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{{about|voting systems that use ranked ballots|voting systems that use ballots rated on the [[Level of measurement#Interval scale|interval scale]]|cardinal voting systems}}
{{Electoral systems}}

'''Preferential voting''' or '''rank voting''' describes certain [[voting system]]s in which voters rank outcomes in a [[hierarchy]] on the [[Level of measurement#Ordinal scale|ordinal scale]]. When choosing between more than two options, preferential voting systems provide a number of advantages over [[first-past-the-post voting]] (also called plurality voting). This does not mean that preferential voting is always the best system; [[Arrow's impossibility theorem]] proves that no method can simultaneously obtain all properties desirable in a voting system.<ref group=Mankiw name=page475/> There is likewise no consensus among academics or public servants as to the best electoral system.<ref name="eupaper"/>

There are many types of preferential voting, but currently only [[instant-runoff voting]] (alternative vote) and [[single transferable vote]] are used in governmental elections. Instant runoff voting is employed in Australia at the state and federal levels, in Ireland for its presidential elections, and by some cities in the United States, United Kingdom, and New Zealand. The single transferable vote is used for national elections in the Republic of Ireland and Malta, for regional and local elections in Northern Ireland, for all local elections in Scotland, and for some local elections in New Zealand and the United States.

== Variety of systems ==

There are many preferential voting systems, so it is sometimes difficult to distinguish between them.

Selection of the [[Condorcet winner]] is generally considered by [[psephologist]]s as the ideal election outcome,<ref name="nomedian">{{cite book | title=Basic Geometry of Voting | publisher=Springer | author=Saari, Donald | year=1995 | pages=46 | isbn=9783540600640|url=http://books.google.com/books?id=aeJQi0k8mf8C&lpg=PP1&dq=Basic%20Geometry%20of%20Voting&pg=PA46#v=onepage&q&f=false}}</ref> so "Condorcet efficiency" is important when evaluating different methods of preferential voting.<ref name=pp649>Gofman and Feld, 2004, pp. 649</ref> This choice is also the one that would win every two-way contest against every other alternative.<ref group=Mankiw name=page478-479 />

Another criterion used to gauge the effectiveness of a preferential voting system is its ability to withstand manipulative voting strategies,<ref name=pp647>Gofman and Feld, 2004, pp. 647</ref> when voters cast ballots that do not reflect their preferences in the hope of electing their first choice. This can be rated on at least two dimensions—the number of voters needed to game the system<ref name=pp652>Gofman and Feld, 2004, pp. 652</ref> and the complexity of the mechanism necessary.{{citation needed|date=July 2012}}

=== Instant-runoff or preferential voting ===
{{Main|Instant-runoff voting}}
Used in national elections in Australia, this system simulates a series of runoff elections. If no candidate is the first choice of more than half of the voters, then all votes cast for the candidate with the fewest number of first choices are added to the totals of the top-ranked candidate still in the race.<ref name=wsj1/> If this does not result in any candidate receiving a majority, further rounds of redistribution occur.<ref name=wsj1/>

This method is thought to be resistant to manipulative voting as the only strategies that work against it require voters to highly rank choices they actually want to see lose.<ref group=G&F name=pp652/> At the same time, this system fails the [[monotonicity criterion]], where ranking a candidate higher can lessen the chances he or she will be elected. Additionally, alternative voting has a lower Condorcet efficiency than similar systems when there are more than four choices.<ref group=G&F name=pp647/>

=== Borda count ===
{{Main|Borda count}}
In the [[Borda count]], ballots are counted by assigning a point value to each place in each voter's ranking of the candidates, and the choice with the largest number of points overall is elected.<ref group=Mankiw name=page475/> This method is named after its inventor, French mathematician [[Jean-Charles de Borda]].<ref group=Mankiw name=page475/> Instead of selecting a Condorcet winner, this system may select a choice that reflects an average of the preferences of the constituency.{{citation needed|date=July 2012}}

However, as explained in the main article, in some circumstances the Borda count may degenerate into a first-past-the-post ballot.

