Proportional Representation (PR) is the principle behind a number of electoral systems, all of which attempt to ensure that the outcome of the election reflects the proportion of support gained by each competing group.
PR contrasts to the Majoritarian principle, where whichever party or candidate obtains a plurality of votes within any given constituency wins that contest outright. Majoritarianism is the principle that underpins the First-Past-The-Post system that is used for elections to the House of Commons, along with other systems including alternative vote, bloc vote and various single member constituency systems.
Similarly, there are a number of different systems based on PR. A simple party-list PR system is used in the UK for the European Parliament. A different Additional Member System (AMS) is used to elect the Scottish parliament and the Welsh Assembly. There are several important differences and the principle of proportionality is applied quite differently between the two.
The single transferable vote system is used to elect the district councils (since 1973) and the MEPs in Northern Ireland, and the local government councils in Scotland (since 2007).
The extent to which an electoral system is PR-based depends on the number of candidates elected per constituency and the existence of any thresholds for successful election. A number of electoral systems combine elements of both, such as the single non-transferable vote and cumulative voting systems.
PR is a relative novelty in British politics, although it has long been used in Europe and went through a spell of popularity in some circles in the late 19th century. There were several attempts to introduce PR voting for the UK parliament during the early 1900s and there were several more reviews of the topic. The University members of the UK parliament were elected by STV-PR until this special category of MP was abolished. More recently, support for PR has been growing since the 1970s, and its leading champions in the UK are the Liberal Democrats.
The growth in support for PR has stemmed largely from recent concerns about the First Past the Post system. In the 1970s, First Past the Post failed to produce the strong majority accountable governments that was said to be one of the key points in favour of the system. And throughout the 1980s, the growth of the third party share of the vote increasingly showed the handicaps of the First Past the Post system on parties other than the Conservatives and Labour.
For example, in Labour's 1997 election landslide, the Liberal Democrats secured 16.8 per cent of the total national vote, but won fewer than 10 per cent of the seats.
Labour promised a referendum on PR on coming to power in 1997, ostensibly as a result of an agreement with the Liberal Democrats, but nothing materialised. However, a combination of PR and First Past The Post (the Additional Member System) was used for the elections to the Scottish Parliament and the Welsh National Assembly, and the electoral system for the European Parliament was changed to a closed party list PR system.
In the Scottish elections of 1999 and 2003, and the Welsh elections of 1999, the electoral system failed to return an absolute majority for any one party, requiring coalition administrations to be formed.
Following the General Election in May 2010, one of the concessions the Liberal Democrats secured from the Conservatives as part of the deal to form a coalition government was that a referendum would be held on the AV voting system.
Subsequently, on 5th May 2011 an election was held on the voting system used to elect MPs to the House of Commons. In the event the electorate decided by a substantial majority to reject the proposal to change from the 'first past the post' system to the AV system.
Arguments cited in favour of a change from First Past the Post to PR include:
The fairer treatment of minority parties and independent candidates
Fewer votes are 'wasted', as more people's preferences are taken into account
Greater effective choice for voters. By reducing the dominance of the large parties, PR may encourage turn-out and reduce apathy
By rarely producing an absolute majority for one party, PR ensures greater continuity of government and requires greater consensus in policy-making.
Arguments cited against PR include:
PR provides a route for extremists into the political mainstream, who would otherwise be excluded by the structure of FPTP
PR produces 'weak' coalition governments rather than 'strong' majority governments, which can lead to indecision, compromise and even legislative paralysis. It can also reduce accountability to voters, as an ousted party of government can reinstall itself by finding new coalition partners after an election
The adoption of list systems breaks the link between the elected representative and his or her constituency
The greater complexity and choice that PR allows can put voters off voting, by requiring them to have a greater knowledge of individual and party positions.
There is also an institutional paradox built into the British political system, working against the adoption of Proportional Representation. Any party that comes to power under First Past The Post is likely to appreciate the advantages that it gives to the government: a strong mandate, (usually) a lack of coalition partners, and considerable freedom of action. Therefore, arrival in government under First Past The Post is likely to dampen any party's enthusiasm for PR - as some suggested was the case with Labour in 1997.
