Instant Runoff Voting (IRV) vs. Approval Voting (AV)

Written by Andrea Bloom on February 26, 2014

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If you're reading this, you may already know a little bit about why alternative voting methods merit exploration and discussion. How most elections are run now, it's reasonable that the candidate preferred by most voters may not win the race. For example, if the top choice of voters is basically evenly split between three candidates and one candidate just a couple points above the others, that candidate will win. But imagine that there is overwhelming support for a different candidate when you look at voters' second choices. And yet, the candidate preferred by most voters does not win.

Before I get into the pros and cons of these two (of many) alternative voting methods, it's important to make clear that in our perspective one doesn't beat the other. Depending on the needs of a community or the types of races, both of these may be an improvement on the status quo.

Instant Runoff Voting (IRV):

Voters indicate, not only a first choice, but also, additional ranked choices for the position at stake. If there are four candidates, each voter specifies a first choice, second choice, etc. The winner is determined as follows. A candidate receiving a majority of first-place votes is an immediate winner. If nobody receives such a majority, then the candidate with the fewest first-place votes is eliminated. On the ballots where this candidate was top ranked, the ranks of all the other candidates are upgraded one step. The first-place votes for the remaining candidates are counted again, with the new first-place votes included. This process is repeated until a candidate receives a majority of first-place votes. IRV duplicates a series of traditional runoffs, but without the need for additional elections.

Example: Ireland's 1990 presidential race provides an example of how IRV works. In the first round, Brian Lenihan won 44% of first choices, Mary Robinson won 38%, and Austin Currie won 17%. After Currie's elimination, Robinson had clear majority support. She won 53% to 47% in the second round of counting.

In 2008, Colorado Common Cause supported HB08-1378, which allows local governments to conduct elections using ranked choice voting.

Approval Voting (AV):

AV is a type of voting that allows a voter to cast a vote for as many of the candidates per office as the voter chooses. The winner of each office is the candidate who receives the most votes.

Both voting systems have advantages over the conventional plurality voting system. Both systems can prevent the "Spoiler" effect (note that proponents of either system over the other can give fairly complicated mathematical scenarios where each system fails to prevent the spoiler effect); both systems should increase voter participation, reduce negative campaigning, and allow alternate candidates to get a more accurate measure of support.


A few other considerations regarding Instant Runoff Voting and Approval Voting:

Majority Rule:

IRV: If no candidate gets a majority of first preferences, candidates at the bottom are sequentially dropped. Each ballot cast for those eliminated candidates is added to the totals of the next choice indicated on that ballot until a candidate achieves a majority. Majority rule is preserved without the need for run-off elections.

AV: Allows for the candidate with the most votes to win. This could cause the defeat of a candidate who was the favorite candidate of the majority of voters. For example, assume 100 voters and two candidates liked by all voters. 99 voters choose to approve of both candidates even though slightly preferring the first candidate to the second. The 100th voter is a tactical voter and chooses to support only the second candidate. As a result, the second candidate wins by one vote, even though 99% of voters prefer the first candidate.


Weighted Voting:

IRV allows voters to express their preferences among the candidates. By making a candidate your second or third choice, there is no harm to the candidate that you ranked as your first choice.

AV requires voters to cast equally weighted votes for candidates they approve of. Voters cannot indicate a strong preference for one candidate and a weak preference for another. As a result, voting for more than one candidate can have the effect of detracting from the ability of your first choice candidate to win - because your second and third choices are given equal weight in the counting room.

Where Implemented:

IRV has been implemented for many governmental elections in the US. See for a full list.

AV has not been implemented in any US governmental election.

More from partners who prefer Approval Voting: The Center for Election Science

More from partners who prefer Instant Run-off Voting: Fair Vote

There is an approval voting bill in the Colorado General Assembly right now. It would allow approval voting in nonpartisan local elections. Bills related to IRV and AV have been introduced and considered in other states, including New York, Massachusetts, Florida, California and elsewhere.


Office: Common Cause National, Common Cause Massachusetts

Issues: Voting and Elections, Voting and Elections

Tags: Registration and Voting Systems, Election Modernization

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