Instant-runoff voting: Difference between revisions

When the [[single transferable vote]] [[voting system]] is applied to a single-winner election it is sometimes called '''instant-runoff voting''' (IRV), as it is much like holding a series of runoff elections in which the lowest polling candidate is eliminated in each round until someone receives [[simple majority |majority]] vote. IRV is often considered independently of multi-winner [[Single transferable vote]] (STV) because it is simpler and because it is the most widely advocated electoral reform in the [[United States|USA]].

Instant-runoff voting is also known as Ranked Choice Voting (RCV), a term useful for describing the voter's experience as well as the appearance of the ballot.

Outside the USA, IRV is known as the '''[[Alternative Vote]]''', '''[[preferential voting]]''', '''single-winner STV''', or the '''[[Thomas Hare|Hare]] System''', though there is room for confusion with some of these terms since they can also refer to STV in general.

IRV is used to elect the [[Australian House of Representatives]], the lower houses of most of [[Australia|Australia's]] [[States of Australia|state]] parliaments, the [[President of Ireland]], the [[Papua New Guinea]] National Parliament, the [[Fiji|Fijian]] [[House of Representatives (Fiji)|House of Representatives]], and the [[Parliament of Nauru|Parliament]] of [[Nauru]]. See below for a more detailed list.

The single-winner variant of STV is used in Australia for elections to the Federal [[Australian House of Representatives|House of Representatives]], for the Legislative Assemblies ("lower houses") of all states and territories except [[Tasmania]] and the [[Australian Capital Territory]], which use regional multi-member constituencies. It is also used for the Legislative Councils ("upper houses") of [[Tasmania]] and [[Victoria (Australia)|Victoria]], although the latter will switch to the multi-member variant from [[2006]]. The multi-member variant of STV is used to elect the [[Australian Senate]] and the Legislative Councils of [[New South Wales]] and [[South Australia]] in statewide constituencies, and of [[Western Australia]] in regional constituencies.

[[Ireland]] uses STV to elect its own parliament and its delegation to the [[European Parliament]] (by the multi-member variant), and its [[President of Ireland|President]] (by the single-member variant). [[Northern Ireland]] also uses the multi-member variant for elections to its [[Northern Ireland Assembly|Assembly]] and for its [[European Parliament|European Parliamentary MPs]]. [[Malta]] uses the multi-member variant for its parliamentary elections.

In the [[Pacific]], the multi-member variant of STV is used to elect the parliament of [[Nauru]], while the single-member variant is used for the [[Fiji|Fijian]] [[House of Representatives (Fiji)|House of Representatives]]. [[Papua New Guinea]] has also decided to adopt it for future elections, starting in [[2007]]. The Fijian system has been modified to allow for both "default preferences", specified by the political party or candidate, and "custom preferences", specified by the voter. Each political party or candidate ranks all other candidates according to its own preference; voters who are happy with that need only to vote for their own preferred candidate, whose preferences will automatically be transferred according to the ranking specified by the candidate. Voters who disagree with the ranking, however, may opt to rank the candidates according to their own preferences. In the [[Fiji election of 2001|last election]], about a third of all voters did so. The ballot paper is divided by a thick black line, with boxes above (for the default options) and below (for customized preferences).

The countries mentioned above all use STV for some or all of their municipal elections. Starting in [[2004]], some municipal areas in [[New Zealand]] also adopted STV to elect mayors (by the single-member variant) and councilors (by the multimember variant). Political parties, cooperatives and other private groups also use STV and/or IRV.

The single winner version of IRV is also used to select the winning bid of both the Summer and Winter Olympics in the [[International Olympic Committee]].

Suggested by [[Robert's Rules of Order]], instant-runoff voting is increasingly used in the United States for non-governmental elections, including student elections at many major universities.

Notable supporters include Republican U.S. Senator [[John McCain]] and [[U.S. Democratic Party presidential nomination, 2004|2004 Democratic presidential primary]] election candidates [[Howard Dean]] and [[Dennis Kucinich]]. The system is favored by many third parties, most notably the [[United States Green Party|Green Party]] and the [[United States Libertarian Party|Libertarian Party]], as a solution to the [[spoiler effect|"spoiler" effect]] third-party sympathizers suffer from under plurality voting (i.e., voters are forced to vote tactically to defeat the candidate they most dislike, rather than for their own preferred candidate). In order to increase awareness of the voting method and to demonstrate it in a real-world situation, the [[Independence Party of Minnesota]] tested IRV by using it in a [[straw poll]] during the 2004 [[Minnesota]] [[caucus]]es (results favored [[John Edwards]]).

==Other ranked ballot methods==

Like IRV, [[Condorcet method]]s and [[Borda count]] methods grant voters the expressive power to rank candidates in order of preference (some such methods also allow voters to rank some candidates equally), but they differ in how the votes are counted and how the winner is determined.

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