Two-round system
Encyclopedia
The two-round system is a voting system
Voting system
A voting system or electoral system is a method by which voters make a choice between options, often in an election or on a policy referendum....
used to elect a single winner where the voter casts a single vote for their chosen candidate. However, if no candidate receives the required number of votes (usually the absolute majority or 40-45% with a winning margin of 5-15%), then those candidates having less than a certain proportion of the votes, or all but the two candidates receiving the most votes, are eliminated, and a second round of voting occurs.
The two round system is used around the world for the election of legislative bodies and directly elected presidents. For example, it is used in French presidential, legislative, and cantonal elections
Elections in France
France is a representative democracy. Public officials in the legislative and executive branches are either elected by the citizens or appointed by elected officials...
, and also to elect the presidents of Afghanistan
President of Afghanistan
Afghanistan has only been a republic between 1973 and 1992 and from 2001 onwards. Before 1973, it was a monarchy that was governed by a variety of kings, emirs or shahs...
, Argentina
President of Argentina
The President of the Argentine Nation , usually known as the President of Argentina, is the head of state of Argentina. Under the national Constitution, the President is also the chief executive of the federal government and Commander-in-Chief of the armed forces.Through Argentine history, the...
, Austria
President of Austria
The President of Austria is the federal head of state of Austria. Though theoretically entrusted with great power by the constitution, in practice the President acts, for the most part, merely as a ceremonial figurehead...
, Brazil
President of Brazil
The president of Brazil is both the head of state and head of government of the Federative Republic of Brazil. The president leads the executive branch of the federal government and is the commander-in-chief of the Brazilian Armed Forces...
, Bulgaria, Chile
President of Chile
The President of the Republic of Chile is both the head of state and the head of government of the Republic of Chile. The President is responsible of the government and state administration...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Croatia
President of Croatia
The President of Croatia , officially styled the President of the Republic represents the Republic of Croatia in the country and abroad as the head of state, maintains the regular and coordinated operation and stability of the national government system, and safeguards the independence and...
, Cyprus, Dominican Republic, Finland
President of Finland
The President of the Republic of Finland is the nation's head of state. Under the Finnish constitution, executive power is vested in the President and the government, with the President possessing extensive powers. The President is elected directly by the people of Finland for a term of six years....
, Ghana
President of Ghana
The President of Ghana is the elected head of state and head of government of Ghana. Officially styled President of the Republic of Ghana and Commander-in-Chief of the Ghanaian Armed Forces. The current President of Ghana is Prof. John Atta Mills, who took office in January...
, Guatemala
President of Guatemala
The title of President of Guatemala has been the usual title of the leader of Guatemala since 1839, when that title was assumed by Mariano Rivera Paz...
, Indonesia
President of Indonesia
The President of the Republic of Indonesia is the head of state and the head of government of the Republic of Indonesia.The first president was Sukarno and the current president is Susilo Bambang Yudhoyono.- Sukarno era :...
, Poland, Portugal
President of Portugal
Portugal has been a republic since 1910, and since that time the head of state has been the president, whose official title is President of the Portuguese Republic ....
, Romania
President of Romania
The President of Romania is the head of state of Romania. The President is directly elected by a two-round system for a five-year term . An individual may serve two terms...
, Serbia
President of Serbia
The President of Serbia is the head of state of Serbia. Presently serving as the head of state is Boris Tadić. He was elected with a narrow majority of 50.31% in the 2008 Serbian presidential elections.-Authority, legal and constitutional rights:...
, Slovakia
President of Slovakia
The President of Slovakia is the head of state of Slovakia. The President is directly elected by the people for five years, and can be elected for a maximum of two consecutive terms. The presidency is largely a ceremonial office, but the President does exercise certain limited powers with absolute...
, Slovenia
President of Slovenia
The function of President of the Republic of Slovenia was established on 23 December 1991, when the National Assembly of Slovenia passed a new constitution as a result of independence from Socialist Federal Republic of Yugoslavia....
, Ukraine
President of Ukraine
Prior to the formation of the modern Ukrainian presidency, the previous Ukrainian head of state office was officially established in exile by Andriy Livytskyi. At first the de facto leader of nation was the president of the Central Rada at early years of the Ukrainian People's Republic, while the...
, Uruguay
President of Uruguay
The President of the Oriental Republic of Uruguay is the head of state of Uruguay. His or her rights are determined in the Constitution of Uruguay. Conforms with the Secretariat of the Presidency, the Council of Ministers and the Director of the Office of Planning and Budget, the executive branch...
