Approval Voting “Tactics”

Introduction

Tactical voting is when voters don’t cast purely honest ballots. While voters do this to a limited extent with Approval Voting, the voting system still behaves remarkably well. For instance, voters can always express their honest favorite. And voting for just one candidate only occurs in limited situations. That’s right. The idea that Approval Voting regresses to bullet voting/Plurality Voting is a complete myth. Below is how Approval Voting strategy is likely to play out in a variety of common scenarios.

Polling assumption

Since there’d be Approval Voting, there’d also be approval polling. It would make no sense to do polling framed in Plurality when a different system is used; it would cease to be informative.

Utility assumption for hypotheticals

In these cases, let’s assume you hate Candidate Awful, are okay with Candidate Bland, and love Candidate Classy. Let’s give them honest utility values (we’re rating them on a 0-10 scale):

  • Awful: 0
  • Bland: 6
  • Classy: 10

Approval Voting example #1

If approval polls:

  • Awful: 50%
  • Bland: 50%
  • Classy: 30%

You want to vote for Bland and Classy here. You vote for Bland because you want Bland to beat Awful. Classy doesn’t have a shot, but you vote for her anyway to show your support and give her ideas more legitimacy.

Approval Voting example #2

If approval polls:

  • Awful: 50%
  • Bland: 50%
  • Classy: 50%

You still vote for Bland and Classy. You don’t vote for Classy alone because you have a strong preference for Bland against Awful. By only voting for Bland or Classy, you risk Awful winning against both of them.

Approval Voting example #3

If approval polls:

  • Awful: 30%
  • Bland: 50%
  • Classy: 50%

You actually only vote for Classy here. When Awful is enough out of the race, you can narrow your sights against Bland and show your support for Classy.

When exactly do you only vote for Classy? It depends on how far out of the competition Bland is. And it depends on how much you dislike Bland along with how likable Bland is compared to Awful. If Awful and Bland are similarly unlikable (you’re indifferent to which one wins), a voter may be more inclined to vote for Classy alone when she is closer to winning.

Approval Voting example #4

If approval polls:

  • Awful: 50%
  • Bland: 30%
  • Classy: 50%

Again, your only vote is for Classy here. It’s not Bland that’s giving competition to Awful anymore; it’s Classy competing against Awful. Whether you include Bland in the vote would depend on how much you actually supported Bland’s views. Like in the first example where Classy had 30% and was a token vote, support for Bland in this case is also a token vote because it likely won’t change the outcome. So, if you wanted to give support for Bland because of some view he had that you liked, then you could get away with supporting him and Classy.

Summary of approach

Step 1: Who is likely to win? Consider the relative utility of each. Of those candidates, approve all whom you prefer. You may end up voting for more than one candidate within this group.

Step 2: Who is unlikely to win? Of those candidates, approve of all you wish to give support.

Conclusion

These examples remove the argument that Approval Voting regresses to Plurality Voting (via bullet voting). There are numerous scenarios (as shown above) when bullet voting simply makes no strategic sense. But notice that when you do only vote for one candidate, it’s done in a way that’s not damaging to the outcome. Also, factoring in who is likely to win is something we do anyway when considering what to do under Plurality Voting. But with Approval Voting, we just have more options on what we can do with that information. Also note that it was always to your advantage to vote your favorite. That will ALWAYS be true with Approval Voting.

Also, when there are more candidates, there are more variations on what to do. Though the concepts are the same. Expectantly, with more candidates, voters will also approve of more candidates on average.  There may also be cross-support from multiple independents/third parties that share certain views.

Finally, even with “tactical” voting, Approval Voting will nearly always choose the candidate that can beat everyone in a head-to-head race. This is called a Condorcet winner. Approval voting does not achieve this flawlessly, but it does an excellent job nonetheless. It is also argued that when Approval Voting doesn’t select the Condorcet winner, it does so for good reason. More on this topic here.

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