Totally different Voting Strategies Produce Totally different—and Extra Correct—Outcomes

There’s a important ongoing debate in the USA on the deserves of plurality voting (how most American elections are carried out) and the way options could produce extra consultant outcomes. In new analysis, teachers from The Middle for Election Science, the Paris College of Economics, and the College of Strasbourg use the 2016 U.S. presidential election as a case research to debate a number of different voting strategies, their advantages, and their drawbacks.

In 2016, the USA noticed a heated and extremely polarized presidential election with candidates that deeply divided the nation. Amidst the persevering with debates and controversies surrounding the election, one essential query arises: May the end result have been completely different if the U.S. had used another voting system?

In our latest research, we in contrast 4 different voting strategies—plurality, approval, ranked-choice, and vary voting—in opposition to an sincere evaluation measure that requested survey individuals about their want to see every candidate elected inside the context of the 2016 U.S. presidential election. Our findings provide a recent perspective on the affect of voting techniques.

The Examine: A Complete Evaluation of Various Voting Strategies

To realize a deeper understanding of the affect of voting techniques on election outcomes and to uncover the citizens’s true preferences, we carried out an in depth research specializing in the 2016 U.S. presidential election. By analyzing the consequences of various voting strategies, we aimed to find out if the selection of a voting system might result in completely different outcomes and representations of the candidates.

Our research concerned a consultant pattern of greater than 2,000 respondents who participated in a ballot designed to evaluate their preferences utilizing 4 different voting strategies. This ballot happened instantly earlier than the 2016 election. Every of those strategies is exclusive in its personal manner. Right here’s how they work:

Plurality voting (the strategy most American elections use) lets voters choose only one candidate. The candidate with probably the most votes wins.

Approval voting lets voters choose all of the candidates they need—one, two, or nevertheless many—and no rating is important. Once more, the candidate with probably the most votes wins.

Ranked-choice voting (also referred to as immediate runoff voting or RCV) requires voters to rank candidates so as of desire, with the candidate having the fewest first-choice votes being eradicated in every spherical till a candidate has greater than half the remaining first-choice votes. Many in-use poll designs (notably on the time of this research) restrict the rankings to 3, and so this research restricted the rankings to 3 as nicely.

Vary voting (additionally known as rating voting) permits voters to assign a rating to every candidate, with the highest-scoring candidate profitable the election. Our scale used a 0-5, inclusive, vary.

Along with the choice voting strategies, we additionally requested respondents to offer an sincere evaluation of every candidate (additionally utilizing a 0-5, inclusive, scale), indicating the respondent’s sincere want to have that candidate elected. We used this measure of voters’ opinions earlier than the 2016 U.S. presidential election to evaluate the accuracy of every voting technique in capturing voter preferences. To be clear, the sincere evaluation was not asking how respondents would have voted like the opposite questions. Particularly, it requested, “No matter their likelihood of being elected, how a lot do you truthfully need the next to be elected?”

To discover the affect of the variety of candidates on election outcomes, our research additionally included two units of candidates: a brief listing and an extended listing. The shortlist consisted of the 4 candidates who really ran within the 2016 election (Donald Trump, Hillary Clinton, Gary Johnson, and Jill Stein). The lengthy listing featured 5 extra potential candidates who might need participated within the race below completely different circumstances, have been knocked out within the primaries, or have been on solely choose state ballots (Bernie Sanders, Ted Cruz, Michael Bloomberg, Evan McMullin, and Darrell Fort).

Our evaluation concerned analyzing the distribution of votes below every technique, figuring out patterns in voter conduct (akin to tactical voting or the propensity to rank candidates they didn’t like), and exploring the affect of the variety of candidates on election outcomes. By evaluating the outcomes of the choice voting strategies to the sincere evaluation measure, we have been in a position to decide which technique finest represented the true preferences of the citizens and the way the selection of voting technique might doubtlessly change the end result of the election.

