Tactical Voting

IRV Degrades to Plurality


A commonly held misconception is that Instant Runoff Voting (IRV) allows voters to support their sincere favorite candidates, without the fear of “throwing away their vote” on “spoilers”. This article demonstrates why this is incorrect. At best, IRV mitigates the spoiler effect, which plurality voting is extremely vulnerable to.

There may, however, be some improvement over plurality with IRV to the degree that voters are not tactical. But this improvement is small compared to approval voting.

Score Voting Threshold Strategy


This article looks at a more technical way to determine how to assign scores in score voting by voting tactically. This approach can be extrapolated to approval voting as well.

Bullet Voting


Bullet voting is the practice of choosing just one candidate despite the ability to choose or rank more. The practice of bullet voting leads to the same outcome as plurality voting since plurality voting restricts voters to choosing one candidate.
A common criticism of score voting and/or approval voting is that they will degrade into sincere plurality voting through bullet voting. It's suggested that this happens because voters won’t want to hurt their favorite candidates by voting for anyone else.

Approval Voting Tactics



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 choosing just one candidate (bullet voting) only occurs in limited situations.

Below is how approval voting strategy is likely to play out in a variety of common scenarios.

Tactical Voting Basics


Tactical voting, also called strategic voting, is when voters cast an insincere ballot in order to increase their expected value for an election outcome. A common example of this behavior is when supporters of a minor party candidate vote for their favorite major party candidate, based on the impression that the minor party candidate is unlikely to win.

Follow The Center for Election Science on: