Introduction

Over the last decade, ranked-choice voting has gone from the fringes to the mainstream of political reform. Generally, ranked-choice voting (RCV) is seen as a way to encourage more compromise and moderation in politics; to reduce negative campaigning; to introduce more competition within the two major parties; to end the spoiler effect of third party candidates; and to ensure majority winners without costly and low-turnout runoff elections. With largely successful use-cases in the 2021 New York City mayoral primary, in several Democratic Party presidential primaries in 2020, and in Maine elections in 2018 and 2020, RCV has entered the national conversation as a sensible and popular reform with momentum. In its single-winner form, it is also a relatively modest change to the current voting system, and thus, appears to be a relatively achievable victory for reformers.

With a growing number of RCV elections to draw on, considerable research has followed. The goal of this report is to provide a systematic overview of this research.

The broad conclusion of this report is that, while single-winner ranked-choice voting does have many positive effects both in theory and in overseas usage, in practice these benefits have been somewhat limited and/or difficult to quantify based on limited usage thus far in the United States. On balance, the benefits of RCV outweigh the downsides, and RCV has many appealing qualities that make it a strong improvement over more traditional single-mark plurality voting. However, the benefits appear to be more marginal than many had initially hoped. Certainly, it is possible that the research has failed to adequately capture the benefits, and that the benefits take time to become apparent as candidates and voters learn and attitudes change. It is also possible that nationwide adoption of RCV would be more transformative than city-by-city and even state-by-state adoption. But given the broader structural forces at play in our deteriorating national politics, stronger medicine may be needed.

The most notable benefits of ranked-choice voting so far concern campaign tone and descriptive representation. Research suggests elections with RCV are more civil, and less nasty, as proponents have argued; and what limited evidence we have on RCV and electoral outcomes suggests that the system does, as promised, increase the odds of candidates of color and women candidates being elected. Additionally, there is strong evidence that most citizens like using ranked-choice voting, and they find it easy and straightforward to use—especially once they experience the system in a real election. Though critics and skeptics have raised concerns about the ways in which RCV could confuse and potentially demobilize certain voters, those concerns appear unfounded at this point.

Still, both ease of use and enthusiasm for RCV vary among the population. Not surprisingly, age is a significant correlate of support, with young people more likely to embrace change and older people more likely to want to continue voting under the rules they have known for their entire lives, rather than having to learn something new. Also, Democrats tend to be more favorable toward RCV than Republicans. This may reflect the fact that conservatives are more averse to change, or that RCV is currently seen more like a Democratic reform than a Republican reform. However, since most voters do not have strong opinions either way, there is certainly room for this to change with appropriate grassroots movement building and elite signaling.

Additionally, RCV seems to work well in primaries, the elections where vote-splitting is most likely to be a problem and where extreme candidates are most likely to win with a small plurality. Another advantage of using RCV in primaries is that it combines well with voting by mail. Since candidates may drop out suddenly, mailed votes are not wasted if voters can indicate their back-up preferences. Certainly, the New York City Democratic primary of 2021 offers a success story of ranked-choice voting, despite some administrative blunders by the Board of Elections that had nothing to do with the reform itself.

Other impacts of ranked-choice voting are harder to observe. At this point, it is unclear whether the system has any consistent impacts on who votes, who runs, or how governing works. The lack of clear findings here may exist for a few reasons. First, a limited number of cities have implemented RCV, and these cities tend to be unique in various respects, which makes the kinds of comparisons needed to draw meaningful conclusions about broader implementation difficult. Second, it may take time for these downstream effects to show up as voters, candidates, and public officials learn and adjust to different rules. Third, and most likely, it may simply be the case that the single-winner form of RCV that most cities have implemented has only marginal impacts.

Again, the existing literature has its limits, and even this overview does not encompass the totality of studies on the effects of ranked-choice voting. Notably, this report’s deliberate focus on RCV in the United States leaves less room for discussion of RCV usage overseas, even as the international scholarship laid the groundwork for many of the domestic studies examined here. The report also does not account for the results of research currently underway to understand the effects of RCV in New York City’s 2021 primaries, nor the 2022 implementation of Alaska’s final-four open primaries with RCV in the general election. These limitations notwithstanding, many of the bolder claims about the transformative nature of ranked-choice voting are still purely hypothetical at this point.

Also known as preferential voting, instant runoff voting, the single transferable vote, and the alternative vote, ranked-choice voting describes a family of election methods in which voters use a ranked ballot to select multiple candidates in order of preference. The RCV family encompasses at least five distinct approaches to allocating votes capable of producing significantly different outcomes.¹ For the purposes of this report, however, we will focus mainly on the most used and studied versions of RCV: single-winner RCV (which we will call simply RCV), and a form of multi-winner RCV called the single-transferable vote, or STV.

RCV works as follows: voters rank candidates on the ballot in order of preference (first choice, second choice, third choice, etc.). If no candidate wins a majority of first-preference votes in the first round, the second choices from the candidate with the fewest first choices are counted. This process repeats until one candidate wins a majority. RCV is used to elect one person per contest, whether it is for a seat in a single-member legislative district or a singular office such as mayor or governor.

STV is a form of proportional representation used for electing representative bodies like city councils, legislatures, and school boards. Under STV, candidates are again ranked in order of preference, and those who receive a predetermined share of votes (also known as the “quota” or “threshold”) win seats. While the quota in a single-seat RCV race is always a simple majority (50 percent + 1), STV quotas depend on the number of seats up for election. The standard formula for calculating the quota is: (votes/(seats +1)) +1. Any candidates that meet the quota in the first round of voting are elected, and surplus votes (votes beyond the amount they needed to win) are reallocated to voters’ next choice. If more candidates than seats remain after the first round, the lowest-ranked candidate is eliminated, and voters who ranked that candidate first have their votes transferred to their next choice. This process continues until all seats are filled. Though RCV and STV are not identical, they both use a ranked ballot, as opposed to the single-mark ballots to which Americans are accustomed.