, Zimbabwe —see: Table of voting systems by nation
Table of voting systems by nation
This table deals with voting to select candidates for office, not for the passing of legislation.- Voting systems by country :- Key :Seats per district : Most elections are split into a number of electoral districts. In some elections, there is one person elected per district. In others, there are...
. Historically it was used in the German Empire
German Empire
The German Empire refers to Germany during the "Second Reich" period from the unification of Germany and proclamation of Wilhelm I as German Emperor on 18 January 1871, to 1918, when it became a federal republic after defeat in World War I and the abdication of the Emperor, Wilhelm II.The German...
of 1871-1918, and in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
in the 1908
New Zealand general election, 1908
The New Zealand general election of 1908 was held on Tuesday, 17 November, 24 November and 1 December in the general electorates, and on Wednesday, 2 December in the Māori electorates to elect a total of 80 MPs to the 17th session of the New Zealand Parliament...
and 1911
New Zealand general election, 1911
The New Zealand general election of 1911 was held on Thursday, 7 and 14 December in the general electorates, and on Tuesday, 19 December in the Māori electorates to elect a total of 80 MPs to the 18th session of the New Zealand Parliament...
elections.
Terminology
The two-round system is known as runoff voting in the United States, where the second round is known as a runoff election. Runoff voting is also sometimes used as a generic term to describe any system involving a number of rounds of voting, with eliminations after each round. By this broader definition the two-round system is not the only form of runoff voting, and others include the exhaustive ballotExhaustive ballot
The exhaustive ballot is a voting system used to elect a single winner. Under the exhaustive ballot the elector simply casts a single vote for his or her favorite candidate. However if no candidate is supported by an overall majority of votes then the candidate with the fewest votes is eliminated...
and instant run-off voting (also known as the alternative vote). However the subject of this article is the two round system.
In Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, for example, candidates for party leadership, when there are more than two, use an exhaustive ballot system, often called a runoff voting system. It is like a runoff system, except the one candidate must win a simple majority (over half). Candidates with the fewest votes or candidates who want to move their support to other candidates may also move to remove themselves from the next vote.
Voting and counting
In both rounds of an election conducted using runoff voting, the voter simply marks an "X" beside his/her favorite candidate. If no candidate has an absolute majority of votes (i.e. more than half) in the first round, then the two candidates with the most votes proceed to a second round, from which all others are excluded. In the second round, because there are only two candidates, one candidate will achieve an absolute majority. In the second round each voter is entirely free to change the candidate he votes for, even if his preferred candidate has not yet been eliminated but he has merely changed his mind.Some variants of the two round system use a different rule for choosing candidates for the second round, and allow more than two candidates to proceed to the second round. Under these systems it is sufficient for a candidate to receive a plurality of votes (i.e. more votes than anyone else) to be elected in the second round. In elections for the French National Assembly any candidate with fewer than 12.5% of the total vote is eliminated in the first round, and all remaining candidates are permitted to stand in the second round, in which a plurality is sufficient to be elected. Under some variants of runoff voting there is no formal rule for eliminating candidates, but, rather, candidates who receive few votes in the first round are expected to withdraw voluntarily. Historically, the President of Weimar Germany
Reichspräsident
The Reichspräsident was the German head of state under the Weimar constitution, which was officially in force from 1919 to 1945. In English he was usually simply referred to as the President of Germany...
was popularly elected in 1925
German presidential election, 1925
The presidential election of 1925 was the first direct election to the office of President of the Reich , Germany's head of state during the 1919-1933 Weimar Republic. The first President, Friedrich Ebert, died on 28 February, 1925...
and 1932
German presidential election, 1932
The presidential election of 1932 was the second and final direct election to the office of President of the Reich , Germany's head of state during the 1919-1934 Weimar Republic. The incumbent President, Paul von Hindenburg, had been elected in 1925 but his seven year term expired in May...
by a two-round system that in the second round allowed any candidate to run and did not require an absolute majority. In both elections the Communist candidate Ernst Thälmann
Ernst Thälmann
Ernst Thälmann was the leader of the Communist Party of Germany during much of the Weimar Republic. He was arrested by the Gestapo in 1933 and held in solitary confinement for eleven years, before being shot in Buchenwald on Adolf Hitler's orders in 1944...
did not withdraw and ran in the second round; in 1925 this probably ensured the election of Paul von Hindenburg
Paul von Hindenburg
Paul Ludwig Hans Anton von Beneckendorff und von Hindenburg , known universally as Paul von Hindenburg was a Prussian-German field marshal, statesman, and politician, and served as the second President of Germany from 1925 to 1934....
