Single transferable vote

How the Single Transferable Vote Works

The single transferable vote process begins with voters receiving a ballot listing candidates for a multi-member district. Each voter has one vote but can express their preferences by ranking candidates numerically, such as 1, 2, 3, and so on. Voters may rank as few or as many candidates as they wish, and they are free to rank candidates from different parties in any order. This candidate-centred approach gives voters precise control over which individuals they support.

Before counting, an electoral quota is calculated. This is the minimum number of votes required for a candidate to be guaranteed election. Common formulas include the Droop quota and the Hare quota. The Droop quota is more frequently used in real-world elections and is calculated by dividing the total valid votes by one more than the number of seats to be filled, then adding one. The counting proceeds in rounds. In the first round, each vote is allocated to the voter's first-preference candidate. Any candidate who reaches or exceeds the quota is immediately declared elected.

If an elected candidate has more votes than the quota, their surplus votes are transferred to other candidates. The method of transfer varies. Some systems, like Hare, Clark used in Tasmania, transfer fractional surpluses based on the last bundle of votes received. Others transfer whole votes. These surplus votes are distributed to the next available preference marked on those ballots. If no candidate reaches the quota after surplus transfers, the candidate with the fewest votes is eliminated. Their votes are then transferred to the next-preferred candidate on each ballot.

This cycle of electing candidates, transferring surpluses, and eliminating the least popular candidates continues until all seats are filled. Counting, eliminations, and vote transfers continue until enough candidates are declared elected, meaning all seats are filled by candidates reaching the quota. The count ends when there are only as many remaining candidates as there are unfilled seats, at which point the remaining candidates are declared elected. The process ensures votes are not wasted on candidates who cannot win or who have already secured enough votes. This allows a voter's support to flow to other choices through the transfer of their vote according to their ranked preferences.

Objectives and Proportional Outcomes

The primary objective of the single transferable vote is to produce proportional representation within multi-member districts. Proportionality is achieved because the quota acts as a proportional threshold. Any cohesive group of voters that can muster enough votes to meet the quota can elect a candidate. The larger the district magnitude, meaning the more seats available in a district, the lower the percentage of the vote needed to elect a representative. This makes it possible for significant minority viewpoints to win seats.

STV aims to maximize the number of effective votes, meaning votes that directly contribute to electing a candidate. Under non-proportional, winner-take-all systems, votes for losing candidates or surplus votes for winning candidates are often wasted. In STV, these votes are transferred and put to use. This means most voters can see their vote help elect someone they ranked, even if not their first choice, leading to broader voter satisfaction. The system also tends to produce mixed representation within a district, often electing members from different parties.

The system naturally limits the dominance of a single party. Unlike first-past-the-post or block voting systems where one party can sweep all seats in a district with a simple plurality, STV makes it difficult for any party to win all seats unless it receives an overwhelming majority of votes. This results in legislative bodies that more closely mirror the overall distribution of voter preferences. Furthermore, because voters rank individual candidates, STV promotes intra-party competition and can lead to more diverse representation in terms of candidate background and ideology beyond simple party labels.

Comparison with Other Electoral Systems

The single transferable vote differs fundamentally from Canada's current first-past-the-post (FPTP) system. FPTP uses single-member districts where the candidate with the most votes wins, often leading to disproportionate outcomes where a party's share of seats does not match its share of the popular vote. STV uses multi-member districts and ranked ballots to achieve proportionality. It is also distinct from the alternative vote, or instant-runoff voting, which uses ranked ballots but in single-winner elections and does not produce proportional results.

STV is often contrasted with party-list proportional representation systems. In closed-list systems, voters choose a party, and the party determines the order of candidates who fill the seats it wins. STV is a candidate-based system where voters choose between individuals, not just parties. This gives voters direct influence over which specific candidates from a party are elected. STV also differs from the single non-transferable vote, a semi-proportional system where voters cast a single vote in a multi-member district but votes are not ranked or transferred, often leading to less precise proportionality.