Because single-winner RCV is the dominant form of RCV used in the United States, the vast majority of empirical studies focus on that form. However, a few studies examine multi-winner RCV, or STV, as well.

RCV was invented in the mid-nineteenth century, first as a form of proportional representation and later adapted to single-winner elections. Australia became the first country to adopt single-winner RCV for local and federal elections in the early 1900s and implemented STV for Senate elections in 1948. Other countries followed their lead. Today, in addition to Australia, RCV and/or STV are used today in national elections in Ireland, Malta, Papua New Guinea, and, increasingly, the United States, where both Maine and Alaska have now adopted RCV for use in federal elections. (Maine has used RCV twice, in 2018 and 2020; Alaska voted to adopt it in a 2020 referendum, and will use it for the first time in 2022.)

According to a recent count by FairVote, the country’s longest-running and most prominent RCV advocacy organization, 43 jurisdictions used some form of RCV in their most recent election. This includes 20 cities in Utah, which are using various forms of RCV as part of a temporary pilot program created by the state legislature. Even more places, including the state of Alaska, plan to use RCV in their next election.²

While different forms of RCV have been spreading quickly across the United States in recent years—inspiring hope among reformers and a wave of fresh research into the effects of electoral reform—this isn’t actually America’s first experience with RCV. As scholars such as Douglas J. Amy and Jack Santucci have chronicled in their research, America’s experience with RCV dates back to the late Progressive Era. Between 1912 and 1947, 11 states used RCV for statewide party primaries, and at least 24 cities adopted STV for municipal elections.³ Most of them repealed RCV and STV after the reforms resulted in more representation for political and racial minorities, spurring aggressive backlash from dominant party organizations in particular.⁴ Only two cities resisted repeal. To this day, Arden, Delaware, and Cambridge, Massachusetts, use STV for certain municipal elections.

Even though the promises of RCV often center on its potential moderating effects, most of the research has thus far focused on voter experiences and attitudes. Largely, this is because it is much easier to study voter attitudes and experiences than it is to study outcomes.

Ascribing policy outcomes to RCV (and voting systems in general) is difficult. Policy outcomes have many diffuse causes, and the choice to switch to RCV is not a random event—it happens in a specific political context that makes certain policy outcomes more or less likely regardless of what voting rules are in effect. Single-winner ranked-choice voting is also a relatively small voting system change. All this makes it difficult to conclude anything definitive about the reform's downstream effects.

By contrast, surveys and even lab experiments are relatively straightforward to conduct, and likely to yield publishable findings; voting data is relatively straightforward to obtain and analyze. This does not mean such findings are any less valuable, of course. No matter how good RCV might seem in theory, if it proves overly confusing, discriminatory, unfair, or otherwise problematic in usage, it is not a very good voting system. As a baseline, any voting system must not place unreasonable burdens on voters, or lead them to make perverse choices because they do not understand the implications of their votes.

The good news is that, on balance, citizens find RCV easy to use, enjoy using it, and use it successfully. Attitudes and behavior vary among voters, with some groups using it and liking it more than others. Younger people like it more than older people, for example.⁵ But the overarching conclusion is that once people get used to ranking (typically after a single election), it becomes normal and preferable to voters. And indeed, polling from cities that implement RCV consistently shows that voters in those cities support the continued use of RCV.

After the voting experience, the second aspect of any electoral reform is whether it changes the types of candidates who run and how they campaign. RCV advocates argue that ranked-choice voting elections reduce negative campaigning because of the way that ranking alters incentives, making the “lesser-of-two-evils” strategy less useful and therefore less likely. As a result, a kindler, gentler form of campaigning may attract the kinds of bridge-building candidates who might otherwise think running for office is not for them. Several studies have explored the effects of RCV on who runs and how they campaign, with some modest support for the claim that RCV elections attract more diverse candidates (from different parties, demographic backgrounds, and social groups) and induce less negative campaigning. Still, more scholarship on this is needed.

A third measure of interest for any electoral reform is whether it changes the types of candidates who win. In theory, ranked-choice voting should lead not only to more diversity among candidates, but among winners as well. Under RCV, we should expect to see more moderate or consensus-oriented winners. This should reduce polarization as candidates are encouraged to appeal more broadly and build coalitions. RCV should also lead to winners from third parties, independents, and historically underrepresented demographic groups. Currently, we lack sufficient data to confirm these theories as they relate to moderates, independents, and third parties, though the growing usage of RCV in primaries may provide some better evidence. On the other hand, available data supports the claim that RCV leads to more BIPOC and female winners.

A fourth aspect of any electoral reform is whether it changes policy and governing outcomes. Again, this is an especially tricky area to study, given the wide variety of factors that affect how policy is made and government functions, and the extent to which ranked-choice voting in the United States has been implemented at the municipal level.

These four aspects of electoral reform—how the reform affects the voting experience (“who votes, and how do voters experience the process?”), candidates and campaigns (“who runs, and how?”), electoral outcomes (“who wins?”), and policy and governance (“what happens then?”)—provide the structure for the following review of the ranked-choice voting scholarship. Within these four main sections we test 12 specific claims that RCV advocates have made against the available research, and offer summary conclusions and future research recommendations for each one. Toward the end of the report, we also briefly address questions regarding the costs of administering and running in a ranked-choice voting election. Finally, we consider how RCV works or could work in combination with other political reforms, such as nonpartisan primaries and multi-member districts, and suggest some avenues of future study.