Editing Vote pairing (section)

== Comparison with other voting systems ==
Vote pairing is most often used as a strategy in [[First-past-the-post voting|first-past-the-post]] voting with [[Plurality voting|winner-takes-all]] constituencies, as they provide the strongest incentives for dishonesty. However, such a strategy can be effective when using [[Ranked voting|ranked-choice voting]] as well. [[Instant-runoff voting|Instant-runoff]] systems are particularly vulnerable to the practice because they frequently fail the [[Favorite betrayal|favorite betrayal criterion]], which means casting a first-rank vote for a third-party can cause a "greater evil" candidate to win.

For example, in the [[2009 Burlington mayoral election]], voters who supported moderate Republican [[Kurt Wright]] eliminated Democrat Andy Montroll in the second round, allowing socialist candidate [[Bob Kiss]] to win. If a similar [[Instant-runoff voting|instant-runoff system]] were adopted nationwide, Republicans in Vermont would have a strong incentive to swap votes with Democrats in districts where the Democrat was unlikely to win. A similar situation occurred in the [[2022 Alaska's at-large congressional district special election|2022 Alaska special election]].

Most [[rated voting]] systems (including [[approval voting]] and [[score voting]]) satisfy the favorite betrayal criterion, rendering vote-pairing fully unnecessary. [[Proportional representation]] systems also make the practice less important (although it can still occur if there are regionally-calculated [[Electoral threshold|electoral thresholds]]).