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Plurality Voting System

Electoral methods
This series is part of the
Politics and the Election series
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Enlarge picture
An example of a plurality ballot.
The plurality voting system is a single-winner voting system often used to elect executive officers or to elect members of a legislative assembly which is based on single-member constituencies.

The most common system, used in Canada, India, the UK, and the USA, is first past the post or winner-takes-all, a voting system in which a single winner is chosen in a given constituency by having the most votes.

In some countries such as France a similar system is used, but there are two rounds: the "two-round" or "two-ballot" plurality system. The two highest-voted candidates of the first round compete in a two-candidate second round or all candidates above a certain threshold in the first round compete in a two-, three- or four-candidate second round. If one candidate has a majority of votes in the first round, there is no second round.

In political science, the use of the plurality voting system alongside multiple, single-winner constituencies to elect a multi-member body is often referred to as single-member district plurality or SMDP.[1] Plurality voting is also variously referred to as winner-takes-all or relative/simple majority voting; however, these terms can also refer to elections for multiple winners in a particular constituency using bloc voting.

The famous works of Arend Lijphart use the term "majoritarian" systems, which is used almost synonymously with "plurality" systems.

First past the post

The term first past the post (abbreviated FPTP or FPP) was coined as an analogy to horse racing, where the winner of the race is the first to pass a particular point on the track (in this case a plurality of votes), after which all other runners automatically and completely lose (that is, the payoff is "winner-takes-all"). There is, however, no "post" that the winning candidate must pass in order to win, as they are only required to receive the largest number of votes in their favour. This sometimes results in the alternative name "furthest past the post".

Historically, FPTP has been a contentious electoral system, giving rise to the concept of electoral reform and a multiplicity of different voting systems intended to address perceived weaknesses of plurality voting.

Plurality voting is used in 43 of the 191 countries in the United Nations for either local or national elections. Plurality voting is particularly prevalent in the United Kingdom and former British colonies, including the United States and Canada. [2] See Westminster system.

Voting

In single winner plurality voting, each voter is allowed to vote for only one candidate, and the winner of the election is whichever candidate represents a plurality of voters, that is, whoever received the largest number of votes. This makes the plurality voting system among the simplest of all voting systems.

In an election for a legislative body, each voter in a given geographically-defined electoral district votes for one candidate from a list of candidates competing to represent that district. Under the plurality system, the winner of the election acts as representative of the entire electoral district, and serves with representatives of other electoral districts.

In an election for a single seat, such as president in a presidential system, the same style of ballot is used and the candidate who receives the largest number of votes represents the entire population (except in the United States, which uses the Electoral College).

Ballot types

Generally plurality ballots can be categorised into two forms. The simplest form is a blank ballot where the name of a candidate is written in by hand. A more structured ballot will list all the candidates and allow a mark to be made by a single candidate, however a structured ballot can also include space for a write-in candidate as well.

Plurality voting is based on minimal information — a person's vote can be entirely represented by a binary choice, so anything can be used to signify a vote — the ancient Greeks would vote on ostracising someone by scratching the name of the person to be ostracised on a piece of pottery. Votes cast as physical objects can also create a realistic display of the election results, such as an array of candidates with jars filled with differently coloured beans, with the winner being the most-filled.

Examples of plurality voting

Simple example

The election of a Member of Parliament in the UK is a well known example of the First Past the Post electoral system. But the system is also used on a smaller scale.
The election for class president
For this example, consider the election for the president of a school class. Each class has a president, who sits on a school council. Further assume that, in this imaginary school, male and female students disagree with each other on most issues, and students prefer to vote for others of the same sex as themselves.

In our hypothetical election, there are three candidates: Amy, Brian and Cathy. Each class member gets a ballot, with these three names on it. Each voter must put an "X" by one of the names on their ballot.

After the election finishes, the papers are sorted into three piles--one for votes for Amy, one for votes for Brian, and one for votes for Cathy.