This system suffers from the fact that the outcome it selects is dependent on the other choices present{{clarify|date=October 2013}}. That is, the Borda count does not exhibit [[independence of irrelevant alternatives]]<ref group=Mankiw name=page475/> or [[independence of clones]]. The Borda count can be easily manipulated by adding candidates, called clones, whose views are identical to the preferred candidate's. An example of this strategy can be seen in [[Kiribati]]'s 1991 Presidential nomination contest.<ref>Reilley, Benjamin. [http://rangevoting.org/ReillySCSS.pdf "Social Choice in the South Seas: Electoral Innovation and the Borda Count in the Pacific Island Countries"]. International Political Science Review (2002), Vol 23, No. 4, 355–372</ref>

=== Single transferable vote ===
{{Main|Single transferable vote}}
This is currently one of the preferential voting systems most used by countries and states.<ref group=notes name=note/> It uses multi-member constituencies. Any candidates that achieve the number of votes required for election (the "quota") are elected and their surplus votes are redistributed to the voter's next choice candidate.<ref group=CEPPS name="stvgloss"/> Once this is done, if not all places have been filled then the candidate with the smallest amount of votes is eliminated, and their votes are also redistributed to the voter's next choice. This whole process is repeated until all seats are filled. This method is also called the Hare-Clark system.<ref group=CEPPS name="stvgloss"/>

{{Reflist|group=notes|refs=<ref name=note>See table in [[#Use by polities|use by polities]] below</ref>}}

== Superiority v. FPTP ==
{{POV|Neutral viewpoint needed for comparison to "FPTP"|date=July 2012}}
When choosing between more than two options, preferential voting achieves outcomes better than those produced by a first-past-the-post system. When endorsing a switch to a preferential voting system in 2011, British politician [[Nick Clegg]] stated, "first-past-the-post leads to a whole host of problems... it means [[Member of Parliament|MP]]s can go about their business without ever having to appeal to a majority of their own constituents...".<ref name=corruption>{{cite video | url=http://www.bbc.co.uk/news/uk-politics-12505971 | title=Votes referendum: Deputy PM Nick Clegg's speech in full | publisher=BBC | date=18 February 2011  | people=Nick Clegg}}</ref> He also stated that a preferential voting method like [[instant runoff voting]] would result in politicians "work[ing] harder to appeal to more people than before".<ref name=corruption/> Academic experts have also rejected first-past-the-post; at a 2011 [[London School of Economics and Political Science|LSE]] workshop attended by 22 voting theory specialists, none endorsed first-past-the-post as the "best voting procedure".<ref>{{cite news | url=http://www2.lse.ac.uk/newsAndMedia/news/archives/2011/04/VotingSystems.aspx | title=Voting experts unanimously reject First Past the Post | work=London School of Economics and Political Science | date=21 April 2011 | accessdate=June 29, 2012}}</ref>

The first-past-the-post system will indeed occasionally elect a candidate who would have lost out to every other option in a two-way contest (the so-called [[Condorcet loser criterion|Condorcet loser]]) by [[vote splitting|splitting the opposition vote]]. It happens even more frequently (for a similar reason) that the winner is not the Condorcet winner.<ref group=Mankiw name=page478-479/>

Many countries use a [[two-round system]] (a runoff election) to improve the fairness of the election.

Many arguments for preferential voting being superior to first-past-the-post rely to some extent on several assumptions: that voters have [[single peaked preferences]] over a single dimension (e.g. liberal v. conservative), that choices can be placed on a [[Continuum (set theory)|continuum]], and that voters know accurately where each candidate lies on that continuum. However even if these assumptions are only partially true, the first-past-the-post system is still likely to be less fair.

==Uniqueness of votes==
If there are a large number of candidates, which is quite common in [[Single transferable vote]] elections, then it is likely that many preference voting patterns will be unique to individual voters.<ref>[http://web.archive.org/web/20041215021221/http://election.polarbears.com/art0037.htm Election database] 1st February 2004</ref><ref>[http://web.archive.org/web/20050523021828/http://www.cev.ie/htm/report/first_report/pdf/05Part.pdf Irish Commission on Electronic Voting] 2004</ref> For example, in the [[Irish general election, 2002]], the electronic votes were published for the [[Dublin North (Dáil Éireann constituency)|Dublin North]] constituency.<ref>[http://web.archive.org/web/20020604232303/http://www.dublincountyreturningofficer.com/Results/Votes_Dublin_North.zip Dublin County Returning Officer] complete table of votes cast Dublin North (zip file)</ref> There were 12 candidates and almost 44,000 votes cast. The most common pattern (for the three candidates from one party in a particular order) was chosen by only 800 voters, and more than 16,000 patterns were chosen by just one voter each.

