Ranked voting

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Ranked voting" – news · newspapers · books · scholar · JSTOR (July 2024) (Learn how and when to remove this message)

Ovals

Names

Numbers

Various types of ranked voting ballot

Part of the Politics and Economics series
Electoral systems
Comparison of electoral systems Social choice theory Mechanism design List (By country)
Single-winner methods Single vote-runoff methods Plurality (FPP) Two-round (US: Jungle primary) Partisan primary Alternative vote (US: Ranked-choice) Condorcet-IRV Condorcet methods Ranked pairs Schulze Minimax Kemeny–Young Nanson Condorcet-IRV Maximal lottery Positional voting First-preference plurality Borda count Anti-plurality voting Cardinal / graded methods Score voting Approval voting Majority judgment STAR voting Quadratic voting
Proportional representation Party-list List type Open list Closed list Localized list Spare vote Apportionment Highest averages Largest remainders National remnant Biproportional apportionment Single transferable vote (Quota methods) Hare STV (Gregory · Wright) Schulze STV CPO-STV Single non-transferable vote Single divisible vote Approval-based committee Thiele's method Phragmen's method Expanding approvals rule Method of equal shares Weighted and Fractional social choice Direct representation Interactive representation Liquid democracy Maximal lottery
Mixed systems By type of representation Winner-take-most Mixed-member proportional Non-compensatory mixed systems Parallel voting Majority bonus Compensatory mixed systems Additional member system Mixed single vote Scorporo Double simultaneous vote Mixed ballot transferable vote Alternative Vote Plus Dual-member proportional Rural–urban proportional
Voting system criteria Spoiler-resistance Condorcet criterion Smith independence Spoiler independence Clone independence Strategy-resistance No lesser evil voting IIA Later-no-harm Later-no-help Rational response Participation criterion Monotonicity criterion Reversal symmetry
Social and collective choice Impossibility theorems Arrow's theorem Impossibility of majority-rule Moulin's impossibility theorem Gibbard's theorem Fishburn's theorem Positive results Median voter theorem Condorcet's jury theorem May's theorem Campbell-Kelly theorem Harsanyi's utilitarian theorem Tournament sets Smith set Landau set Copeland set Split-cycle set Bipartisan set
Politics portal Economics portal
v t e

Ranked voting is any voting system that uses voters' orderings (rankings) of candidates to choose a single winner. For example, Dowdall's method assigns 1, 1⁄2, 1⁄3... points to the 1st, 2nd, 3rd... candidates on each ballot, then elects the candidate with the most points. Ranked voting systems vary dramatically in how preferences are tabulated and counted, which gives each one very different properties.

Ranked voting systems are usually contrasted with rated voting methods, which allow voters to indicate how strongly they support different candidates (e.g. on a scale from 0-10).^[1] Rated voting systems use more information than ordinal ballots; as a result, they are not subject to many of the problems with ranked voting (including results like Arrow's theorem).^[2][3][4]

Although not usually described as such, the most common ranked voting system is the well-known plurality rule, where each voter gives a single point to the candidate ranked first and zero points to all others. The most common non-degenerate ranked voting rule is the closely-related alternative vote, a staged variant of the plurality system that repeatedly eliminates last-place plurality winners.^[5]

In the United States and Australia, the terms ranked-choice voting and preferential voting are usually used to refer to the alternative or single transferable vote by way of conflation. However, terms these have also been used to refer to ranked voting systems in general.