|Part of the Politics series|
Proportional representation (PR) is a concept in voting systems used to elect an assembly or council. PR means that the number of seats won by a party or group of candidates is proportionate to the number of votes received. For example, under a PR voting system, if 30% of voters support a particular party then roughly 30% of seats will be won by that party. PR is an alternative to voting systems based on single-member districts or on bloc voting; these non-PR systems tend to produce disproportionate outcomes and to have a bias in favour of larger political groups. PR systems tend to produce a proliferation of political parties. There are many different forms of proportional representation. Some are focused solely on achieving the proportional representation of different political parties (such as list PR) while others permit the voter to choose between individual candidates (such as STV-PR). The degree of proportionality also varies; it is determined by factors such as the precise formula used to allocate seats, the number of seats in each constituency or in the elected body as a whole, and the level of any minimum threshold for election.
Debate about proportionality 
Proportional systems emphasize the political agenda by parties, since parties often function at the heart of proportional representation. For example, a party that receives 15% of the votes under such a system receives 15% of the seats for its candidates. However, nations with proportional voting may differ in that some emphasize the individuals within the parties, such as the system in the Netherlands, while other nations only allow voting for parties, such as in the Spanish electoral system.
The majority of debate about voting systems is about whether to move to more proportionality. This is because the established parties in current US and UK elections can, and most often do, win formal control of the parliament with support from as little as 20-25% of eligible voters, at the cost of smaller parties. In Canada the situation is arguably more biased, with governments regularly formed by parties with support of under 40% of actual voters holding majority power for full four-year terms. Coupled with turnout levels in the electorate of less than 60%, this can lead to a party obtaining a majority government by convincing as few as one quarter of the electorate to vote for them.
Party-list proportional representation is one approach, in which each political party presents its list of candidates: voters chose a party list. The open list form allows the voter to influence the election of individual candidates within a party list. The closed list approach does not: the party chooses the order with its highest ranked candidates more likely to be elected.
Another variation is the single transferable vote (STV) which does not depend on political parties. Voters rank candidates in order of preference: if their most preferred candidate receives insufficient votes, the vote is transferred to the second choice and so on. Elections for the Australian Senate use what is referred to as above-the-line voting where candidates for each party are grouped on the ballot, allowing the voter to vote for the group or for a candidate. In elections to the Irish Dáil Éireann, candidates are listed on the ballot in alphabetic order, irrespective of party affiliation.
Party list proportional representation 
The parties each list their candidates according to that party's determination of priorities. In closed list systems, voters vote for a list of candidates, with the party choosing the order of candidates on the list and thus, in effect, their probability of being elected. Each party is allocated seats in proportion to the number of votes it receives, using the party-determined ranking order. In a local list system, parties divide in single member-like constituencies their candidates, which are ranked inside each general party-list depending by their percentages. This method allow electors to judge every single candidate as it happens in a FPTP system. In an open list, voters may vote, depending on the model, for one person, or for two, or indicate their order of preference within the list – nevertheless the number of candidates elected from the list is determined by the number of votes the list receives.
This system is used in many countries, including Finland (open list), Latvia (open list), Sweden (open list), Israel (national closed list), Brazil (open list), the Netherlands (open list), Russia (closed list), South Africa (closed list), Democratic Republic of the Congo (open list). For elections to the European Parliament, most member states use open lists; but most large EU countries use closed lists, so that the majority of EP seats are distributed by those. Local lists were used to elect the Italian Senate during the second half of the 20th century.
An alternative method is the mixed member system, which combine a national or regional proportional mechanism with single seat constituencies elected by a single winner system, attempting to achieve some of the positive features of each. Mixed systems are often helpful in countries with large populations, since they balance local and national concerns. They are used in nations with diverse geographic, social, cultural and economic issues. Such systems, or variations of them, are used in Germany, Lesotho, Mexico, Bolivia and New Zealand.