The number of possible [[total order|complete rankings]] with no ties is the [[factorial]] of the number of candidates, ''N'', but with ties it is equal to the corresponding [[ordered Bell number]] and is [[asymptotic analysis|asymptotic]] to
: <math>\frac{N!}{2(\ln 2)^{N+1}}</math>.<ref>{{cite book | last = Wilf | first = Herbert S. | authorlink = Herbert Wilf | title = generatingfunctionology | origyear = 1990 | url = http://www.math.upenn.edu/~wilf/DownldGF.html | accessdate = 2006-08-06 | edition = Second Edition |date=January 1994 | publisher = [[Academic Press]] | isbn = 0-12-751956-4 | pages = 175–176 | chapter = Chapter 5: Analytic and asymptotic methods }}</ref>

In the case common to [[Instant runoff voting|IRV]] in which no ties are allowed, except for unranked candidates who are tied for last place, the number of possible rankings for ''N'' candidates is precisely
: <math> \sum_{n=1}^{N-1} \frac{N!}{n!} = \lfloor (e-1)N! - 1 \rfloor = \mathrm{floor}\left( (e-1)N! - 1 \right)</math>.<ref>[http://oeis.org/A007526 OEIS A007526]</ref>

== Use by polities ==
{{Refimprove|date=July 2012}}

;Countries:
{| class="wikitable sortable"
|-
!Nation
|Year of first use
|Type
|Notes
|-
|[[Australia]] ||1918<ref>{{cite web | url=http://www.dfat.gov.au/facts/electoral_system.html | title=Our electoral system | publisher=Australian Department of Foreign Affairs and Trade | work=About Australia | date=May 2008 | accessdate=June 28, 2012}}</ref> ||[[single transferable vote]], alternative vote||From 1949, the [[single transferable vote]] method has been used for upper house legislative elections.<ref group=Sawer name=chart/> Alternative vote is used for lower house elections.<ref group=CEPPS name=aus/>
|-
|[[Austria]]||1949<ref name="table45">{{cite book | url=http://books.google.com/books?id=Pr5xafKQzbAC&lpg=PA3&ots=wubQ_hXYYW&dq=Parliamentary%20Democracy%3A%20Promise%20and%20problems&lr&pg=PA131#v=onepage&q&f=false|title=Parliamentary Democracy: Promise and Problems | publisher=Oxford University Press | author=Kaare Ström, Wolfgang C. Müller, Torbjörn Bergman - 2006 | year=2006 | pages=131–133}}</ref>||[[open list]]<ref name="eupaper"/>||
|-
|[[Belgium]]||1945<ref name="table45"/>||[[open list]]<ref name="eupaper"/>||
|-
|[[Brazil]]||x||[[open list]]<ref name="mainw">{{cite journal | url=http://kellogg.nd.edu/publications/workingpapers/WPS/141.pdf | title=Politicians, Parties, and Electoral Systems: Brazil in Comparative Perspective | author=Mainwaring, Scott | journal=Comparative Politics |date=October 1991 | volume=24 | issue=1 | pages=21–43}}</ref>||
|-
|[[Chile]]<ref name="mainw"/>||1958-1973||[[open list]]
|-
|[[Colombia]]<ref group=CEPPS name=colombia/>||x||[[open list]]||Political parties choose between open list and [[closed list]]
|-
|[[Cyprus]]||x||[[open list]]<ref name="eupaper"/>||
|-
|[[Czech Republic]]<ref group=CEPPS name=cz/> ||x||[[contingent vote]]||only used to decide lower house legislative elections
|-
|[[Denmark]]||1945<ref name="table45"/>||[[open list]]<ref name="eupaper"/>||
|-
|[[Estonia]]||x||[[open list]]<ref group=CEPPS name=est/>||As of 2001 [[single transferable vote]] had been in use since 1990 to decide legislative elections.<ref group=Sawer name=chart/> This is no longer the case.<ref group=CEPPS name=est/> Estonia's current open list system may not actually be a preferential voting system as it may be that voters cast only one preference vote.
|-
|[[Fiji]]<ref>{{cite web | url=http://www.servat.unibe.ch/icl/fj00000_.html#S054_ | title=Section 54: Voting and other matters | publisher=International Constitutional Law Project | work=Constitution of Fiji | accessdate=June 29, 2012}}</ref> ||1998||alternative vote||
