What is Ranked Choice Voting (RCV), and how does it differ from traditional voting methods?

Ranked Choice Voting (RCV) is an electoral system where voters rank candidates in order of preference, unlike traditional methods where voters simply choose one candidate. The outcome in RCV is determined through a series of eliminations and vote transfers. This process continues until a candidate secures a majority of the votes. This approach aims to provide a more nuanced reflection of voter preferences and potentially elect candidates with broader support, but it can also lead to unexpected outcomes as described in the article.

What is a Monotonicity Paradox in the context of Ranked Choice Voting?

A Monotonicity Paradox in Ranked Choice Voting occurs when changes in voter preferences that would seem to benefit a candidate paradoxically lead to a worse outcome for that candidate. This is counterintuitive because we generally expect more support to translate into a better chance of winning. Several types of monotonicity paradoxes exist, including the Upward and Downward Monotonicity Paradoxes, and the Committee Size Paradox.

Can you explain the Upward Monotonicity Paradox in the context of the article?

The Upward Monotonicity Paradox occurs when a winning candidate loses after receiving more first-preference votes. This means that an increase in support, measured by the number of voters ranking the candidate first, results in the candidate losing the election. This outcome directly contradicts the fundamental expectation that more votes should improve a candidate's chances of winning.

What are the implications of the No-Show Paradox in Ranked Choice Voting?

The No-Show Paradox, also known as the Abstention Paradox, is where voters who support a candidate would have achieved a better outcome if they had abstained from voting. This means that by participating in the election and expressing their preferences, these voters inadvertently caused their preferred candidate to lose. This paradox highlights the complexity of RCV and suggests that even with honest and informed participation, the outcome might not always align with the voters' intentions.

Maze of ballots representing ranked choice voting paradoxes.

Ranked Choice Voting: When More Support Leads to Worse Outcomes

Q: Does the existence of paradoxes mean that Ranked Choice Voting is a bad system?

No, the existence of paradoxes doesn't automatically invalidate Ranked Choice Voting (RCV). The Scottish elections highlight potential flaws, but all systems have quirks and potential for unintended consequences. Understanding these limitations is crucial for informed decision-making and for designing election systems that best serve the needs of voters. The existence of paradoxes should be seen as a reminder that all voting systems have their limitations, and that the goal is to choose the system that best balances fairness, representativeness, and practicality, given the specific context and goals of the election.

Kai Mendoza in Politics & Policy September 2025 • 4 min read.

"Explore the surprising paradoxes in ranked choice voting systems where gaining more votes can lead to unexpected and undesirable results."

In the realm of elections, the idea that more voter support equates to a better outcome for a candidate seems almost axiomatic. It's the driving force behind campaign strategies, get-out-the-vote initiatives, and the relentless pursuit of endorsements. However, the world of ranked-choice voting (RCV) occasionally throws a wrench into this seemingly logical equation. In RCV, voters rank candidates in order of preference, and the outcome is determined through a series of eliminations and vote transfers. But what happens when gaining more support actually hurts a candidate's chances?

Researchers have long explored theoretical examples of such 'monotonicity paradoxes,' where an increase in votes paradoxically leads to a less favorable result. While these theoretical models are insightful, real-world examples have been scarce and often limited to single-winner elections. A new study, however, delves into the complexities of multi-winner elections in Scotland, uncovering instances where these voting paradoxes manifest in tangible and consequential ways.

This article will journey into the fascinating world of RCV anomalies, exploring the specific types of paradoxes that can arise and examining real-world case studies from Scottish local government elections. By understanding these counterintuitive outcomes, we can better assess the strengths and weaknesses of ranked-choice voting and its implications for fair and representative democracy.

Understanding Monotonicity Paradoxes in Ranked Choice Voting

Maze of ballots representing ranked choice voting paradoxes.

Monotonicity paradoxes occur when changes in voter preferences that appear to favor a candidate actually lead to a worse outcome for that candidate. These paradoxes challenge our intuitive understanding of how elections should function and raise questions about the fairness and representativeness of different voting systems. There are several types of monotonicity paradoxes:

Committee Size Paradox: This paradox occurs when a candidate wins an election for one committee size but loses when the number of available seats changes. For example, a candidate might win a single-seat election but fail to secure a spot when multiple seats are up for grabs, even though the underlying voter preferences remain the same. This can create a situation where the 'best' single candidate is not considered among the 'top half' when more positions are available.

Upward Monotonicity Paradox: A winning candidate loses after receiving more first-preference votes.
Downward Monotonicity Paradox: A losing candidate wins after receiving fewer first-preference votes.
No-Show Paradox (or Abstention Paradox): Voters who support a candidate would have achieved a better outcome if they had abstained from voting.

These paradoxes highlight the intricate and sometimes unpredictable nature of ranked-choice voting. While RCV aims to provide a more nuanced reflection of voter preferences, it is not immune to producing outcomes that defy conventional expectations of fairness and proportionality.

The Implications for Ranked Choice Voting

While the Scottish elections highlight potential flaws in ranked-choice voting, they shouldn't necessarily be seen as a reason to abandon the system altogether. The existence of paradoxes doesn't automatically invalidate a voting method. Rather, it serves as a reminder that all systems have their quirks and potential for unintended consequences. Understanding these limitations is crucial for informed decision-making and for designing election systems that best serve the needs of voters.