Single transferable vote 
This system uses single transferable vote, a ranked voting system. Each constituency elects two or more representatives per electorate. Consequently the constituency is equivalent in size to the sum of single member constituencies that would produce the same number of representatives. Parties tend to offer as many candidates as they optimistically could expect to win: major parties nominate more than minor parties. Voters rank some or all candidates in order of their choice. A successful candidate must achieve a quota, which is "calculated by dividing the Total Valid Poll by one more than the number of seats to be filled, ignoring any remainder and then adding 1 vote." Only in a few cases is this achieved at the first count. For the second count, if a candidate wins election her/his surplus vote (in excess of the quota) is transferred to the voters' second choices; otherwise, the least popular candidate is eliminated and those votes are redistributed according to the second preference shown on them. If more than one candidate cannot get enough votes after the transfer of votes of the least popular candidate, that candidate is also eliminated (as they would be eliminated on the next round anyway.)
The process repeats until all seats are filled either when the required number of candidates achieve the quota or until the number of remaining candidates matches the number of remaining seats. Although the counting process is complicated, voting is clear and most voters get at least one of their preferences elected.
All deputies are answerable directly to their local constituents. Some political scientists argue that STV is more properly classified as 'semi-proportional' as there is no assurance of a proportional result at a national level. Indeed, many advocates of STV argue that preventing nationwide proportionality is one of the primary goals of the system, to avoid the perceived risks of a fragmented legislature.
This system is used in the Upper House in India, Australia (Senate, Tasmanian and Australian Capital Territory Houses of Assembly and the Legislative Councils in New South Wales, South Australia, Western Australia and Victoria), Ireland, Northern Ireland (assembly, local government and European elections, but not national), Malta, local government elections in Scotland and selected (optional) local governments in New Zealand.
The British schoolmaster Thomas Wright Hill is credited as inventor of the single transferable vote, the use of which he described in 1821 for application in elections at his school. The method, which guarantees proportional representation, was introduced in 1840 by his son Rowland Hill into the public election for the Adelaide City Council. Unlike several later systems, this did not allow for party-list proportional representation.
Single Transferable Vote was first used in Denmark in 1857, making STV the oldest PR system, but the system used there never really spread. STV was re-invented (apparently independently) in the UK, but the British parliament rejected it.
A party-list proportional representation system was first devised and described in 1878 by Victor D'Hondt of Belgium. The procedure, known as the D'Hondt method, is still widely used. Victor Considérant, a utopian socialist, devised a similar system in an 1892 book. Some Swiss cantons (beginning with Ticino in 1890) preceded Belgium which was the first to adopt list-PR in 1900 for its national parliament. Many European countries adopted similar systems during or after World War I.
STV was used in Tasmania in 1907. In the last Irish elections to the UK Parliament in 1919, STV was used in the University of Dublin constituency; two Independent Unionists were elected. STV has been in use since Irish independence. A mainly centrist party, Fianna Fáil, typically receives 30%-50% of the vote while opposition parties, traditionally the centre-right Fine Gael and the centre-left Labour Party, are comparatively weak. This has led to a series of coalition governments; there has not been a single-party government since 1989.
PR is used by more nations than the single winner system, and it dominates Europe, including Germany, most of northern and eastern Europe, and is used for European Parliament elections (as enforced by EU law). France adopted PR at the end of World War II, but discarded it in 1958. In 1986 it was used for parliament elections.
Proportional representation is less common in English-speaking world; New Zealand adopted it in 1993, becoming the sole English-speaking country to use it. PR has some history in the United States. Many cities, including New York City, once used it to break up the Democratic Party monopolies on elective office. Cincinnati, Ohio, adopted PR in 1925 to get rid of a Republican Party monopoly, but the Republicans returned the city to FPTP in 1957. From 1870 to 1980, Illinois used a semi-proportional cumulative voting system to elect its House of Representatives. Each district across the state elected both Republicans and Democrats year-after-year. Cambridge, Massachusetts and Peoria, Illinois continue to use PR. San Francisco had city-wide elections where people would cast votes for five or six candidates simultaneously, delivering some of the benefits of proportional representation.