However, the Coalition government elected in May 2010 agreed that the electorate should be allowed to decide, in a referendum scheduled for May 2011, whether the UK should adopt the 'alternative vote' system instead of the current 'first past the post' system for electing Members of Parliament to the House of Commons. Although the Conservatives have traditionally been opposed to changing from FPTP, they acceded to the Liberal Democrats' demand for a referendum on voting reform as part of the deal to secure a coalition government.
But in order for the referendum to take place in May, the Parliamentary Voting System and Constituencies Bill had to be passed by 16th February according to Electoral Commission rules and the Opposition appeared to be intent on blocking the legislation.
Labour objected to other provisions in the bill which would reduce the number of MPs from 650 to 600 and involve boundary changes which they believed would disadvantage their party. They therefore called for the other provisions to be removed before they would support the bill and allow a referendum to take place. Labour peers were also accused of "dragging their feet", subjecting the bill to unnecessary lengthy debate in the House of Lords in an attempt to slow its progress. However, the Government remained adamant that the bill would be passed in time.
And finally, following a marathon debate in both Houses, 110 hours in committee and several sessions of 'ping pong', the Parliamentary Voting Systems and Constituencies Bill received Royal Assent just before midnight on the 16th February 2011.
Party Lists: (proportional)
Party list systems have two main forms - open and closed. Each party provides a list of candidates. With the open system, voters put a cross by the name of a candidate; with the closed system they put a cross by the name of a party. Voters have only one vote and seats are allocated in proportion to the number of votes received.
List PR is used to elect candidates in multi-member districts, or sometimes in an entire country. Party list systems vary considerably across the globe, determined chiefly by the size of districts, thresholds for securing seats and the manner in which the seats are allocated.
There are a number of methods used to translate votes into seat allocation. The most common are the d'Hondt method, the Sainte-Lague method, the Huntington-Hill method and the largest remainder (LR) method.
Where used: Party lists are the most common method of election in the world. Places where they are used include British elections to the European Parliament (excluding Northern Ireland, which uses STV); Israel's Parliament, the Knesset; and The Netherlands' Second Chamber.
Single Transferable Vote (STV): (semi-proportional)
STV uses preferential voting in multi-member constituencies. Each voter has one vote. This vote can transfer from the voter's first preference, to second preference and so on if the voter's preferred candidate has no chance of being elected or has enough votes already. Candidates do not need a majority of votes to be elected, just a known 'quota' or share of the votes determined by the size of the electorate and the number of positions to be filled.
Where used: Republic of Ireland - all elections except for the presidency and by-elections when Alternative Vote is used; Northern Ireland - Assembly, European and local government elections; Scotland - local elections from 2007; Malta - all elections; Australian Senate; Tasmanian House of Assembly; New Zealand - various local authorities; India - the indirect elections to the Rajya Sabha, the upper house of India's federal Parliament.
Additional Member System: (hybrid)
AMS is a hybrid voting system, part First Past The Post and part closed party list, the party list element added on to make the result more proportional. Outside the UK it is more commonly referred to as Mixed Member Proportional (MMP).The exact proportion of constituency representatives and list representatives varies from country to country; the constituency element usually makes up between 50 and 80 per cent. Voters typically have two votes - one for a candidate and one for a party.
When all the votes are in, each constituency returns a winner, in the traditional FPTP style. If a candidate was standing in a constituency as well as on a party list, their name is taken off the list, with everyone below them moving up a place. The additional members are then allocated with the aim of tallying the number of seats won by each party to their share of the vote. Some systems do this solely on the basis of the party vote, others include the constituency vote too.
Where used: Scottish Parliament; Welsh Assembly; Greater London Assembly; Italy - Senate and Chamber of Deputies; Germany - Bundestag; New Zealand - House of Representatives; Mexico - Camara de Diputados (lower house); Bolivia - Camara de Diputados (lower house); Lesotho - National Assembly (lower house).
First Past The Post: (majoritarian)
First Past The Post voting, currently used to elect members of the House of Commons, takes place in single-member constituencies. The voter simply puts a cross in a box next to one candidate. The candidate with the most votes in the constituency wins. All other votes count for nothing. In some places, such as a number of English and Welsh local elections, FPTP is used to elect several representatives at one time. This system is known as the Multiple Non-Transferable Vote (MNTV).
