Approval Voting

What is Approval Voting?

Approval voting (AV) is an alternative method of voting. Unlike plurality voting (PV) -- the most common method in practice today -- where voters pick the single candidate they feel is the most qualified for the position, approval voting allows voters to choose all candidates they feel are qualified.

What would an AV ballot look like?

An AV ballot might look almost exactly like a PV ballot. Here is a quick side-by-side comparison of the two:

Plurality Vote

What is your favorite color?

Red
Orange
Yellow
Green
Blue
Violet
Black
White

Approval Vote

Which colors do you like?

Red
Orange
Yellow
Green
Blue
Violet
Black
White

What are the advantages of AV over PV?

Approval voting provides a better measure of popular opinion. Because AV allows voters more room to express their opinion, the election results provide a much clearer picture of voter preference among candidates, especially when third parties are involved.

Approval voting allows voters to vote honestly. Because everyone can vote for as many candidates as they wish, voting for candidates unlikely to win is no longer "throwing away your vote." Also, approval voting, by its nature, makes it difficult to vote against a candidate, reducing the effectiveness of negative campaigning.

What are the advantages of AV over other methods?

Approval voting is intuitive and practical. Unlike some other alternative voting methods (the Borda Count and Condorcet Voting, for example), AV is straightforward and easy to explain. In fact, if a voter was oblivious to a switch from PV to AV, he would still be able to cast a meaningful vote. While other methods may provide more fine-tuned options for voters, they generally place a much greater responsibility on both voters and voting administrators. Communities would either have to install potentially expensive or quirky electronic voting systems, or face a considerable risk of confused voters casting invalid ballots. After all that work, the end results of the added fine-tuning are relatively small, often not noticeable at all.

In short, the jump from Plurality Voting to Approval Voting would be a small effort with a big improvement; the jump from Approval Voting to a more complex method would be a big effort with a small improvement.

(And yes, this point is up for debate, and this is only my opinion. To read others' takes on the issue, see the links section at the bottom).

Example Scenarios

The following are all possible scenarios designed to illustrate the differences between approval and plurality voting. All of these elections take place in an imaginary nation of 360 voting citizens, where the two major polital parties are the Red and Blue parties.

Case 1: Simple Two-Candidate Election

This is the most basic election scenerio, and the easiest to sort out. There are only two candidates, and everybody has a definite preference to one or the other.

Voter Breakdown Results
No. of
Voters
Plurality
Vote
Approval Vote
Blue Red
216 Blue X  
144 Red   X
PV AV
Blue 216 216
Red 144 144

In this situation, the two voting methods give the exact same results. This is because this election is so clear-cut that there is really no room for interpretation; under circumstances like these, there are no logical arguments that would have Red win this election.

Case 2: Outspoken Third Party

Here, we have the same two major parties, but also a third party -- the Yellow party -- which has a significant amount of support from members of both parties, but not enough to have any real chance of winning the election.

Voter Breakdown Results
No. of
Voters
Plurality
Vote
Approval Vote
Blue Red Yellow
198 Blue X    
18 Blue X   X
18 Red   X X
126 Red   X  
PV AV
Blue 216 216
Red 144 144
Yellow 0 36

This illustrates what is perhaps the greatest strength of approval voting: not a change in the outcome of an election, but a much greater gauge of public opinion. As any third-party supporter will tell you, your vote is not only a means of electing someone to office, but also a political statement. In our election, the Yellow party didn't even make a peep in the Plurality vote, but won 10% of the approval vote, making it known that, though small, they are a force to be reckoned with.

So far, we have only shown examples where the two voting systems have the same winner. Now, we'll look at some situations where approval voting can actually change the outcome of an election.

Case 3: Split Party

Consider what would happen if the Red party split in two -- the Pink and Maroon parties. Between the two of them, they can't decide on a single candidate to support, but all Pink and Maroon supporters agree that either candidate would be better than Blue.

Voter Breakdown Results
No. of
Voters
Plurality
Vote
Approval Vote
Blue Pink Maroon
144 Blue X    
18 Pink   X  
90 Pink   X X
54 Maroon   X X
54 Maroon     X
PV AV
Blue 144 144
Pink 108 162
Maroon 108 198

Under a plurality vote, Blue would win this election despite the fact that 60% of voters feel he is unqualified for the position -- all because the plurality vote forces voters to choose a single candidate, even if you like more than one. Approval voting corrects this, and awards the election to a more mutually likeable candidate.

Case 4: Third Party Detractor

The Red party is united once again, and the Yellow party has made a presence again. This time, the Yellow party is considerably stronger -- but still not strong enough to win the race. However, most of their supporters were drawn away from the Blue party; people who still agree with the Blue candidate, and would probably vote Blue had the Yellow party not come along.

Voter Breakdown Results
No. of
Voters
Plurality
Vote
Approval Vote
Blue Red Yellow
150 Red   X  
120 Blue X    
60 Yellow X   X
30 Yellow     X
PV AV
Blue 120 180
Red 150 150
Yellow 90 90

Here, the approval vote allows the Blue and Yellow parties to co-exist peacefully -- the same election, under the plurality vote, would surely see Blue party members blaming the Yellow party for costing them the election, and many Yellow supporters would switch to their second-choice Blue in fear of a Red victory. Approval voting lets voters choose honestly.

Case 5: Strong Compromising Third Party

This time, the Yellow party is a powerful force, with a real chance of taking the election. The Yellow platform appeals to members of both the Red and Blue parties, although most registered Red and Blue voters have a slight preference to their own parties' candidates.

Voter Breakdown Results
No. of
Voters
Plurality
Vote
Approval Vote
Blue Red Yellow
60 Blue X    
120 Blue X   X
30 Yellow     X
60 Red   X X
90 Red   X  
PV AV
Blue 180 180
Red 150 150
Yellow 30 210

This election shows a couple different things: first, that third parties have more of a fighting chance under approval voting, and second, that approval voting tends to favor moderate candidates and candidates who make an effort to broaden their appeal.

Case 6: Crossing Party Lines

This final election is a bizarre situation, since a glance at the polls provides no obvious winner. What we have is another two-party election where, although more voters would pick Blue as their first choice, Red has crossed the party lines and won significant support among the Blues.

Voter Breakdown Results
No. of
Voters
Plurality
Vote
Approval Vote
Blue Red
108 Blue X  
108 Blue X X
144 Red   X
PV AV
Blue 216 216
Red 144 252

The results of this election, though a bit unusual, bring out the key differences between plurality and approval voting. If we take the results of the plurality vote, 60% of the citizens are happy -- but only 60% of the citizens are content. With the approval vote, we can make 70% of the citizens content -- at the cost of only 40% of them being happy. So, which method gives the better results in this case? It's hard to say. It depends on your own ideas of what a vote should accomplish, and what your idea of fairness is.

More Information

Neal McBurnett has put up a nice and thorough page on approval voting. It has links and articles which discuss approval voting in more depth and explore the mathematics behind approval voting, as well as information on other alternative voting methods.

The November 2000 issue of Discover Magazine printed a good article, "May the Best Man Lose," by Dana Mackenzie, which discusses the approval vote and Borda count (and also inspired me to make this page).

Electionmethods.org, a site detailing a handful of voting methods (including Approval Voting and Condorcet Voting), and political action regarding voting systems.

ApprovalVoting.org, another site of approval voting advocacy and awareness.

Peter A. Taylor has put up a page on Instant Runoff Voting for you, if you'd like to see some other alternatives.


Page maintained by and copyright Catherine Kimport.

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