STV - the Single Transferable Vote

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The Single Transferable Vote (STV) is a form of Proportional Representation. It provides an alternative form of voting to the First Past the Post (FPP) system. It allows votes to be made for specific candidates, rather than just for party lists. Its main benefit is to reduce wasted votes for either very popular candidates or those with no chance of winning. STV can also be used with single-member constituencies, where it produces results similar to those of a two-round electoral system, with candidates being removed until a winner is found.

Currently the FPP system is used in Britain to decide political leaders. This system has the benefit of being simple, and it also provides a strong popular base for a leader. Every voter casts one vote for whoever they feel would make the best candidate; whichever candidate takes the most votes wins.

In the UK, for example, it is always raining; especially on a Thursday when the public votes1. Therefore those that struggle through the weather to get to a voting station would like to feel that their votes have mattered. However, all too often their vote turns out to be for the losing candidate. The STV system means that the chances of a winning candidate being the one that your vote was cast for, even if not as a first choice, would be much higher.

The STV system moves votes from their original candidates in the following two ways.

  • Very popular candidates who receive many 1st choice votes take as many as needed to be elected, and then any remaining votes are moved to other candidates.

  • The most unpopular candidates are discarded and any votes that they have received are redistributed to other, less unpopular, candidates.

How to Vote

Voting in an STV system requires all the standard things that you need to be eligible to vote normally2. The actions needed for this vary widely from country to country, but fulfilling them3 is necessary to receive your voting slip.

When you have finally made it to your voting booth, you will receive a voting slip with a list of candidates. You will then be told to rank your preferences. Here is how to do just that:

  • Decide who your favourite person on the list is.

  • Place a '1' in the box next to your primary candidate's name. This person is now your first choice.

  • Decide who your second favourite candidate is. There is still a fairly high chance of this vote being used, so spend some time and choose wisely.

  • Place a '2' next to this candidate's name.

  • Continue to pick and vote4 for as many candidates as you want to. It is not compulsory to make as many votes as there are candidates.

  • Place your voting slip in the ballot box and walk out of the booth knowing that you have fulfilled your democratic duty and have guarded your rights for another handful of years.

When Does it Stop?

The percentage of votes needed for a candidate to be selected (and so have their surplus votes redistributed) and the number of times votes must be redistributed depends on how many positions of power there are up for grabs.

The number of votes that are needed can be calculated by the Droop Quota:

Real Votes
+ 1


For example, say there are ten candidates contending for four places on the city council. There will be 1,200 people who decide to vote in this election. Votes = the number of the votes that are legitimate (non-spoiled). Therefore 1,200 votes are divided by five (four seats plus one). This means that 240 votes plus one are needed for each candidate to be elected. Any votes for a candidate above this threshold are redistributed.

The Election is Here!

Voters have to decide who their favourite candidates are out of the following candidates; the 1st and 2nd choices of the voters are shown below:

1st ChoiceTaffAunt LilMouseMouseProfHoggy
2nd ChoiceAunt LilTaffProfHoggyHoggyProf

Before we can do anything else we have to know how many votes are needed for each person to be "elected". So we must look back at the Droop formula – we are finding the three most voted for candidates. There are 27 votes so our formula looks something like this

27 divided by (3+1) plus 1
– this gives a requirement for eight votes needed for each person to be selected.

Only the first two choices of each voter are given here as that is all that is needed, but in larger elections with more seats decisions may be made by 3rd or even 4th place votes. As you can see, Mouse has two entries – that is because she has been voted as the first choice by two different groups who have then voted for different people as second choice.

CandidateTaffAunt LilMouseProfHoggy
  • Stage 1, Mouse receives 10 primary votes from group C and 4 from group D. This gives her 14 votes – far more than the minimum of 8 and so she is instantly elected.

  • Stage 2, Mouse's spare votes are distributed to the appropriate second choices, that is, Prof and Hoggy. No-one receives the required number of votes however so we move on to stage 3.

  • Stage 3, Aunt Lil has the least amount of votes so she is knocked out. All of her voters picked Taff as their second choice. Taff therefore has eight votes so is picked as the second candidate, however he has no excess votes to move to other candidates so stage 3 finished.

  • Stage 4, Hoggy has fewer votes than Prof so all his votes are awarded to Prof who then has more than eight votes so is the third and final candidate selected.

As we can see the STV system can cause a few confusing results. Mouse was selected by an overwhelming majority and then her voters continued to play an important role by how their secondary votes were apportioned. Taff was selected after receiving support from Aunt Lil's voters, thus proving that being a compromise candidate is an effective way of winning in STV elections. The strangest result here is Prof who despite only starting with 3 votes finished with 11 as the system defaulted to him at the end of the election.