FPTP is also known as simple majority voting or plurality voting.
Where used: FPTP is the second most widely used voting system in the world, after party lists. Countries which use this system include the UK, the US, Canada and India.
The Limited Vote: (majoritarian)
The Limited Vote is used in multi-member constituencies. It allows each elector more than one vote, but fewer votes than there are candidates to choose from. The candidates with the most votes get elected.
Where used: The Spanish Senate; Gibraltar's House of Assembly, where electors have eight votes for the 15 seats; various local-level elections, such as those for municipal offices in some US States.
Alternative Vote: (majoritarian)
The Alternative Vote (AV) is very much like First Past The Post. It is used to elect representatives for single-member constituencies, but rather than simply marking a solitary 'X' on the ballot paper, the voter has the chance to rank the candidates on offer by putting a '1' by their first preference, a '2' by their second preference and so on.
If a candidate receives a majority of first-preference votes (more people put them as number one than all the rest combined), then they are elected. If no candidate gains a majority on first preferences, then the second-preference votes of the candidate who finished last on the first count are redistributed. This process is repeated until someone gets over 50 per cent.
AV is also known as Instant Run-off Voting (IRV), Ranked Choice Voting (RCV) and Preferential Voting.
Where used: Australian House of Representatives; Australian Legislative Assemblies ("lower houses") of all states and territories (bar Tasmania and the Australian Capital Territory, which both use STV); Australian Legislative Council in Tasmania; Irish Presidential election; By-elections to the Dáil (the lower house of the Irish Parliament); By-elections to the Northern Ireland Assembly; Papua New Guinea National Parliament; Fijian House of Representatives; numerous American Mayoral and district elections; Student Union elections.
Alternative Vote Plus:
The Alternative Vote Plus (AV+) was invented by the 1998 Independent Commission on the Voting System, commonly known as the Jenkins Commission. The Commission described the system as a "limited" form of AMS aimed at achieving a balance between the requirements of "broad proportionality" and "stable government".
AV+ was created with the intention of being the alternative to First-Past-the-Post (FPTP) in Labour's promised referendum on the voting system for the House of Commons. The referendum never came and AV+ has, for now, been confined to the parliamentary archives.
Supplementary Vote (SV):
The SV system is similar to the Alternative Vote system, but under SV voters are limited to a first and second preference only. All first choice votes are tallied and if the candidate has a majority they are elected. If no candidate receives a majority, the top two candidates are retained, and the rest eliminated. The second-preference votes of the eliminated candidates are then counted, and any for either of the top two candidates are added to their first-round totals. Whichever candidate has the most votes after these second-preferences have been allocated is declared the winner.
Where used: Directly elected English mayors, most notably the Mayor of London.
Source: Electoral Reform Society
Turnout at the 2010 UK general election was 65.1%. This represents an improvement on the turnout at the 2005 general election which saw figures of 61.4%. Turnout at the 2001 general election was 59.4% - the lowest figures since 1918.
Turnout at the local elections in May 2010 was 62.2%. The unusually high turnout could be explained as a result of the local elections being combined with the UK general election. Local election turnout in 2009 was 39.1%, marginally lower than the 2008 average of 39.9%.
Average turnout in the UK at the European Parliamentary elections in June 2009 was 34.7%. At the 2004 elections it was approximately 38.5%, 14.5 percentage points higher than in 1999 when the UK had the lowest turnout of any member state.
Recent elections have shown slight increases in turnout but voting levels are still not as high as they were in the last half of the twentieth century.
According to the Office for National Statistics, there were 44,260,051 Parliamentary electors registered to vote in Great Britain as at 1 December 2009. This is a rise of 200,585 (0.5 per cent) on the previous year.
Source: Electoral Commission
"The Government believes that our political system is broken. We urgently need fundamental political reform, including a referendum on electoral reform, much greater co-operation across party lines, and changes to our political system to make it far more transparent and accountable."
"We will bring forward a Referendum Bill on electoral reform, which includes provision for the introduction of the Alternative Vote in the event of a positive result in the referendum, as well as for the creation of fewer and more equal sized constituencies. We will whip both Parliamentary parties in both Houses to support a simple majority referendum on the Alternative Vote, without prejudice to the positions parties will take during such a referendum."
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