Compared to plurality block voting, where voters have as many votes as there are seats and the candidates with the most votes win, STV provides far fairer outcomes. Block voting can allow a cohesive majority group to win every seat, completely excluding minorities. STV's transfer mechanism and quota prevent this. The system's ability to transfer votes across party lines based on voter preference also sets it apart from most list systems, where votes are typically confined to a single party's slate of candidates.

Variants and Implementation Details

Several variants of the single transferable vote exist, distinguished by their rules for transferring surplus votes and ballot structure. A key difference is the method of surplus transfer. The Gregory method, used in the Hare, Clark systems of Tasmania and the Australian Capital Territory, transfers fractional surpluses. When a candidate is elected with a surplus, only a fraction of the value of each vote in their last-received bundle is transferred to the next preference. This method is precise and non-random. In contrast, systems in Ireland and Malta transfer whole votes, which can introduce an element of randomness depending on which bundle of ballots is selected for transfer.

Another distinction is the use of ticket or party box voting. Some STV systems, particularly for upper houses in Australia, allow voters to simply select a party preference, which then applies a pre-determined party ranking to the ballot. Most pure STV systems, including those in Ireland, Malta, and Hare, Clark, do not allow this. Voters must rank individual candidates themselves. Ballot rules also vary regarding compulsory ranking. Some systems require voters to rank a minimum number of candidates for their vote to be valid, while others use optional preferential voting where voters may rank only one candidate if they wish.

District magnitude is a critical design choice. STV can work with districts electing as few as three or four members, though proportionality improves with larger magnitudes. The British Columbia Citizens' Assembly recommended districts electing between two and seven members, with the number varying based on geography and community integrity. Furthermore, systems differ in how they fill casual vacancies, such as through by-elections or by appointing the next-unelected candidate from the original count. These technical choices significantly impact the system's operation and outcomes in practice.

Use in Canada and Reform Proposals

The single transferable vote has a historical connection to Canadian politics. For three decades in the mid-20th century, a form of STV was used to elect provincial legislators in the cities of Winnipeg, Calgary, and Edmonton. This experience demonstrated the system's viability in a Canadian context, producing legislatures with more diverse party representation than would have been possible under first-past-the-post. The system was eventually abandoned amid broader electoral reforms.

In the modern era, STV re-emerged as a major proposal for electoral reform. The British Columbia Citizens' Assembly on Electoral Reform, convened in 2004, extensively studied different systems. The assembly's top values were proportional representation, local representation, and voter choice. After deliberation, the assembly recommended a model called BC-STV, a variant of the single transferable vote tailored to the province.

Subsequent reform efforts in other provinces, including Prince Edward Island and Ontario, have also featured STV as an option, though none have succeeded in adopting it to date. Advocacy groups continue to promote proportional ranked choice voting as a solution to disproportionate election results and voter dissatisfaction. The system is often highlighted for its ability to maintain local representation through multi-member districts while achieving proportionality. This combination is seen as attractive in Canada's geographically vast and politically diverse federation. Every substantial group within a district wins at least one seat, and the more seats the district has, the smaller the size of the group needed to elect a member.

International Examples and Adoption

The single transferable vote is used for national parliamentary elections in two countries: Ireland and Malta. In Ireland, STV is used to elect members to the Dáil Éireann, the lower house of parliament. It has fostered a political landscape with a strong focus on local constituency service and has generally produced coalition governments. Malta also uses STV for its unicameral parliament, with similarly stable results and a strong two-party dynamic supplemented by minor party representation.

At the sub-national level, STV is well established in Australia. The Hare, Clark system, a specific variant of STV, is used for elections in the state of Tasmania and the Australian Capital Territory legislative assemblies. In the United Kingdom, STV is used for local elections in Scotland and for electing the Northern Ireland Assembly. These examples show the system's adaptability to different political cultures and scales of government.