(with only 48.3% of the vote) rather that Wilhelm Marx
Wilhelm Marx
Wilhelm Marx was a German lawyer, Catholic politician and a member of the Centre Party. He was Chancellor of the German Reich twice, from 1923 to 1925 and again from 1926 to 1928, and also served briefly as minister president of Prussia in 1925, during the Weimar Republic.-Life:Born in Cologne to...
the candidate of the centre parties.
Example I
Imagine an election to choose which food to eat for dessert. There are 25 people having dessert and four candidates: Ice Cream, Apple Pie, Fruit and Celery. Runoff voting is used to find the winner.Round 1: In the first round of voting each diner votes for the one candidate they most prefer. The results are as follows:
- Ice Cream: 10 votes
- Apple Pie: 6 votes
- Fruit: 8 votes
- Celery: 1 vote
Round 2: No candidate has an absolute majority of votes (in this election that would be 13) so the two candidates with the most votes, Ice Cream and Fruit, proceed to a second round, while Apple Pie and Celery are eliminated. Because their favorite candidates have been eliminated Apple Pie and Celery supporters must now vote for one of the two remaining candidates. The sole Celery supporter is health conscious, so now gives his vote to Fruit. However Apple Pie supporters are split: 3 prefer Ice Cream and 3 vote for Fruit. Of those who supported Ice Cream and Fruit in the first round no-one decides to change their vote. The results of the second round are therefore:
- Ice Cream: 13
- Fruit: 12
Result: Ice Cream now has an absolute majority so is declared the winner.
Example II
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
, a state in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, 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 they would all like the capital to be established as close to their own city as possible.
The candidates for the capital are:
- Memphis, the state's largest city, with 42% of the voters, but located far from the other cities
- Nashville, with 26% of the voters
- Knoxville, with 17% of the voters
- Chattanooga, with 15% of the voters
Round 1: In the first round of voting the results will be as follows:
- Memphis: 42%
- Nashville: 26%
- Knoxville: 17%
- Chattanooga: 15%
Round 2: No candidate has an absolute majority in the first round (this would be greater than 50%), so Memphis and Nashville proceed to the next round, while Knoxville and Chattanooga are excluded. Both eliminated cities are closer to Nashville than they are to Memphis. Therefore all of those who vote for either of the eliminated cities chose to vote for Nashville in the second round. None of the Memphis or Nashville supporters change their votes. The results are therefore:
- Nashville: 58%
- Memphis: 42%
Result: After round two Nashville has an absolute majority and is the winner.
French presidential election, 2002
Unlike the two examples above, this is from real life. In the 2002 French presidential electionFrench presidential election, 2002
The 2002 French presidential election consisted of a first round election on 21 April 2002, and a runoff election between the top two candidates on 5 May 2002. This presidential contest attracted a greater than usual amount of international attention because of Le Pen's unexpected appearance in...
, the two contenders described by the media as having the possibility to win were Jacques Chirac
Jacques Chirac
Jacques René Chirac is a French politician who served as President of France from 1995 to 2007. He previously served as Prime Minister of France from 1974 to 1976 and from 1986 to 1988 , and as Mayor of Paris from 1977 to 1995.After completing his studies of the DEA's degree at the...
and Lionel Jospin
Lionel Jospin
Lionel Jospin is a French politician, who served as Prime Minister of France from 1997 to 2002.Jospin was the Socialist Party candidate for President of France in the elections of 1995 and 2002. He was narrowly defeated in the final runoff election by Jacques Chirac in 1995...
, who represented the largest two political parties in France at the time. However, a third contender, Jean-Marie Le Pen
Jean-Marie Le Pen
Jean-Marie Le Pen is a French far right-wing and nationalist politician who is founder and former president of the Front National party. Le Pen has run for the French presidency five times, most notably in 2002, when in a surprise upset he came second, polling more votes in the first round than...
, unexpectedly obtained slightly more than Jospin in the first round of elections:
- Jacques Chirac 19.88%
- Jean-Marie Le Pen 16.86%
- Lionel Jospin 16.18%
Since no candidate obtained an absolute majority, a second round is organized with the first two candidates from the first. Jean-Marie Le Pen, however, was widely recognized as a controversial far right-wing candidate, and in the second round a vast majority of the voters rejected him:
- Jacques Chirac 82.21%
- Jean-Marie Le Pen 17.79%
This example demonstrates how the first two candidates from the first round might not necessarily be those expected to be the most popular by virtue of their party affiliations.