The largest pile decides the winner. If Amy's pile has 11 votes, Brian's has 16, and Cathy's has 13, Brian wins.

Notice that there were a total of 40 votes cast, and the winner had only 16 of them — only 40%.

Note that the class members (the "electors") only vote once, and their votes help to choose both a class president and a member of the school council (the same person).
The election for school council
Suppose that all the other classes hold similar elections. Across all the classes, 8 of the class presidents that were elected were girls, and 9 were boys. That makes the boys the overall winner. The only influence that the pupils in this particular class had was to vote for Amy, Brian or Cathy to represent themselves.

Some might argue that a boy won for this class because there were two girls, who "split the vote": some of the girls in the class voted for Amy and others for Cathy. Perhaps if Amy had not been a candidate, all the girls would have voted for Cathy and she would have won this class; this in turn would make the girls the winners of the whole council. This is known as the spoiler effect.

More complex example

Enlarge picture
Tennesee's four cities are spread throughout the state
Imagine that the population of Tennessee, a state in the United States, is voting on the location of its capital. The population of Tennessee is concentrated around its four major cities, which are spread throughout the state. For this example, suppose that the entire electorate lives in these four cities, and that everyone wants to live as near the capital as possible. The candidates for the capital are: The preferences of the voters would be divided like this:
42% of voters
(close to Memphis)
26% of voters
(close to Nashville)
15% of voters
(close to Chattanooga)
17% of voters
(close to Knoxville)
  1. Memphis
  2. Nashville
  3. Chattanooga
  4. Knoxville
  1. Nashville
  2. Chattanooga
  3. Knoxville
  4. Memphis
  1. Chattanooga
  2. Knoxville
  3. Nashville
  4. Memphis
  1. Knoxville
  2. Chattanooga
  3. Nashville
  4. Memphis


Voting is accomplished whereby each voter in each city selects one city on the ballot (Memphis voters select Memphis, Nashville voters select Nashville, etc.) Votes are tabulated; Memphis is selected with the most votes (42%). Note that this system does not require that the winner have a majority, but only a plurality. Memphis wins because it has the most votes, even though 58% of the voters in this example preferred Memphis least.

Advantages

Plurality is often conflated with Single-winner voting systems in general, in order to contrast it with Proportional Representation. See the advantages there for other advantages of plurality in this context, such as regionalism and accountability.

Simplicity

Plurality may well be the simplest of all voting systems. This implies specific advantages. It is likely to be quicker, and easier to administer; this may also imply that an election costs less to run. It may also have an effect on voters, because it is easy to explain and understand. Alternative voting systems may alienate some voters who find the systems hard to understand, and who therefore feel detached from the direct effect of their own vote.

Preservation of One Person One Vote principle

The arguments for a plurality voting system rely heavily on the preservation of the "one person, one vote" principle (often shortened to OMOV for "one man, one vote" or more recently "one member, one vote"), as cited by the Supreme Court of the United States, wherein each voter is only able to cast one vote in a given election, where that vote can only go to one candidate. Plurality voting systems elect the candidate who is preferred first by the largest number of voters. Other voting systems, such as Instant-runoff voting or Single Transferable Vote also preserve OMOV, but rely on lower voter preference to arrive at a candidate earning either absolute majority or droop quota, respectively.

However, proponents of other systems, such as approval voting, point out that the OMOV principle was made to control the magnitude of districts; that each district must be relatively in proportion to one another in population. Approval voting does not actually represent some voters more than others, so the OMOV principle would be a weak one to discount it on. In any case, it could be argued approval voting grants one vote for each candidate to each voter - which they may choose not to cast, and cannot vote cumulate on one candidate.

Disadvantages

See single-winner voting systems for other disadvantages commonly associated with plurality, such as diminished representation, sweepout and other skewed results, and "safe seats".