Recent adoption trends show interest in STV for municipal elections. The city of Portland, Oregon, adopted proportional ranked choice voting for its city council elections in 2026. This move reflects a growing interest in systems that promote representation of diverse communities in local government. The system's use in these varied jurisdictions provides a rich body of evidence on its operation, demonstrating its capacity to deliver proportional results, high voter satisfaction, and robust local representation.

Advantages and Criticisms

Proponents of the single transferable vote cite several advantages. The system delivers a high degree of proportional representation, making election outcomes fairer and ensuring most voters have an MP who reflects their views. It minimizes wasted votes by transferring them to subsequent preferences. STV gives voters significant choice and control, allowing them to express preferences both within and across party lines. It also promotes the election of independents and fosters intra-party competition, which can make representatives more accountable to constituents rather than just party leadership.

Supporters also argue that STV maintains a strong link between representatives and geographic constituencies, as MPs are still elected from specific multi-member districts. This addresses a common concern about pure party-list systems where the connection to a local area can be weak. Under STV, voters vote for candidates rather than for parties, as is the case in closed list proportional representation. Furthermore, the system tends to produce more collaborative politics, as candidates may seek second and third preference votes from voters of other parties. This is possible because a vote may be transferred across party lines to a candidate on a different party slate if that is how the voter marked their preferences.

Critics of STV point to its complexity, particularly in the counting process, which can be difficult for the public to understand fully. They argue that the system can lead to very large constituencies, potentially weakening the local community connection, especially in rural areas. Some also contend that the intra-party competition it encourages can lead to factionalism. Another criticism is that the system may produce unstable coalition governments, though evidence from Ireland and Malta shows generally stable administrations. Finally, the strategic marking of rankings can be complex for voters, though optional preferential voting mitigates this concern by allowing voters to rank only one candidate if they prefer.

Questions about Single transferable vote

How does STV differ from the ranked ballots used in mayoral elections?

Ranked ballots in single-winner elections, like for a mayor, use a system called instant-runoff voting or the alternative vote. That system ensures the winner has majority support but does not produce proportional results. STV uses ranked ballots in multi-winner elections to achieve proportionality. While both use rankings, their objectives and outcomes are different. STV is designed for electing a team of representatives where multiple viewpoints can win seats.

Does STV require increasing the number of MPs?

No, STV does not inherently require more MPs. It works by combining existing single-member ridings into larger multi-member districts. For example, three current ridings could be combined into one new district that elects three MPs. The British Columbia Citizens' Assembly recommended districts that would elect between two and seven MLAs, with the number varying based on geography and community ties, keeping the total number of legislators the same.

Where is STV used in the world today?

STV is used for national parliamentary elections in Ireland and Malta. It is used for state elections in Tasmania and the Australian Capital Territory in Australia, and for local elections in Scotland. It was also recently adopted for city council elections in Portland, Oregon, in 2026. These examples demonstrate its application in a variety of democratic contexts, from small island nations to sub-national legislatures and large cities.

What is the single transferable vote (STV)?

The single transferable vote is a multi winner proportional representation electoral system. In STV, each voter casts a single vote using a ranked ballot. Voters rank candidates in order of preference, and votes may be transferred to subsequent preferences if a candidate is eliminated or elected with surplus votes. This system aims to produce proportional results so that each vote has roughly equal value in electing representatives.

How does the STV voting process work?

In STV, a voter ranks candidates on their ballot. A quota, such as the Hare or Droop quota, is calculated to determine the minimum votes needed to win. Candidates meeting the quota are elected. If seats remain, surplus votes from elected candidates are transferred to voters' next preferences. If no surpluses exist, the least popular candidate is eliminated and their votes are transferred. This counting and transfer process continues until all seats are filled.

What are the main goals of the STV system?

STV aims to achieve proportional representation within an electoral district. It ensures that substantial groups win at least one seat, with more seats allowing smaller groups to gain representation. The system seeks to make most votes count toward electing a candidate, reducing wasted votes. It also promotes fairness, where a party with twice the votes of another generally wins twice the number of seats.

Sources: Wikipedia and current public reporting, checked by the Nosy Mag desk. Last updated 2026-10-20.