Exhaustive ballot
The exhaustive ballotExhaustive ballot
The exhaustive ballot is a voting system used to elect a single winner. Under the exhaustive ballot the elector simply casts a single vote for his or her favorite candidate. However if no candidate is supported by an overall majority of votes then the candidate with the fewest votes is eliminated...
(EB) is similar to the two round system, but involves more rounds of voting rather than just two. If no candidate receives an absolute majority in the first round then the candidate(s) with the fewest number of votes is eliminated and excluded from further ballots. The process of exclusion and reballot continues until one candidate has an absolute majority. Because voters may have to cast votes several times, EB is not used in large-scale public elections. Instead it is used in smaller contests such as the election of the presiding officer of an assembly; one long-standing example of its use is in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, where local associations (LCAs) of the Conservative Party
Conservative Party (UK)
The Conservative Party, formally the Conservative and Unionist Party, is a centre-right political party in the United Kingdom that adheres to the philosophies of conservatism and British unionism. It is the largest political party in the UK, and is currently the largest single party in the House...
use EB to elect their prospective parliamentary candidates (PPCs). EB often elects a different winner from runoff voting. Because the two round system excludes more than one candidate after the first round, it is possible for a candidate to be eliminated who would have gone on to win the election under EB.
http://soglasovanie66.ru/
Instant-runoff voting
Instant-runoff votingInstant-runoff voting
Instant-runoff voting , also known as preferential voting, the alternative vote and ranked choice voting, is a voting system used to elect one winner. Voters rank candidates in order of preference, and their ballots are counted as one vote for their first choice candidate. If a candidate secures a...
(IRV), like the exhaustive ballot, involves multiple reiterative counts in which the candidate with fewest votes is eliminated each time. Whilst the exhaustive ballot and the two round system both involve voters casting a separate vote in each round, under instant-runoff voters vote only once. This is possible because, rather than voting for only a single candidate, the voter ranks all of the candidates in order of preference. These preferences are then used to "transfer" the votes of those whose first preference has been eliminated during the course of the count. Because the two round system and the exhaustive ballot involve separate rounds of voting, voters can use the results of one round to decide how they will vote in the next, whereas this is not possible under IRV. Because it is necessary to only vote once, IRV, like the two round system, is used for large-scale elections in many places. IRV often elects a different winner to the two round system and tends to produce the same results as the exhaustive ballot.
Variants of Instant Runoff voting can be designed to reflect the same rules as a two-round voting system. If no single candidate has an absolute majority of votes then only the two highest polling candidates progress to the second count all other candidates are excluded and their votes redistributed according to the recorded preferences for continuing candidates. One variant that works this way is called the Contingent vote, detailed below.
IRV is known by different names in different countries. In Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
- where it is used to elect members of, among other institutions, its lower house - it is called Preferential voting
Preferential voting
Preferential voting is a type of ballot structure used in several electoral systems in which voters rank candidates in order of relative preference. For example, the voter may select their first choice as '1', their second preference a '2', and so on...
; in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and the Republic of Ireland
Republic of Ireland
Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...
- where it is used to elect the president - it is known as the Alternative Vote, or AV.
Contingent vote
The Contingent voteContingent vote
The contingent vote is an electoral system used to elect a single winner, in which the voter ranks the candidates in order of preference. In an election, if no candidate receives an absolute majority of first preference votes, then all but the two leading candidates are eliminated and there is a...
is a variant of instant-runoff voting that has been used in the past in Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. A criticism of this method is that "it requires two polls, and gives opportunity for intrigue of various kinds." Under the contingent vote voters cast only one vote, by ranking all of the candidates in order of preference. However it involves only two rounds of counting and uses the same rule for eliminating candidates as the two round system. After the first round all but the two candidates with most votes are eliminated. Therefore one candidate always achieves an absolute majority in the second round. Because of these similarities the contingent vote tends to elect the same winner as the two round system, and often produces different results to instant-runoff voting. A variant of the contingent vote, called the supplementary vote, is used to elect some mayors in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. Another variant elects the President of Sri Lanka
President of Sri Lanka
The President of Democratic Socialist Republic of Sri Lanka is the elected head of state and the head of government. The President is a dominant political figure in Sri Lanka. The office was created in 1978 but has grown so powerful there have been calls to restrict or even eliminate its power...
.