Switzerland has the largest use of proportional representation, which is the system to elect not only national legislatures and local councils, but also all local executives.
District magnitude 
Some nations with proportional elections, like Israel and the Netherlands, have one electoral district only: the entire nation, and the entire pie is cut up according to the entire outcome. Most nations have district systems in place where more than one person is elected per district. The constituency or district magnitude (DM) of a system is therefore measured by the number of seats per constituency. The greater the number of seats in a constituency, the more proportional the outcome will be. PR applied to a single-member district (SMD) is by necessity majoritarian. If the constituency is in a jurisdiction using list PR in its multimember districts (MMDs) the winning candidate needs a relative majority of the votes to win, so that the election in the SMD is by first-past-the-post. If the constituency is in a jurisdiction using PR-STV in its MMDs, an absolute majority of 50% plus 1 will likely be the minimum required for victory (depending on which quota is used) so that the election in the SMD is by the alternative vote. Four elected officials per district delivers a threshold of 20% (1/M+1) to gain a single seat. However, constituency borders can still be gerrymandered to reduce proportionality. This may be achieved by creating "majority-minority" constituencies - constituencies in which the majority is formed by a group of voters that are in the minority at a higher level. Proportional representation with the entire nation electing the single body cannot be gerrymandered.
Multimember districts do not necessarily ensure that an electoral system will be proportional. The block vote can result in "super-majoritarian" results in which geographical variations can create majority-minority districts that become subsumed into the larger districts. Also, a party that does not run enough people to fill all the seats it wins may be given those unfilled seats. This is termed an underhang.
Some nations, with either exclusively proportional representation or mixed-member systems, require a party list to achieve an election threshold—a set minimum percentage of votes to receive any seats. Typically, this lower limit is between two and five percent of the number of votes cast. Parties who do not reach that support are not represented in parliament, making majorities, coalitions and thus governments easier to achieve. Proponents of election thresholds argue that they discourage fragmentation, disproportionate power, or extremist parties. Opponents of thresholds argue that they unfairly redirect support from minor parties, giving parties which cross the threshold disproportionate numbers of seats and creating the possibility that a party or coalition will assume control of the legislature without gaining a majority of votes.
The most common way of measuring proportionality is the Gallagher Index.
Israel is a notable example of nationwide proportionally-elected Parliament which happens to be highly fragmented, with currently 14 parties. The balance of power is then in the hands of party leaders who form coalitions to unite and create a representative government.
To respond to this problem, Israel has tried multiple strategies:
- Raising the electoral threshold from 1% (until 1992) to 1.5% (until 2004), then 2% (took effect in Israeli legislative election, 2006)
- Prime ministerial elections, in order to give the PM popular support and strengthen his role in government. Voted in 1992, it was tried three times (in 1996, 1999 and 2001)
- Very large coalitions, representing a supermajority larger than the absolute majority (61 seats), and thus giving the coalition's main fraction (the Prime minister's) more options. Netanyahu's 2009 cabinet had the potential support of 74 of the 120 MPs.
List of countries using proportional representation 
This is a list of countries using proportional representation for central government.
