Historically, the single transferable vote (STV) electoral system has seen a series of relatively modest periods of usage and disusage at various locations around the world. Today it is increasingly popular as a goal of electoral reform, and many jurisdictions are proposing implementation of it as a method of proportional representation. STV has been used in many different local, regional and national electoral systems, as well as to elect various other types of bodies, around the world.

Early history The concept of transferable voting was proposed by Thomas Wright Hill in 1819.

In 1855 in Denmark, Carl Andræ proposed a multi-winner transferable vote system for elections in Denmark. Andræ's system was used in 1856 to elect the Danish Rigsdag, and by 1866 it was also adapted for indirect elections to the second chamber, the Landsting, until 1915.

The English barrister Thomas Hare is generally credited with the conception of Single Transferable Voting as we know it today, and he publicized the idea in his 1857 book Machinery of Representation. Hare's view was that STV should be a means of "making the exercise of the suffrage a step in the elevation of the individual character, whether it be found in the majority or the minority." In Hare's original STV system, he proposed that electors should have the opportunity of discovering which candidate their vote had ultimately counted for, to improve their personal connection with voting.

The noted political essayist, John Stuart Mill, was a friend of Hare and an early proponent of STV. He praised Hare's STV in his 1861 essay Considerations on Representative Government. His contemporary, Walter Bagehot, also praised the Hare system for allowing everyone to elect an MP, even ideological minorities, but added that the Hare system would create more problems than it solved: "[the Hare system] is inconsistent with the extrinsic independence as well as the inherent moderation of a Parliament – two of the conditions we have seen, are essential to the bare possibility of parliamentary government."

STV spread through the British Empire, leading it to be sometimes known as British Proportional Representation. In 1896, Andrew Inglis Clark was successful in persuading the Tasmanian House of Assembly to adopt what became known as the Hare-Clark system, named after himself and Thomas Hare.

In the late 1800s and 20th century, refinements were made to Hare's original system by Henry Richmond Droop, J.B. Gregory, Meek, Warren, Tideman, Wright and others.

Australia

Australia uses several forms of ranked votes in different jurisdictions. The systems require voters to rank several, or all, of the candidates on the ballot, reducing or eliminating the possibility of exhausted votes.

Lower house elections for the Australian parliament and for all states except Tasmania use what they call STV (what others call Instant-runoff voting to elect a single member for an electorate.

At the Commonwealth level (national level) and in most states, upper houses use STV to elect multiple members to represent a state or district.

The Hare-Clark STV system is used in Tasmania's House of Assembly and the Australian Capital Territory (ACT) Legislative Assembly. Hare Clark uses the Droop quota and the Gregory Method for transfer of surplus votes. During the count fractional votes are recorded under a separate heading for simplicity sake. On the ballot, candidates' names are placed within the column for each party and are randomised by Robson Rotation rather than alphabetical. Casual vacancies are filled by the countback method, which involves recounting the original ballots to elect one of the candidates who stood but failed to be elected in the last election.Newman, Hare-Clark in Tasmania

The Australian Senate and the upper houses of New South Wales, South Australia, Victoria and Western Australia use STV to elect multiple members with the option of voting "above the line". Queensland has a unicameral legislature — that is, it does not have an upper house.

The Group Voting Ticket or Ticket-Voting system is in use in Victoria, and was used in the Senate from 1984 to 2013, in New South Wales from 1987 to 2003 and in South Australia from 1985 to 2018. Western Australia used it from 1987 until the 2021 election, but legislation has been introduced to abolish it. The votes are counted in the basically same way as under Hare-Clark, but when casting votes, voters have the option of selecting one single group "above the line", instead of numbering individual candidates below the line. Groups of candidates (usually, but not inevitably, corresponding to political parties) may each pre-register one ranked list of all the candidates (or, in some systems, two lists) and the votes above the line for each ticket are deemed to have numbered the candidates in the order pre-specified on the team's list (if the team lodged two lists, 50% of the votes go to each version). Casual vacancies are usually filled by the house of parliament with the vacancy, though there may be a requirement by law or convention to select a nominee of the out-going member's party.

Where Group Voting Tickets are now abolished, an "above the line" vote is equivalent to a vote for all candidates in one group in order, but the elector may choose to number additional boxes to express preferences for other groups.

The Senate, News South Wales, South Australia, Victoria and Western Australia (pending legislation) allow optional preferential voting, so a voter does not have to complete every square.

Each form has its pros and cons. The Hare-Clark system with Robson Rotation is advocated on the grounds that the effect of 'donkey voting' is reduced because of the randomised ordering, and the absence of the group voting tickets creates more personal accountability. The alternative system is advocated on the grounds that informal voting (spoiled ballots) is reduced because only one number need be written; on the other hand, it greatly increases the potential for tactics by parties as they have direct control of a large percentage of the vote. Over 90% of voters vote "above the line" instead of ranking their own preferences in detail. As a result, the informal rate reduced from around 10 percent, to around three percent.

