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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. This voting method is also used in multi-member constituencies in what is referred to as an exhaustive counting system where one member is elected at a time and the process repeated until the number of vacancies is filled.
The most common system, used in Canada, India, the United Kingdom, and the United States, is simple plurality, first past the post or winner-takes-all. In this voting system the single winner is the person with the most votes; there is no requirement that the winner gain an absolute majority of votes.
In some countries such as France (as well as in some jurisdictions of the United States, such as Louisiana and Georgia) a similar system is used, but there are two rounds: the "two-ballot" or "runoff election" plurality system. If any candidate in the first round gains a majority of votes, then there is no second round; otherwise, 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.
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. 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.
Confusion in terminology is often used between Highest vote, Majority vote and Plurality voting.
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".
In a multiple member first-past-the-post ballots the first candidates in order of highest vote to cross the line are elected. In some cases the system involves a iteration of the counting of Plurality votes.
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 for local and/or national elections in 43 of the 191 countries of the United Nations, as well as in the Republic of China (Taiwan). Plurality voting is particularly prevalent in the United Kingdom and former British colonies, including the United States, Canada and India. See Westminster system.
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 for voters and vote counting officials (it is however very contentious to draw district boundary lines in this system).
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. (The President of the United States is indirectly elected by such a rule; but see Electoral College.)
The two-round voting system uses first-past-the-post voting method in the first round of voting. In this case the two highest polling candidates that cross the line progress to the second round Run-off ballot.
In a multiple member Plurality election the counting of the ballot uses an exhaustive iteration process using the same ballot papers to elect one person each iteration for each vacant position.
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.
The United Kingdom is usually described as a two-party system, but some third parties are important. The UK, like many democracies, is more accurately a "two-plus" party system. In 1979, for example, the withdrawal of support by the eleven Scottish Nationalists in Commons brought down the Callaghan government in a rare vote of no confidence. The Liberal Democrats may get one vote in five, forcing the Labour and Conservative parties to change positions on some issues.
The United Kingdom, like the United States and Canada, uses single-member districts as the base for elections. This old English system is simple: Each electoral district or constituency sends one person to the legislature, the candidate that gets the most votes even if less than a majority, sometimes called "first past the post" (FPTP). In 1992, for example, a Liberal Democrat in Scotland won with just 26 percent of the vote. This system of single-member districts with plurality victors tends to produce two large political parties. The reason: there is a big premium to combine small parties into big ones in order to edge out competitors. If one of the two large parties splits, which sometimes happens, the election is thrown to the other party, the one that hangs together. In countries with proportional representation there is not such a great premium on forming two large parties, and that contributes to multi-party systems.
Scotland and Northern Ireland both use the first past the post system for general elections in the UK, but use versions of proportional representation for local elections and European elections.
The countries that inherited the British majoritarian system tend toward two large parties, one left, the other right, such as the U.S. Democrats and Republicans. Canada is an exception to this pattern, because its third parties are territorially concentrated, especially the separatist Bloc Québécois. New Zealand used the British system, and it too yielded two large parties. It also left many New Zealanders discontent, because other viewpoints got ignored, so its parliament in 1993 adopted a new electoral law, modeled on Germany's system of PR with a partial selection by constituencies. New Zealand soon developed a more complex party system.
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.
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).
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.
Imagine that Tennessee is having an election 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)
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. Notice that this problem does not hold anymore in the two-round system.
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 constituency link, regionalism, and accountability.
The arguments for a plurality voting system rely 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, although this need not be an absolute majority. Other voting systems, such as instant-runoff voting, party-list proportional representation or single transferable vote also preserve OMOV, but rely on lower voter preference to enable a candidate to earn either an absolute majority (single member district) or a quota (multi-member district), respectively.
However, OMOV principle was made to control the magnitude of districts; that each district must be of the same order of magnitude in size, malapportionment, the term for having unequally sized electoral districts, violates the one person, one vote rule. For example a Senator from California represents 36,961,664, whereas a Senator from Wyoming represents 544,270, each Wyoming vote therefore has a 68 times greater say in the Senate than does each California vote.
Some other voting systems can end giving a higher chance of victory to a candidate perceived as having extreme views. Under a first-past-the-post system, voters are often afraid of "wasting" their vote on a candidate unlikely to win, so they cast their vote towards their most preferable choice possible of victory. Advocates of plurality voting suggest that this results in most candidates having to field a fairly moderate or centrist position. This is debated by advocates of other systems, who argue that preferential voting or range voting systems, by getting more information from voters, allow a more rigorous definition of the word "moderate" and can be designed to explicitly favor candidates fitting that description.
Plurality voting tends to promote two-party systems (even more so than other single-winner systems). Supporters view this as beneficial, as parliamentary governments, or other coalitions, are typically more stable in two-party systems, and thus small minorities are not given undue voice. First-past-the-post minimizes the influence of third parties and thus arguably keeps out extremists. However, this can also deny fair representation to positive third parties, racial minorities, women, and others.
As any majoritarian system, it ensures strong government.
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 likely be wasted and have no impact on the final result.
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 exit polls indicated would have preferred Gore to Bush 45 percent to 27 percent, with the rest not voting in Nader's absence.
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 colors).
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. Proponents of approval voting systems 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 reducing the need for tactical voting. Such a system would also serve to reduce the spoiler effect.
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 single party majority government.)
FPTP's tendency toward fewer parties and more frequent one-party rule can also produce a government that 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.
As fewer choices are offered to the voters, voters may 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). The downside 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 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.
Because FPTP permits a high level of wasted vote, an election under FPTP is easily gerrymandered. Through gerrymandering, constituencies are deliberately designed to unfairly increase the number of seats won by one party at the expense of another.
In brief, suppose that governing party G wishes to reduce the seats that will be won by opposition party O in the next election. It creates a number of constituencies in each of which O has an overwhelming majority of votes. O will win these seats, but a large number of its voters will waste their votes. Then the rest of the constituencies are designed with small majorities for G. Few G votes are wasted, and G will win a large number of seats by small margins. As a result of the gerrymander, O's seats have cost it more votes than G's seats.
The presence of spoilers often gives rise to suspicions that manipulation of the slate has taken place. The spoiler may have received incentives to run. A spoiler may also drop out at the last moment, inducing charges that such an act was intended from the beginning.
Smaller parties can disproportionately change the outcome of an 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. However in PR systems, small parties can become decisive in Parliament so gaining a power of blackmail against the Government, a problem which is generally reduced by the FPTP system.
See single-winner voting systems for other disadvantages commonly associated with plurality, such as diminished representation, sweepout and other skewed results, and "safe seats".
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. On 9 February 2010 the UK Parliament voted in favour of a referendum on the possible use of the Alternative vote system 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.
Northern Ireland, Scotland, Wales, the Republic of Ireland, Australia and New Zealand are notable examples of countries within the UK, or with previous links to it, that use non-FPTP electoral systems (Northern Ireland, Scotland and Wales use First Past the Post in general elections, however).
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.
Countries that use this system to elect the lower or only house of their legislature include:
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.