|-
|[[Finland]]||1945<ref name="table45"/>||[[open list]]<ref name="eupaper"/>||
|-
|[[Greece]]||1975-1984, 1996<ref name="table45"/>||[[open list]]<ref name="eupaper"/>||
|-
|[[Hong Kong]]||1998<ref>The fact that Hong Kong began using preferential voting in 1998 can be seen from two sources:
*Minutes from a 1997 LegCo meeting include a proposal to use "preferential elimination voting" for the three smallest functional constituencies. See, {{cite web | url=http://www.legco.gov.hk/yr97-98/english/bc/bc53/minutes/bc531109.htm | title=Legislative Council Bill (Minutes) 11 Sept 97 | publisher=The Legislative Council Commission | accessdate=July 2, 2012}}
*1998 is the first year "preferential elimination voting" can be found in the Hong Kong yearbook. See, {{cite web | url=http://www.yearbook.gov.hk/1998/ewww/02/0209/middle-middle.htm | title=The Electoral System: b. Functional Constituency | publisher=Government Information Centre of Hong Kong | work=Hong Kong Yearbook 1998 | accessdate=July 2, 2012}}</ref>||alternative vote<ref name=same>{{cite web | url=http://www.eac.gov.hk/pdf/legco/2012lc_guide/en/chapter_3.pdf | title=Ch. 3, FUNCTIONAL CONSTITUENCIES: The Preferential Elimination System of the 4 SFCs | publisher=Hong Kong Electoral Affairs Comisson | work=Guidelines on Election-related Activities in respect of the Legislative Council Election | accessdate=June 29, 2012}}</ref>||alternative vote is only used in the 4 smallest of Hong Kong's 29 [[Functional constituency (Hong Kong)|functional constituencies]].<ref>{{cite web | url=http://www.eac.gov.hk/en_txt/legco/fc.htm | title=Functional Constituency Elections | publisher=Hong Kong Electoral Affairs Commission | work=2000 Legislative Council Elections | year=2000 | accessdate=June 29, 2012}}</ref> Officially called preferential elimination voting, the system is identical to the alternative vote.<ref name=same/>
|-
|[[Indonesia]]||2004<ref>{{cite web | title=Indonesia: Continuity, Deals and Consensus | url=http://aceproject.org/ace-en/topics/es/esy/esy_id/ | publisher=ACE Electoral Knowledge Network | work=Electoral Systems | accessdate=July 6, 2012}}</ref>||[[open list]]||only used to decided the elections of one legislative chamber<ref group=CEPPS name=indo/>
|-
|[[Iraq]]<ref>{{cite web | url=http://www.cfr.org/democracy-and-human-rights/iraqs-political-landscape/p18411 | title=Reshuffling the Political Deck | publisher=Council on Foreign Relations | work=Backgrounder: Iraq's Political Landscape | date=February 5, 2009 | accessdate=July 8, 2012 | author=Bruno, Greg}}</ref>||2009||[[open list]]
|-
|[[Ireland]]<ref group=Sawer name=chart/>||1922||alternative vote, [[single transferable vote]]||Single transferable vote is used to decide legislative elections only.<ref group=Sawer name=chart/> Since 1937 Ireland has used the alternative vote to decide presidential elections.<ref group=Sawer name=chart/>
|-
|[[Italy]]||1946-1994<ref name="table45"/>||[[open list]]<ref>{{cite journal | url=http://mpra.ub.uni-muenchen.de/5626/1/MPRA_paper_5626.pdf |title=Pork-Barrel Politics in Postwar Italy, 1953-94 | authors=Miriam A. Golden, Lucio Picci | journal=American Journal of Political Science |date=April 2008 | volume=52 | issue=2}}</ref>||
|-
|[[Latvia]]<ref group=CEPPS name=lat/>||x||[[open list]]||only used to decide legislative elections
|-
|[[Liechtenstein]]||x||[[open list]]<ref name="eupaper"/>||
|-
|[[Luxembourg]]||1945<ref name="table45"/>||[[open list]]<ref group=CEPPS name=luxembourg/>
|-
|[[Malta]]<ref group=Sawer name=chart/>||1921||[[single transferable vote]]||
|-