Jurisdiction Body elected "Above the line" Group tickets Vacancies Surplus votes transfer method Seats per constituency Year introduced Federal Parliament Senate Yes (1987–present) No (in use 1987–2016) Appointment All ballots at fractional value (Inclusive Gregory)Farrell and McAllister, The Australian Electoral System, p. 61 2 (ACT, NT) or 6 (states) (2 or 12 at a double dissolution) 1948 Australian Capital Territory Legislative Assembly No No Countback Last parcel of ballots at fractional value Gregory (simple) 5 1993 New South Wales Legislative Council Yes (1987–present) No (in use 1987–2003) Appointment (formerly highest runner-up of same team) Surplus ballots only at full value 21 1978 South Australia Legislative Council Yes (1985–present) No (in use 1985–2018) Appointment All ballots at fractional value (Inclusive Gregory) 11 1973 Tasmania House of Assembly No No Countback Last parcel of ballots at fractional value, Gregory (simple) 7 (previously 5) 1907 Victoria Legislative Council Yes (1988–present) Yes (1988–present) Election by joint sitting of Council and Assembly (must be from the same party if vacated member was elected under a party; otherwise, must be non-partisan) All ballots at fractional value (Inclusive Gregory) 5 Western Australia Legislative Council Yes (1987–present) No (in use 1987–2021) Countback All ballots at fractional value (Inclusive Gregory) 6 (37 (pending)) 1987

Canada

STV was used in provincial elections in two provinces and city elections in 20 cities and municipalities in the 1917 to 1971 period.Bowler and Grofman, Elections in Australia, Ireland and MaltaA Report on Alberta elections 1905-1982 All these elections used the Droop quota. For transfers of surplus votes, most of them used the whole vote method. Only Calgary city elections used the Gregory fractional method. STV was used in Winnipeg for provincial elections to elect ten MLAs from 1920 to 1949. Barring the short-lived experience of Ireland electing 19 in a contest in 1925, this was the largest District Magnitude (number of members elected in single contest) in any legislative election anywhere in the world until New South Wales began to elect 21 in its elections starting in 1990.Farrell and McAllister, The Australian Electoral System, p. 60

Jurisdiction Body elected "Above the line" Group tickets Vacancies Surplus Vote Transfer method Seats/constituency Year introduced Manitoba Legislative Assembly No, only votes for candidates allowed No Seat left empty until next general election Surplus ballots only, at full value 10 1920–1945 2 or 4 per district 1949, 1953 1920 (cancelled in 1955) Alberta Legislative Assembly No, only votes for candidates allowed No by-election (A Report on Alberta elections, 1905-1982 -- Edmonton (provincial electoral district)#1924 by-election, (Edmonton (provincial electoral district)#1936 by-election, (Edmonton (provincial electoral district)#1937 by-election, Edmonton (provincial electoral district)#1942 by-election Surplus ballots only, at full value Edmonton 5-7 Calgary 5–6 1924 (cancelled in 1956) Winnipeg Winnipeg City Council (aldermen) No No filled at next election (staggered terms) in by-election Surplus ballots only at full value 6 (3 per district elected in each election) 1920 (cancelled 1970) Calgary Calgary City Council (aldermen) No No next election (staggered terms) All ballots at fractional value (Inclusive Gregory) 1917-1960 6-9 (depending on resignations). 1960-1970 2 per district (1 per district elected in each election, unless extra empty seat due to resignation, etc.). 1971 2 per district 1917 (in use to 1961, then intermittently, replaced mostly by IRV, (depending on resignations) to 1971, 1971 STV used to elect all city councillors, in two-seat districts.Monto, When Canada Had "Effective Voting" Edmonton Edmonton City Council (aldermen) No No next election (staggered terms) Surplus ballots only, at full value 5-7 (depending on resignations) 1923 (cancelled in 1928)Rek, Municipal Elections in Edmonton

Other cities that used STV include Vancouver, Victoria, Nelson, Port Coquitlam, New Westminster, Saskatoon, Regina, Moose Jaw, North Battleford, St. Boniface and Lethbridge (1928 only).

Federal elections in Canada

Senate Under the proposed Bill C-43 before the Parliament of Canada during the 39th Parliament – 1st Session (April 3, 2006 – September 14, 2007), STV would have been used for consultative elections of Senators.

Alberta STV-PR was used in the Calgary and Edmonton electoral districts for electing Members of the Alberta Legislative Assembly from 1926 to 1955, with five, six or seven MLAs being elected at-large in each city. Medicine Hat used STV for the 1926 election only, electing two MLAs. Between 1924 and 1955, all other electoral districts used instant-runoff voting alternative voting / preferential voting. As well, by-elections held in Edmonton, Calgary and Winnipeg between 1924 and 1956 used IRV. In 1958 the cities were divided into many single-member constituencies, and all MLAs were elected in single-member first past the post elections.

As well, STV was used for city elections in Calgary from 1917 to 1961 and in 1971; Edmonton city elections from 1923 to 1927 and Lethbridge in 1928.

British Columbia Many British Columbia (BC) cities used multi-member at-large districts for their municipal elections at one point, including Vancouver, Victoria, New Westminster and Nelson. Two types of voting were used at different times - Plurality block voting during most periods, and between 1917 and 1926, many used the single transferable vote.