Tactical voting

To a much greater extent than many other electoral methods, plurality electoral systems encourage tactical voting techniques, like "compromising". Voters are pressured to vote for one of the two candidates they predict are most likely to win, even if their true preference is neither, because a vote for any other candidate will be likely to be wasted and have no impact on the final result. This is known as Duverger's Law.

In the Tennessee example, if all the voters for Chattanooga and Knoxville had instead voted for Nashville, then Nashville would have won (with 58% of the vote); this would only have been the 3rd choice for those voters, but voting for their respective 1st choices (their own cities) actually results in their 4th choice (Memphis) being elected.

The difficulty is sometimes summed up, in an extreme form, as "All votes for anyone other than the second place are votes for the winner", because by voting for other candidates, they have denied those votes to the second place candidate who could have won had they received them. It is often claimed by United States Democrats that Democrat Al Gore lost the 2000 Presidential Election to Republican George W. Bush because some voters on the left voted for Ralph Nader of the Green Party, who presumably would have preferred Gore to Bush. Conversely, Republicans can claim that Ross Perot was a spoiler who enabled Bill Clinton to win the 1992 and 1996 presidential elections with a minority of the popular vote, because Perot had split the conservative vote, winning 8.4 percent of the vote, far better than Nader did, with less than 0.5 percent of the vote.

Such a mentality is reflected by elections in Puerto Rico and its three principal voter groups: the Independentistas (pro-independence), the Populares (pro-commonwealth), and the Estadistas (pro-statehood). Historically, there has been a tendency for Independentista voters to elect Popular candidates and policies. This phenomenon is responsible for some Popular victories, even though the Estadistas have the most voters on the island. It is so widely recognised that the Puertoricans sometimes call the Independentistas who vote for the Populares "melons", because the fruit is green on the outside but red on the inside (in reference to the party colours).

Because voters have to predict in advance who the top two candidates will be, this can cause significant perturbation to the system: A feature of the FPTP system is that invariably, voters can select only one candidate in a single-member district, whilst in multi-member districts they can never select more candidates than the number of seats in the district. Some argue that FPTP would work better if electors could cast votes for as many candidates as they wish. This would allow voters to "vote against" a certain despised candidate if they choose, without being forced to guess who they should vote for to defeat that candidate, thus eliminating the need for tactical voting. Such a system would also serve to reduce the spoiler effect. This system is called approval voting.

Effect on political parties

Duverger's law is a principle of political science which predicts that constituencies that use first-past-the-post systems will become two-party systems, given enough time.

First-past-the-post tends to reduce the number of political parties to a greater extent than most other methods, thus making it more likely that a single party will hold a majority of legislative seats. (In the United Kingdom, 18 out of 22 General Elections since 1922 have produced a majority government.) Single party rule enables quicker decision-making with less need for back and forth negotiation; some argue that this is an advantage.

Multi-party coalitions, on the other hand, require consent among all coalition partners to pass legislation, which some argue gives small parties a disproportionate amount of power. In the UK, arguments for plurality often look to Italy where the frequent government changeovers are presented as undesirable. (This problem could be solved with separation of powers, in which the entire government didn't have to turn over just because it lost a vote.)

FPTP's tendency toward fewer parties and more frequent one-party rule can also produce disadvantages. One such disadvantage is that the government may not consider as wide a range of perspectives and concerns. It is entirely possible that a voter will find that all major parties agree on a particular issue. In this case, the voter will not have any meaningful way of expressing a dissenting opinion through his or her vote.

Another disadvantage is that fewer choices are offered to the voters, often pressuring voters to vote for a candidate with whom they largely disagree so as to oppose a candidate with whom they disagree even more (See tactical voting above); this feature pressures candidates to appeal to the extremes in order to avoid being undercut. This appeal-to-extremes operates by giving those voters who are more centrist no choice but to vote for them. The likely result of this is that candidates will less closely reflect the viewpoints of those who vote for them.

