rankedvoting

Ranked voting, also known as ranked-choice voting, is an electoral method in which voters rank candidates by preference rather than voting for a single candidate. It can be used in both single-winner elections and, in some forms, multi-winner elections. The goal is to better reflect voter preferences and reduce the effects of vote splitting.

In the common single-winner form, instant-runoff voting (IRV), ballots are tallied by the first choice; if no candidate has a majority, the lowest-ranked candidate is eliminated and their ballots are transferred to the next preference. The process repeats until a candidate receives a majority. In multi-winner elections, the single transferable vote (STV) uses quotas and transfers to fill several seats; candidates meeting a quota are elected and surplus votes are transferred to next preferences.

Other rating-based methods exist in ranking systems, such as the Borda count, which assigns points based on ranking rather than transferring ballots. These systems differ in their properties, how they handle ties, and their susceptibility to strategic voting.

Advantages of ranked voting include promoting majority support, reducing spoiler effects, and allowing voters to express preferences without wasting a vote. It can yield outcomes that better reflect voter preferences in some contexts and may encourage more civil campaigns.

Criticisms include greater ballot complexity, the potential for ballot exhaustion if preferences are not fully listed, and higher administrative costs. In multi-w winner contexts, it may not provide proportional representation and can be sensitive to the specific counting rules used.

Adoption varies by country and jurisdiction, with notable use in Australia and Ireland, and growing use in various U.S. states and cities for select elections.