Primary Findings: How Voting Strategies Can Form Election Outcomes and Mirror Voter Preferences

Our research revealed a number of key findings concerning the affect of plurality voting and different voting strategies on election outcomes and their accuracy in capturing voter preferences. The next are probably the most important findings:

1. Totally different Voting Strategies Can Decide Totally different Winners

The evaluation of our ballot knowledge indicated that the selection of voting technique can certainly result in completely different election outcomes. Approval and rating voting each recognized Bernie Sanders because the winner (although approval voting confirmed a tie between Sanders and Clinton), whereas ranked-choice voting (RCV) and plurality voting positioned Hillary Clinton because the winner. This discrepancy may be attributed to a number of components which have already been recognized within the literature however seem clearly in our research:

  • Plurality voting and RCV are each prone to vote splitting, by which comparable voters vote for comparable candidates, thus decreasing these candidates’ possibilities to win and as an alternative rising the electoral possibilities of a dissimilar (and doubtlessly much less most well-liked) candidate. Vote splitting is a well known defect of American elections that use plurality voting. RCV can be prone to vote splitting of first-choice votes, which might result in candidates being artificially eradicated early within the course of, a phenomenon frequent in nations utilizing plurality voting with a runoff.
  • Polarizing candidates could obtain extra of the scattered first-choice votes inside a crowded subject below plurality voting and RCV, skewing the outcomes. In distinction, strategies akin to approval and rating voting could profit extra consensus candidates.
  • When translating sincere assessments into rankings, the Condorcet winner (the candidate who would win a head-to-head contest in opposition to each different candidate) could differ from the winner decided by plurality voting and RCV.

Apparently, our findings additionally confirmed that third-party candidates Jill Stein and Gary Johnson carried out considerably higher in approval voting than in RCV or plurality voting, suggesting that different voting strategies can present a extra correct illustration of assist for minor occasion candidates. Within the short-list of candidates, Stein obtained over 10% approval and Johnson obtained roughly 20% approval. See Desk 1 for extra particulars.

Desk 1: Candidate scores below three voting guidelines

Plurality Plurality Approval Approval Vary Vary
Quick Set Lengthy Set Quick Set Lengthy Set Quick Set Lengthy Set
Clinton 47.73 31.38 50.12 39.78 2.33 2.32
Trump 40.52 27.78 42.01 33.73 1.89 2.00
Sanders 19.98 39.25 2.72
Cruz 9.73 21.46 1.93
Johnson 8.25 4.54 20.65 12.16 1.59 1.5
Bloomberg 4.41 11.65 1.67
McMullin 1.73 7.6 1.36
Stein 3.51 .26 11.52 5.06 1.3 1.21
Fort .19 2.18 .95
Desk 1 gives the noticed scores of the candidates for plurality and approval voting as percentages of the inhabitants and for vary voting as common grades (0-5).

We’ve additionally standardized the measure of assist by voting technique in order that they’re extra simply comparable, as you’ll be able to see in Determine 1.

Determine 1: Normalized relative scores (with sincere evaluation)

2. Voting Strategies Fluctuate in Accuracy of Capturing Candidates’ Assist

These completely different voting strategies additionally diverse of their potential to precisely seize voter preferences in comparison with the sincere evaluation management measure. Approval voting and rating voting each carried out nicely right here. It might be of little shock that rating voting did an excellent job, because it makes use of the identical 0-5 scale measure because the sincere evaluation. Approval voting’s efficiency may be equally attributed to its standing as a cardinal voting technique, which asks voters to assign candidates unbiased scores fairly than rank them. Nevertheless, approval voting’s scoring scale is straightforward (zero/one) when in comparison with that of rating voting (which makes use of three or extra ranges). RCV and plurality voting, alternatively, have been much less profitable in capturing the true preferences of the citizens (see Determine 1). 

For instance, our knowledge revealed that some conservative voters in our pattern really favored Sanders, which was extra evident below approval and rating voting than RCV or plurality voting. This demonstrates the potential for different voting strategies to uncover hidden voter preferences and supply a extra correct image of the citizens’s true selections. See Determine 1 for the normalized sincere evaluation scores for every candidate.


Total, our research highlights the significance of contemplating different voting strategies alongside conventional plurality voting to make sure election outcomes that extra intently align with the true preferences of the citizens. By exploring the affect of assorted voting techniques on election outcomes and voter conduct, we hope to contribute to the continued dialogue round broader electoral reform, the potential advantages of adopting different voting strategies within the U.S., and the query of which different technique to decide on. Choosing a correct voting technique for high-stakes elections is essential. The very basis of our democracy will depend on getting this reform proper.

Articles signify the opinions of their writers, not essentially these of the College of Chicago, the Sales space College of Enterprise, or its school.

Originally posted 2023-04-21 10:00:00.