It may also be argued that one-party rule is more likely to lead to radical changes in government policy that are only favoured by a plurality or bare majority of the voters, whereas multi-party systems usually require greater consensus in order to make dramatic changes.

Wasted votes

Wasted votes are votes cast for losing candidates or votes cast for winning candidates in excess of the number required for victory. For example, in the UK General Election of 2005, 52% of votes were cast for losing candidates and 18% were excess votes - a total of 70% wasted votes. This is perhaps the most fundamental criticism of FPTP, that a large majority of votes may play no part in determining the outcome. Alternative electoral systems attempt to ensure that almost all votes are effective in influencing the result and the number of wasted votes is consequently minimised.

Disproportionate influence of smaller parties

Smaller parties can disproportionately change the outcome of a FPTP election by swinging what is called the 50-50% balance of two party systems, by creating a faction within one or both ends of the political spectrum which shifts the winner of the election from an absolute majority outcome to a simple majority outcome favouring the previously less favoured party. In comparison, for electoral systems using proportional representation small groups win only their proportional share of representation. In the United States, this mechanism falls within one major reasoning (USA, Voting act, 1970s) favoring two-party, First-past-the-post (FPTP) electoral systems.

Current events

The United Kingdom continues to use the first-past-the-post electoral system for general elections, and for local government elections in England and Wales. Changes to the UK system have been proposed, and alternatives were examined by the Jenkins Commission in the late 1990s but no major changes have been implemented. Canada also uses this system for national and provincial elections. In May 2005 the Canadian province of British Columbia had a referendum on abolishing single-member district plurality in favour of multi-member districts with the Single Transferable Vote system after the Citizens' Assembly on Electoral Reform made a recommendation for the reform. The referendum obtained 57% of the vote, but failed to meet the 60% requirement for passing. An October 2007 referendum in the Canadian province of Ontario on adopting a Mixed Member Proportional system, also requiring 60% approval, failed with only 36.9% voting in favour.

Wales, Scotland, Northern Ireland, the Republic of Ireland and Australia are notable examples of countries within the UK, or with previous links to it, that use non-FPTP electoral systems.

Recent examples of nations which have undergone democratic reforms but have not adopted the FPTP system include South Africa, almost all of the former Eastern bloc nations, Russia, Afghanistan and Iraq.

Where plurality voting is used

Countries that use this system to elect the lower or only house of their legislature include:
See also: Table of voting systems by nation


The plurality election system is used in the Republic of China on Taiwan for executive offices such as county magistrates, mayors, and the president, but not for legislative seats which used the single non-transferable vote system. This has produced an interesting party structure in which there are two broad coalitions of parties which cooperate in executive elections but which compete internally in legislative elections. [3]

India uses a proportional representation system for its upper house.

See also

References

1. ^ "Plurality-Majority Systems"
2. ^ "The Global Distribution of Electoral Systems"
3. ^ Making Votes Count, Gary Cox (1997)

External links

Voting
Part of a series of articles
on Politics and Elections


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Politics is the process by which groups of people make decisions. Although the term is generally applied to behavior within civil governments, politics is observed in all human group interactions, including corporate, academic, and religious
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An election is a decision making process where people choose people to hold official offices. This is the usual mechanism by which modern democracy fills offices in the legislature, sometimes in the executive and judiciary, and for regional and local government.
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Preferential voting (or preference voting) is a type of ballot structure used in several electoral systems in which voters rank a list or group of candidates in order of preference.
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A Condorcet method is a single winner election method in which voters rank candidates in order of preference. There are multiple slightly differing methods—including the Kemeny-Young method, Ranked Pairs, and the Schulze method—that satisfy the definition to be
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Copeland's method is a Condorcet method in which the winner is determined by finding the candidate with the most pairwise victories.