Advantages of STV Elections

Like all Proportional Representational (PR) systems, STV is designed to give a greater relationship between voters' preferences and candidates elected. That is because they take 'wasted' votes – that is, votes for candidates who gain no benefit in having them – and allow voters to use them again for a second choice candidate.

The STV system has the advantage over most PR systems that it allows voters to choose not only between political parties (Conservatives, Labour, Lib Dems etc) but individual candidates inside those parties (David Cameron5, Grant Shapps6 etc) as well. This allows the electorate to have a more active say in who become their leaders.

STV also allows those who vote to influence how a coalition is formed between parties. The reason for this is because candidates with similar views will be placed near each other in voter preferences, thus increasing the chances of at least one of them gaining power. These leaders normally will seek out alliances with parties that were supported in the election by the same groups of voters.

Disadvantages of STV Elections

The STV system has been widely ridiculed as a very difficult system to comprehend. Voters seldom fully understand the subtleties of the system. This can be problematic as voters don't realise that they can make as many votes as they wish. Bullet voting – that is just making a single vote – is very common among voters accustomed to the FPP system.

Political parties have some say in where the boundaries for voting regions are set. This allows them to choose where they want to send their best candidates and exploit the STV system which makes it easy to win at least one seat in each area.

The STV system pits candidates in the same party against each other. This elimination of safe seats means that party loyalty disappears in the run up to an election. It also causes budgetary problems as each local party leadership has to choose how it wants to divvy up its funds. Party leadership has the issue of a lack of time for campaigning although it can demand that candidates in the same party go elsewhere.

One major problem is that the STV system allows parties which receive fewer votes to take a majority of the seats. This can be blocked with specific legislation but it is a loophole that can be exploited under certain circumstances. This problem can also be found in other, similar, PR methods.

Governments chosen by all methods of PR are normally weaker than those chosen by FPP methods. This can lead to a power vacuum requiring coalitions of several parties. Often the result of this is a lack of decision-making capability, preventing majorities being formed in parliamentary votes.

A History of STV

The first instance of a system of votes being transferable was brought into being by Thomas Wright Hill in 1821. Only 34 years later, this type of voting was used in a real election. Carl Andrae established a modified version to elect the Danish Rigsdagen7. A decade later, he used the same system to elect the other house in the Danish Parliament, the Landsting.

The first system that bears obvious similarity to the modern STV system was conceived by Thomas Hare in 1857. It is unknown whether he knew of Hill's concept and adapted it or independently thought of a similar idea. In his system, voters would be told which candidate received their final vote8 in order to more firmly connect voters with their leaders.

In 1896, the Tasmanian House of Assembly introduced the STV system, a method it still uses over a century later. They use the Hare-Clark method system which uses several methods to place the emphasis on the candidate rather than the party. The order that candidates appear on the cards is randomised and the handing out of 'how to vote' leaflets is banned. This makes it hard for parties to stress certain contenders but makes a difficult system even more complex. Australia in general also introduced the STV system for parts of its political system.

Modern Examples

There are a number of countries that currently use STV for various forms of elective government. These range from local councillor elections to that of the highest law-making body in the land. Below are a few examples of the countries that use STV, what they use it for and how it works.

  • Éire. The ROI uses the STV system for local, parliamentary, Presidential and European elections. The STV method has resulted in power being held by large coalitions; no single party has held a majority in Éire since 1977. The country's governance has been reasonably stable albeit with the typical lack of decisive control of a single-party leadership.

  • Malta. This little island state has used the STV system since it received its independence from Britain in 1964. It bucks the trend in that STV normally encourages the formation of many smaller parties while in Malta the country has almost formed a two party system. Malta uses the STV vote for MPs, local councillors, and MEPs. A stable and prosperous country, Malta benefits directly from the STV system.

  • UK. STV is used for European elections in Northern Ireland, for elections to the Northern Ireland Assembly, and local elections in Northern Ireland and Scotland. As is shown, the STV system is not used for all UK elections, where the FPP system is dominant.

1Elections in the UK these days tend to be called in May, in the hopes of sunnier weather and therefore a better turnout.2For example, in an FPP election.3Whatever they might be.4Remember to indicate your decreasing preference for each candidate or your vote will be considered void.5Conservative Prime Minister of UK as of May 2010.6Conservative Minister of State for Local Communities.7 A very short-lived house in the first Danish Parliament.8Current voting information allows this data to be found out by analysis.

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