How Should We, The People, Tally Ranked Ballots?
I’d like to thank Move to Amend for organizing a cathartic People’s Movement Assembly to re-imagine the US constitution. Connecting with a creative, intelligent, and diverse group to ponder what comes next was positively inspiring.
I was heartened to hear such broad support for using ranked ballots during the assembly. Social scientists recognize more than a dozen prominent ways of tallying up those ranked ballots, each with differing fulfillment of fairness criteria. I’d like to ask our movement: what does the term “Ranked Choice Voting” mean to us? Some people explicitly equated the term with Instant Runoff Voting. Others were less specific. For our movement, does “Ranked Choice Voting” prescribe Instant Runoff as the one and only way to tally up the ranked ballots, or do we understand it more broadly — voters rank candidates and election administrators use any of several reasonable methods that social scientists have devised to tally them up?
I like Instant Runoff as a way of tallying ranked ballots, and I think our movement deserves a way that is even more fair. We achieve more representative government when we force the people in power to acknowledge more information from the people over which they rule. Kings and Queens were not forced to acknowledge any information from their subjects. In the US, through a painstaking process of defeating discriminatory practices, people in power have on average been forced to acknowledge more information in the form of an increasing number of simple “pick-one” ballots. More recently, several cities and the state of Maine have offered people ranked ballots as a way of collecting more information from the people in hopes of electing more representative leaders. So far, most are tallying ballots with Instant Runoff.
The qualm I have with Instant Runoff is that it ignores too much information from ranked ballots, and consequently, it cannot guarantee that it will elect the candidate who obviously deserves to win. If you looked at all of the information on every voter’s ranked ballot, you could find a candidate that was more popular when compared to every other individual candidate. Instant Runoff’s first step is to ignore all information on the ranked ballots except for voters’ first choices. If voters’ first choices reveal that no candidate has the majority of the support of the electorate, Instant Runoff then starts to consider some voters’ second choices. Importantly, it only considers the second choice on a small number of ballots — those submitted by voters whose judgement was so out of step with the rest of the electorate that they picked the least popular candidate as their first choice.
Instead of using a tallying process that reluctantly considers as little of the information on voters’ ranked ballots as possible, we can use a tallying process that defaults to considering every voters’ opinion of every candidate. We can use that larger amount of information to put candidates through a much more rigorous competition before we award them the opportunity to represent us.
Normally, this is the part of the movie where a voting nerd busts out formal jargon and alienates most of their audience. To avoid glazing anyone’s eyes over, I think it’s helpful to think about elections via the imperfect analogy of a sports tournament.
Imagine that you got tasked with organizing a tournament. You were given unlimited resources. Say the objective of the tournament was not to declare a winner in the fewest number of games, nor was it to produce the best TV — we have enough of that in politics! Imagine that the purpose was to rigorously select a fair winner. If it were me, I would conduct a round-robin tournament.
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. https://commons.wikimedia.org/wiki/File:Round-robin_tournament_10teams_en.png
In a round-robin tournament, each competitor plays a one-on-one match against every other competitor. If a competitor wins all of their matches against every other competitor, they deserve to win the tournament. If we wanted to be sure, we could run multiple rounds of this tournament. If a competitor won more often than they lost against every single other competitor, they clearly deserve to win the tournament.
It turns out we can subject candidates to this rigorous selection process with ranked ballots if we break each ranked ballot down into pairs of candidates. When a ranked ballot says A > B > C, it’s the same thing as saying A > B, and B > C, and A > C.
Each pair tells us the result of a match. When we tally ranked ballots this way, each ballot contributes a whole round of a round-robin tournament to our understanding of the people’s preferences. The more ballots we tally, the more rounds of a round-robin tournament we run, and the clearer it becomes who deserves to win.
On the small scale, people are using Ranked Pairs find the winner of chili cook-offs. On the medium scale, Madison, Wisconsin’s municipal legislators used it to appoint an interim municipal legislator, and to nominate members to the new Police Civilian Oversight Board. Looking larger, and further north, Canadian MP Ron McKinnon proposed using Ranked Pairs voting to achieve an insightful system of mixed-member proportional representation.
Social science tells us that Instant Runoff fulfills 9 out of 16 common fairness criteria, whereas Ranked Pairs fulfills 13 (details). When natural science shows us better ways to manage our environment, our movement’s members respond. When social science shows us better ways to manage our elections, do we answer its call?
Should we tally ranked ballots using as little information as possible from as few ballots as possible, or should we tally ranked ballots in a way that defaults to considering all voters’ opinions of all candidates?
To be clear, if I were faced with a referendum asking whether to keep our current voting system, or to switch to tallying ranked ballots via Instant Runoff, I would vote for Instant Runoff in a heartbeat. Any kind of ranked voting is going to be better than our current system. But while we’re re-imagining the fundamentals of representative democracy, why not reach for something that is more consistent with our belief in science, uses as much information as possible from each voter, and requires a more rigorous competition in order to win the right to represent “We, the People”?
Are you an activist, lawyer, marketer, or educator? Help us spread this idea! Here’s one way we might brand it.
Are you a software developer or web designer? Help us build free, open-source Ranked Pairs software on GitHub.
Please check out Canadian MP Ron McKinnon’s vision of how to achieve a mixed-member proportionally representative legislature using Ranked Pairs voting.
“Outlaw The Election Spoiler” — Lucas Dailey
Tideman, T.N. Independence of clones as a criterion for voting rules. Soc Choice Welfare 4, 185–206 (1987). https://doi.org/10.1007/BF00433944
Zavist, T.M., Tideman, T.N. Complete independence of clones in the ranked pairs rule. Soc Choice Welfare 6, 167–173 (1989). https://doi.org/10.1007/BF00303170