|[[Nauru]]||1968<ref group=Sawer name=chart/>||[[Borda count]]<ref group=CEPPS name="bordamod"/>||Nauru uses the Dowdall system, which is an improved version of the Borda count.<ref group=CEPPS name="bordamod"/>
|-
|[[Netherlands]]||1945<ref name="table45"/>||[[open list]]<ref group=CEPPS name=net/>||only used to decide lower house legislative elections<ref group=CEPPS name=net/>
|-
|[[New Zealand]]||x||[[single transferable vote]]<ref name=caveat>{{cite web | url=http://www.stv.govt.nz/stv/index.htm | title=STV - It's Simple To Vote | publisher=New Zealand Department of Internal Affairs | year=2010 | accessdate=June 29, 2012}}</ref>||alternative vote is used in only some elections, such as district health boards as well as some city and district councils.<ref name=caveat/>
|-
|[[Northern Ireland]]||1973<ref group=Sawer name=chart/>||[[single transferable vote]]<ref>{{cite web | url=http://www.eoni.org.uk/index/faqs/pr-stv-voting-system-faqs.htm#01 | title=Frequently Asked Questions - PR/STV Voting System | publisher=Electoral Office for Northern Ireland | year=2006 | accessdate=June 29, 2012}}</ref>||
|-
|[[Norway]]||1945<ref name="table45"/>||[[open list]]<ref group=CEPPS name=norway/>
|-
|[[Papua New Guinea]]||2007<ref>{{cite web | url=http://news.smh.com.au/breaking-news-world/observers-urge-peaceful-png-election-20120620-20nuw.html | title=Observers urge peaceful PNG election | publisher=The Sydney Morning Herald | date=June 20, 2012 | accessdate=June 29, 2012 | author=Blackwell, Eoin}}</ref>||alternative vote<ref group=G&F name=pp653/>||Between 1964 and 1975 PNG used a system that allowed voters the option of ranking candidates.<ref group=Sawer name=chart/> Currently, voters must rank only their top three choices.<ref>{{cite web | url=http://www.pngec.gov.pg/ | title=Voting | publisher=Electoral Commission of Papua New Guinea | year=2011 | accessdate=June 30, 2012}}</ref>
|-
|[[San Marino]]||x||[[open list]]<ref name="eupaper">{{cite web | url=https://ecprd.secure.europarl.europa.eu/ecprd/getfile.do;jsessionid=3b490694614cde33796973863f72c657?id=5063 | title=Electoral Systems in Europe: An Overview | publisher=European Centre for Parliamentary Research and Documentation | location=European Parliament in Brussels|date=October 2000 | accessdate=July 6, 2012}}</ref>||
|-
|[[Slovakia]]<ref group=CEPPS name=slovak/>||x||[[open list]]||only used to decide legislative elections
|-
|[[Slovenia]]||2000<ref>{{cite web | url=http://unpan1.un.org/intradoc/groups/public/documents/UNTC/UNPAN014895.pdf | title=Article 80: The National Assembly; Composition and Election | publisher=United Nations Public Administration Network | work=Constitution of the Republic of Slovenia | pages=47–48|accessdate=July 3, 2012}}</ref>||[[open list]]<ref group=CEPPS name=slovenia/>||Open list is only used to decide lower house legislative elections, and two seats, which are reserved for Hungarian and Italian minorities, are decided using a [[Borda count]].<ref group=CEPPS name=slovenia/>
|-
|[[Sri Lanka]]<ref group=Sawer name=srisawer/>||1978||[[Contingent vote#Variants|contingent vote]] and [[open list]]<ref group=CEPPS name=srilanka/>||In Sri Lanka contingent vote is used to decide presidential elections<ref group=Sawer name=chart/> and legislative elections, [[open list]].<ref group=CEPPS name=srilanka/>
|-
|[[Switzerland]]||x||[[open list]]<ref name="mainw"/>
|-
|[[Zimbabwe]]<ref>{{cite web | url=http://aceproject.org/main/english/es/esb02.htm | title=Negotiations | publisher=ACE Electoral Knowledge Network | work=Administration and Cost of Elections Project | accessdate=July 6, 2012}}</ref>||1979-1985||alternative vote||only used for white candidates
|-
|}