Proponents argue that this method is easily understandable to the general populace, which is generally familiar with the sporting
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The Kemeny-Young method is a voting system that uses preferential ballots, pairwise comparison counts, and sequence scores to identify the most popular choice, and also identify the second-most popular choice, the third-most popular choice, and so on down to the
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Nanson method and Baldwin method.

Nanson method

The Nanson method is based on the original work of the mathematician Edward J. Nanson.

Nanson's method
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Ranked Pairs (RP) or Tideman (named after its developer Nicolaus Tideman) is a voting method that selects a single winner using votes that express preferences. RP can also be used to create a sorted list of winners.
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two-round system (also known as the second ballot or runoff voting) is a voting system used to elect a single winner. Under runoff voting, the voter simply casts a single vote for their favourite candidate.
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Instant-runoff voting (IRV) is a voting system used for single-winner elections in which voters have one vote, but can rank candidates in order of preference. In an IRV election, if no candidate receives a majority of first choices, the candidate with the fewest number of
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The Coombs' method, created by Clyde Coombs, is a voting system used for single-winner elections in which each voter rank-orders the candidates. It is very similar to Instant Runoff Voting (also known as 'Preferential Voting' or the Alternative Vote).
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The Schulze method is a voting system developed in 1997 by Markus Schulze that selects a single winner using votes that express preferences. The method can also be used to create a sorted list of winners.
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Approval voting is a voting system used for elections, in which each voter can vote for as many or as few candidates as desired. It is typically used for single-winner elections.
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Range voting (also called ratings summation, average voting, cardinal ratings, 0–99 voting, or the score system or point system
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Proportional representation (sometimes referred to as full representation, or PR), is a category of electoral formula aiming at a close match between the percentage of votes that groups of candidates (grouped by a certain measure) obtain in elections and the percentage of seats
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Mixed member proportional representation, also termed mixed-member proportional voting and commonly abbreviated to MMP, is a voting system used to elect representatives to numerous legislatures around the world.
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Party-list proportional representation systems are a family of voting systems used in multiple-winner elections (e.g. elections to parliament), emphasizing proportional representation (PR). They can also be used as part of mixed additional member systems.
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The D'Hondt method (equivalent to Jefferson's method, and Budder-Ofer method) is a highest averages method for allocating seats in party-list proportional representation. The method is named after Belgian mathematician Victor D'Hondt.
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The highest averages method is one way of allocating seats proportionally for representative assemblies with party list voting systems.

The highest averages method
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The largest remainder method is one way of allocating seats proportionally for representative assemblies with party list voting systems. It is a contrast to the highest averages method.
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Single transferable vote (STV) is a preferential voting system designed to minimize wasted votes and provide proportional representation while ensuring that votes are explicitly for candidates rather than party lists.
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Cumulative voting (also accumulation voting or weighted voting) is a multiple-winner voting system intended to promote proportional representation while also being simple to understand.
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Parallel voting describes a mixed voting system where voters in effect participate in two separate elections using different systems, and where the results in one election have little or no impact on the results of the other.
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The single non-transferable vote or SNTV is an electoral system used in multi-member constituency elections.

Voting

In any election, each voter casts one vote for one candidate in a multi-candidate race for multiple offices.
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Cumulative voting (also accumulation voting or weighted voting) is a multiple-winner voting system intended to promote proportional representation while also being simple to understand.
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Bloc voting (or block voting) refers to a class of voting systems which can be used to elect several representatives from a single multimember constituency. There are several variations of bloc voting depending on the ballot type used; however, they all produce similar
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Limited voting is a voting system in which electors have fewer votes than there are positions available. The positions are awarded to the candidates who receive the most votes absolutely.
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Demarchy is a term that describes a political system based on randomly selected groups of decision makers, also known as sortition. Demarchy attempts to achieve democratic representation without needing elections—it has been referred to as "democracy without elections.
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Sortition (also known as allotment) is a fair method of selection by some form of lottery such as drawing coloured pebbles from a bag. It is used particularly to allot decision makers.
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