|Australia||For Senate only, Single Transferable Vote|
|Austria||Party list, 4% threshold|
|Bolivia||Mixed member proportional|
|Bosnia and Herzegovina||Party list|
|Bulgaria||Party list, 4% threshold|
|Burkina Faso||Party list|
|Cape Verde||Party list|
|Costa Rica||Party list|
|Croatia||Party list, 5% threshold|
|Czech Republic||Party list, 5% threshold|
|Democratic Republic of the Congo||Mixed member proportional|
|Dominican Republic||Party list|
|Equatorial Guinea||Party list|
|Estonia||Party list, 5% threshold|
|Germany||Mixed member proportional, 5% (or 3 district winners) threshold|
|Hong Kong||Party list|
|Hungary||Mixed member proportional|
|India||For Upper House (Rajya Sabha) only, Single Transferable Vote by State Legislatures|
|Ireland||Single Transferable Vote (For Dáil only)|
|Israel||Party list, 2% threshold|
|Japan||Mixed member proportional|
|Latvia||Party list, 5% threshold|
|Lesotho||Mixed member proportional|
|Liechtenstein||Party list, 8% threshold|
|Macedonia [dead link]|
|Malta||Single Transferable Vote|
|Mexico||Mixed member proportional|
|Morocco||Party list, 6% threshold|
|New Caledonia||Party list|
|New Zealand||Mixed member proportional, 5% threshold|
|Northern Ireland||Single Transferable Vote|
|Poland||Party list, 5% threshold|
|Romania||Mixed member proportional, 5% threshold|
|San Marino||Party list|
|Sao Tome and Principe||Party list|
|Sint Maarten||Party list|
|Slovakia||Party list, 5% threshold|
|Slovenia||Party list, 4% threshold|
|South Africa||Party list|
|South Korea||Mixed member proportional, 3% (or 5 district winners) threshold|
|Spain||Party list, 3% threshold in small constituencies|
|Sri Lanka||Party list|
|Sweden||Party list, 4% threshold|
|Taiwan||Mixed member proportional|
|Thailand||Mixed member proportional|
|Turkey||Party list, 10% threshold|
|Venezuela||Mixed member proportional|
|Wallis and Futuna||Party list|
Further reading 
- Amy, Douglas J. (1993). Real Choices/New Voices: The Case for Proportional Representation Elections in the United States. Columbia University Press.
- Denis Pilon (2007). The Politics of Voting. Edmond Montgomery Publications.
- Colomer, Josep M. (2003). Political Institutions. Oxford University Press.
- Colomer, Josep M., ed. (2004). Handbook of Electoral System Choice. Palgrave Macmillan.
- Jess; Mary Southcott (1998). Making Votes Count: The Case for Electoral Reform. London: Profile Books.
- John Hickman and Chris Little. "Seat/Vote Proportionality in Romanian and Spanish Parliamentary Elections" Journal of Southern Europe and the Balkans Vol. 2, No. 2, November 2000
- Roland Nicholson, Jr., "Proportional Representation Elections in Hong Kong", New York Times, September, 1992
See also 
- Apportionment (politics)
- D'Hondt method
- List of politics-related topics
- Sainte-Laguë method
- Hare quota
- Kolesar, Robert J. (1996-04-20). "Communism, Race, and the Defeat of Proportional Representation in Cold War America". Massachusetts: Mount Holyoke College. Retrieved 2010-05-12.
- McDonald, Dr. Michael. "United States Election Project > Voter Turnout". Fairfax, VA: George Mason University. Retrieved 2010-05-12.
- As counted from the table in http://www.wahlrecht.de/ausland/europa.htm [in German]; "Vorzugsstimme(n)" means "open list".
- Proportional Representation Irish citizens information
- New York Times, May 29, 1993, "Proportional Representation Suits School Elections" by Roland Nicholson, Jr.
- Proportional Representation Library
- "Proportional representation" Center for Voting and Democracy
- Handbook of Electoral System Choice
- "Electoral Systems", World Policy Institute
- Quantifying Representativity Article by Philip Kestelman
- The De Borda Institute A Northern Ireland-based organisation promoting inclusive voting procedures
- Electoral Reform Society founded in England in 1884, the longest running PR organization. Contains good information about Single Transferable Vote -the Society's preferred form of PR
- Electoral Reform Australia
- Proportional Representation Society of Australia
- Fair Vote Canada
- Why Not Proportional Representation?
- Vote Dilution means Voters have Less Voice Law is Cool site
- Proportional Representation and British Democracy Debate on British electoral system reform
- Felsenthal, Dan S. (2010). "Review of paradoxes afflicting various voting procedures where one out of m candidates (m ≥ 2) must be elected". Assessing Alternative Voting Procedures (London, UK: London School of Economics and Political Science). Retrieved October 9, 2011.