;Federated states:
{| class="wikitable sortable"
|-
!Province/state
|Country
|Years in use
|Type
|Notes
|-
|[[Alberta]]<ref group=Sawer name=chart/>||Canada||1952-1954||[[open list]]||
|-
|[[Australian Capital Territory]]<ref group=Sawer name=chart/>||Australia||1993–present||[[single transferable vote]]||
|-
|[[British Columbia]]<ref group=Sawer name=chart/>||Canada||1926-1955||[[open list]]||
|-
|[[Manitoba]]<ref group=Sawer name=chart/>||Canada||1927-1936||[[open list]]||
|-
|[[New South Wales]]<ref group=Sawer name=chart/>||Australia||1918–present||[[single transferable vote]] (1918-1926), [[contingent vote]] (1926-1928), alternative vote (1929-1980), [[open list]] (1981–present)||Since 1978, NSW has used the single transferable vote method to decide upper house legislative elections only.
|-
|[[Northern Territory]]<ref group=Sawer name=chart/>||Australia||1980 only{{citation needed|date=July 2012}}||x||
|-
|[[Queensland]]<ref group=Sawer name=chart/>||Australia||1892-1942, 1962–present||[[contingent vote]] (1892-1942), alternative vote (1962-1992), [[open list]] (1992–present)||
|-
|[[South Australia]]<ref group=Sawer name=chart/>||Australia||1929-1935, 1982–present||Alternative vote in multi-member districts (1929-1935), [[single transferable vote]] (1982–present)||used to decide upper house legislative elections only
|-
|[[Tasmania]]<ref group=Sawer name=chart/>||Australia||1907–present||[[single transferable vote]]||Since 1909, alternative vote voting has been used in Tasmania to decide upper house legislative elections.
|-
|[[Victoria (Australia)|Victoria]]<ref group=Sawer name=chart/>||Australia||1911–present||[[open list]] (1911-1915), alternative vote (1916–present)||Prior to 1916, Victoria did not use any preferential voting method to decide upper house legislative elections.
|-
||[[Western Australia]]<ref group=Sawer name=chart/>||Australia||1907–present||[[open list]] (1907-1911), alternative vote (1912–present)||Since 1989, Western Australia has used the [[single transferable vote]] method to decide upper house legislative elections
|}

