offer some advantages over plurality voting, but they limit our options in the voting booth, fail to adequately curb the spoiler effect, exacerbate negative campaigning, and in the case of delayed runoffs, escalate administrative costs and reduce voter turnout.

In a delayed runoff system, if no candidate receives a majority of the vote in the general election, another election is held at a later date between the two highest vote-getters — a costly and burdensome affair for all involved. That additional election requires new ballots, more poll workers, and reconfiguration of the voting equipment, roughly doubling total administrative costs. The two finalists must also raise money twice, potentially increasing their reliance on wealthy donors. Most importantly, runoffs often see sharp drops in turnout, because many voters cannot afford to take additional time away from work, school, or family to make another trip to the polls. By conducting “instant runoffs” from a single ballot instead, RCV elects majority winners with a much higher average share of the first round vote than delayed runoffs do.

The “top-two” system turns the general election itself into a runoff. Under top-two, all candidates (regardless of political party) compete in a single primary, and the two highest vote-getters face off in the general, even if they are from the same party. Since it does not increase the number of elections, top-two avoids the higher costs and lower turnouts of delayed runoffs. On the downside, if multiple candidates from the same party run, they can split the vote such that none of them reach the general election. In the 2012 top-two primary in California’s 31st Congressional district, a district where registered Democrats outnumber Republicans, four Democratic candidates split the vote so that none of them made the general election. Republicans have frequently been shut out of top-two general elections in California as well, including from high profile contests like the 2016 and 2018 US Senate races. The threat of vote-splitting has led parties to pressure some candidates to not run at all, a clearly anti-democratic maneuver.

The “too many candidates” problem illustrates how the spoiler effect still looms large under both delayed runoff and top-two. Sometimes the vote-splitting is so bad that the the two highest vote-getters don’t even have 50% combined, as happened in the 8th district of California in 2012, where no candidate topped 16% in the primary. The vast majority voted for someone else to compete in the general. Here in Massachusetts, where our city elections use top-two, we’ve seen the same problem. In the 2013 preliminary election for Boston mayor, for example, the two finalists received only 35% combined. Importantly, if our cities adopted RCV, not only would they ensure fairer results, they would also eliminate their costly preliminary elections by finding a majority winner from a single ranked ballot.

While delayed runoffs and top-two do elect winners with a majority of the vote, they attain this laudable goal in a crude fashion. Unlike RCV, which welcomes new voices and choices into our elections, delayed runoffs and top-two find a majority by depriving voters of voices and choices in the final, decisive race, thereby limiting the range of political debate. They also set up head-to-head, negative slugfests that are alienating and divisive, as opposed to the more civil, engaging campaigns that emerge under RCV when candidates have to reach beyond their base to build majority support. Democracy is better served by having more voices and choices in our elections, not an arbitrary limit of two.

Further reading:
Fix the Top Two Primary: Admirable Goals Don't Justify Indefensible Outcomes
What's the Matter with California Turnout
Ranked choice voting outperforms runoffs in upholding majority rule