;International organizations:
{| class="wikitable sortable"
|-
!Organization
|Year of first use
|Type
|Notes
|-
|[[European Union]]<ref group=CEPPS name=eu/>||x||option to use [[single transferable vote]]||Member countries can use either [[proportional representation]] (not a type of preferential voting){{citation needed|date=July 2012}} or single transferable vote to elect [[Member of European Parliament|MEP]]s
|}

;Municipalities:
{| class="wikitable sortable"
|-
!City/town
|Years in use
|Type
|Notes
|-
|[[Ann Arbor, MI]]<ref>{{cite web | url=http://www.migreens.org/hvgreens/aa-irv01.htm | title=Instant Runoff Voting (IRV): History of Use in Ann Arbor | publisher=Green Party of Michigan | year=1998 | accessdate=June 29, 2012}}</ref>||1975 only|| alternative vote||
|-
|[[Aspen, CO]]<ref>{{cite news | url=http://www.aspentimes.com/article/20120628/NEWS/120629850/1077&ParentProfile=1058 | title=Marks prevails in lawsuit over Aspen election ballots | work=The Aspen Times | date=June 28, 2012 | accessdate=June 29, 2012 | author=Urquhart, Janet}}</ref>||2009 only||alternative vote||
|-
|[[Berkeley, CA]]<ref name="ala"/>||2010–present||alternative vote||
|-
|[[Burlington, VT]]<ref>{{cite web | url=http://www.vpr.net/news_detail/87372/burlington-voters-repeal-alternative vote-voting/ | title=Burlington Voters Repeal Instant Runoff Voting | publisher=Vermont Public Radio | date=03/03/10 | accessdate=June 29, 2012 | author=McCrea, Lynne}}</ref>||2005-2010||alternative vote||
|-
|[[Hendersonville, NC]]<ref>{{cite web | url=http://www.citizen-times.com/assets/pdf/B090974117.PDF | title=New Voting Method for November 6, 2007: Hendersonville Pilots Instant Runoff Voting | publisher=Henderson County Board of Elections | year=2007 | accessdate=June 29, 2012}}</ref>||2007–present||alternative vote||part of a statewide [[pilot program]]<ref>{{cite news | url=http://www.blueridgenow.com/article/20110408/NEWS/110409860 | title=Hendersonville votes to keep instant runoff ballots | work=BlueRidgeNow.com | date=April 8, 2011 | agency=Times-News | accessdate=June 29, 2012 | author=Harbin, John}}</ref>
|-
|[[London]]||2000<ref>{{cite web | url=http://news.bbc.co.uk/2/hi/in_depth/uk_politics/2000/london_mayor/696396.stm | title=London's elections: How the voting works | publisher=BBC | date=3 May 2000 | accessdate=June 29, 2012}}</ref>-present||[[Contingent vote#Variants|supplementary vote]]<ref name="ukvotingsys">{{cite web | url=http://www.parliament.uk/about/how/elections-and-voting/voting-systems/ | title=Voting systems in the UK | publisher=Parliament of the United Kingdom | accessdate=June 29, 2012}}</ref>||
|-
|[[Memphis, TN]]<ref name=wsj1/>||2011–present||alternative vote||
|-
|[[Minneapolis, MN]]<ref>{{cite web | url=http://minnesota.publicradio.org/display/web/2009/10/30/runoff-voting-qa/ | title=Instant runoff voting FAQ | publisher=Minnesota Public Radio | date=November 2, 2009 | accessdate=June 29, 2012 | author=Gilbert, Curtis}}</ref>||2009–present||alternative vote||
|-
|[[Oakland, CA]]<ref name="ala"/>||2010–present||alternative vote||
|-
|[[Portland, ME]]<ref name=wsj1/>||2011–present||alternative vote||
|-
|[[San Francisco]]||2004<ref>{{cite book |url=http://books.google.com/books?id=_24bJHyBV6sC&lpg=PP1&dq=Gaming%20the%20Vote%3A%20Why%20elections%20Aren't%20Fair&pg=PA170#v=onepage&q&f=fa| title=Gaming the Vote: Why Elections Aren't Fair (And What We Can Do About It) | publisher=Macmillan | author=Poundstone, William | year=2009 | pages=170 | isbn=9780809048922}}</ref>-present|| alternative vote<ref name="wsj1">{{cite news | url=http://online.wsj.com/article/SB10001424052748703864204576321171406816538.html | title=Latest Issue on the Ballot: How to Hold a Vote | work=Wall Street Journal | date=May 14, 2011 | accessdate=June 29, 2012 | author=Bialik, Carl}}</ref>||
|-
|[[San Leandro, CA]]<ref name="ala">{{cite web | url=http://www.acgov.org/rov/rcv/ | title=Ranked-Choice Voting | publisher=Alameda County Registrar of Voters | accessdate=June 29, 2012}}</ref>||2010–present||alternative vote||
|-
|[[St. Paul, MN]]||2011<ref>{{cite web | url=http://minnesota.publicradio.org/collections/special/columns/cities/archive/2011/11/election-day-in-st-paul-tomorrow.shtml | title=Election Day in St. Paul Tuesday | publisher=Minnesota Public Radio | date=November 7, 2011 | accessdate=June 29, 2012 | author=Baran, Madeleine}}</ref>-present ||alternative vote<ref>{{cite web | url=http://www.co.ramsey.mn.us/elections/ranked_voting.htm | title=Ranked Voting Information | publisher=Ramsey County | accessdate=June 29, 2012}}</ref>||
|-
|[[Takoma Park, Maryland|Takoma Park, MD]]<ref>{{cite web | url=http://takomaparkmd.gov/clerk/election/2011/index.html#runoff | title=CITY OF TAKOMA PARK ELECTION 2011 | publisher=City Of Takoma Park | year=2011 | accessdate=June 29, 2012}}</ref>||2006–present ||alternative vote||
|-
|[[Telluride, CO]]<ref name="someclaim">{{cite web | url=http://www.telluride-co.gov/Modules/ShowDocument.aspx?documentid=2923 | title=Instant Runoff Voting Brochure | publisher=Town of Telluride | year=2011 | accessdate=June 29, 2012}}</ref>||2011–present||alternative vote||
|}

==See also==
*[[FairVote]]

==External links==
* Brent, Peter, [http://blogs.theaustralian.news.com.au/mumble/index.php/theaustralian/comments/short_history_of_preferential_voting/ A Short History of Preferential Voting (in Australia)] Mumble Blog, ''The Australian''. 17 April 2011.

==References==
{{reflist|2}}
{{reflist|group=Mankiw|refs=<ref name=page478-479>{{cite book | title=Principles of Microeconomics | publisher=South-Western Cengage Learning | author=[[Gregory Mankiw]] | edition =6| year=2012 | isbn=978-0-538-45304-2|pages=478–479}}</ref><ref name=page475>{{cite book | title=Principles of Microeconomics |pages=475}}</ref>}}
{{reflist|group=Sawer|refs=,<ref name=chart>{{cite book | title=Elections: Full, Free & Fair | publisher=Federation Press | author=Sawer, Marian | year=2001 | pages=93 | isbn=9781862873957|url=http://books.google.com/books?id=btoKe4kwK2gC&lpg=PA104&vq=malta&dq=sri%20lanka%20contingent%20vote&pg=PA93#v=onepage&q&f=false}}</ref><ref name=srisawer>{{cite book | title=Elections: Full, Free & Fair |pages=95|url=http://books.google.com/books?id=btoKe4kwK2gC&lpg=PA95&dq=sri%20lanka%20contingent%20vote&pg=PA95#v=onepage&q&f=false}}</ref>}}
{{reflist|2|group=CEPPS|refs=,<ref name="stvgloss">{{cite web | url=http://www.electionguide.org/glossary.php | title=Glossary | work=ElectionGuide | publisher=Consortium for Elections and Political Process Strengthening | accessdate=July 1, 2012}}</ref><ref name=eu>{{cite web | url=http://www.electionguide.org/country.php?ID=244 | title=Country Profile: European Union | date= 02/04/2010 | accessdate=June 30, 2012}}</ref><ref name=colombia>{{cite web|url=http://www.electionguide.org/country.php?ID=48|title=Country Profile: Colombia|date=2012-06-19|accessdate = 07/08/2012}}</ref><ref name=luxembourg>{{cite web|url=http://www.electionguide.org/country.php?ID=126|title=Country Profile: Luxembourg|date=02/04/2010|accessdate = 07/08/2012}}</ref><ref name=norway>{{cite web|url=http://www.electionguide.org/country.php?ID=162|title=Country Profile: Norway|date=2011-03-18|accessdate = 07/08/2012}}</ref><ref name=srilanka>{{cite web | url=http://www.electionguide.org/country.php?ID=201 | title=Country Profile: Sri Lanka | date=2010-02-18 | accessdate=June 30, 2012}}</ref><ref name=slovenia>{{cite web | url=http://www.electionguide.org/country.php?ID=195 | title=Country Profile: Slovenia | date=2012-02-28 | accessdate=June 30, 2012}}</ref><ref name=net>{{cite web | url=http://www.electionguide.org/country.php?ID=152 | title=Country Profile: Netherlands | date=2010-10-14 | accessdate=June 30, 2012}}</ref><ref name="bordamod">{{cite web | url=http://www.electionguide.org/country.php?ID=150 | title=Country Profile: Nauru | date=2011-11-16 | accessdate=June 30, 2012}}</ref><ref name=indo>{{cite web | url=http://www.electionguide.org/country.php?ID=102 | title=Country Profile: Indonesia | date=2010-11-26 | accessdate=June 30, 2012}}</ref><ref name=slovak>{{cite web | url=http://www.electionguide.org/country.php?ID=194 | title=Country Profile: Slovakia | date=02/01/2012 | accessdate=June 30, 2012}}</ref><ref name=lat>{{cite web | url=http://www.electionguide.org/country.php?ID=119 | title=Country Profile: Latvia| date=08/05/2011 | accessdate=June 30, 2012}}</ref><ref name=est>{{cite web | url=http://www.electionguide.org/country.php?ID=69 | title=Country Profile: Estonia | date=2011-04-15 | accessdate=June 30, 2012}}</ref><ref name=cz>{{cite web | url=http://www.electionguide.org/country.php?ID=58 | title=Country Profile: Czech Republic | date= 2012-04-25 |accessdate=June 30, 2012}}</ref><ref name=aus>{{cite web | url=http://www.electionguide.org/country.php?ID=14| title=Country Profile: Australia | date= 2010-07-26|accessdate=June 30, 2012}}</ref>}}
{{reflist|group=G&F|refs=,<ref name=pp647>Gofman and Feld, 2004, pp. 647</ref><ref name=pp652>Gofman and Feld, 2004, pp. 652</ref><ref name=pp653>{{cite journal | url=http://www.polisci.upenn.edu/ppec/sawyer/Speakers/Speakers'%20Publications/Feld-Alternative%20vote%20Coombs%20rule.pdf | title=If you like the alternative vote (a.k.a. the instant runoﬀ), then you ought to know about the Coombs rule | author=Bernard Grofman, Scott L. Feld | journal=Electoral Studies | year=2004 | volume=23 | pages=653}}</ref>}}

{{voting systems}}

[[Category:Preferential electoral systems|*]]
[[Category:Proportional representation electoral systems]]

Polyhalogen ions - Revision history

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