Nonpartisan blanket primary
In the United States, the nonpartisan blanket primary, introduced in LouisianaLouisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
for partisan state elections in 1975 and federal elections in 1978 (with a short return to a closed primary system in 2010), is virtually identical to the two-round system. Taking the standard American system of primary election
Primary election
A primary election is an election in which party members or voters select candidates for a subsequent election. Primary elections are one means by which a political party nominates candidates for the next general election....
s to choose each party's candidate followed by a general election wherein the winners of the primaries face off, the primary is "opened" to all voters to vote for whichever candidate they choose for each office, regardless of party affiliation. The two highest vote-winners in the "primary"—in effect the first round of a two-round system—are then the only candidates whose names would appear on the ballot at the general election, effectively requiring one candidate to win an absolute majority to take the office. The state of Washington, adopted a virtually identical system to Louisiana's in 2008, which came into effect after legal difficulties in 2010
United States elections, 2010
The 2010 United States elections were held on Tuesday, November 2, 2010. During this midterm election year, all 435 seats in the United States House of Representatives and 37 of the 100 seats in the United States Senate were contested in this election along with 38 state and territorial...
; California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
approved a similar system in 2010
California Proposition 14 (2010)
Proposition 14 is a California ballot proposition that appeared on the ballot during the June, 2010 state elections. It is a constitutional amendment that changed California's election processes by consolidating all primary elections for a particular office into an election with one ballot that...
, coming into effect for major state and federal elections in the elections of 2012
United States elections, 2012
The 2012 United States elections will be held on Tuesday, November 6, 2012. The 57th quadrennial presidential election will be held on this date, coinciding with Senate elections where 33 races will occur, as well as House of Representatives elections to elect the members for the 113th Congress...
.
The main difference between a nonpartisan blanket primary and a standard two-round system is that, depending on the structure of the law, it may not be possible to avoid a second round, even if one candidate wins an absolute majority of votes in the first round (the primary). However, it is not necessarily the case that a second round is always required; a more standard two-round system can also be implemented if that be the wish of the state legislature or the will of the people (expressed through initiative
Initiative
In political science, an initiative is a means by which a petition signed by a certain minimum number of registered voters can force a public vote...
or referendum
Referendum
A referendum is a direct vote in which an entire electorate is asked to either accept or reject a particular proposal. This may result in the adoption of a new constitution, a constitutional amendment, a law, the recall of an elected official or simply a specific government policy. It is a form of...
).
Compliance with voting system criteria
Most of the mathematical criteria by which voting systems are compared were formulated for voters with ordinal preferences. Some methods, like Approval votingApproval voting
Approval voting is a single-winner voting system used for elections. Each voter may vote for as many of the candidates as the voter wishes. The winner is the candidate receiving the most votes. Each voter may vote for any combination of candidates and may give each candidate at most one vote.The...
, requests information than can't be unambiguously inferred from a single set of ordinal preferences. The two-round system is such a method, because the voters are not forced to vote according to a single ordinal preference in both rounds.
Since the two-round system requires more information from each voter than a single ordinal ballot provides, one can't fit the criteria that are formulated expressly for voters with ordinal preferences without making a generalization as to how the voters will behave. The same problem exists in Approval voting, where one has to make assumptions as to how the voters will place their approval cutoffs.
If the voters determine their preferences before the election and always vote directly consistent to them, they will emulate the Contingent vote
Contingent vote
The contingent vote is an electoral system used to elect a single winner, in which the voter ranks the candidates in order of preference. In an election, if no candidate receives an absolute majority of first preference votes, then all but the two leading candidates are eliminated and there is a...
and get the same results as if they were to use that system. Therefore, in that model of voting behavior, the two-round system passes all criteria that the contingent vote passes, and fails all criteria the contingent vote fails.
Since the voters in the two-round system don't have to choose their second round votes while voting in the first round, they are able to adjust their votes as players in a game
Game theory
Game theory is a mathematical method for analyzing calculated circumstances, such as in games, where a person’s success is based upon the choices of others...
. More complex models consider voter behavior when the voters reach a game-theoretical equilibrium from which they have no incentive, as defined by their internal preferences, to further change their behavior. However, because these equilibria are complex, only partial results are known. With respect to the voters' internal preferences, the two-round system passes the majority criterion in this model, as a majority can always coordinate to elect their preferred candidate. Also, in the case of three candidates or less and a robust political equilibrium, the two-round system will pick the Condorcet winner whenever there is one, which is not the case in the Contingent vote model.
The equilibrium mentioned above is a perfect-information equilibrium and so only strictly holds in idealized conditions where every voter knows every other voter's preference. Thus it provides an upper bound on what can be achieved with rational (self-interested) coordination or knowledge of others' preferences. Since the voters almost surely won't have perfect information, it may not apply to real elections. In that matter, it is similar to the perfect competition
Perfect competition
In economic theory, perfect competition describes markets such that no participants are large enough to have the market power to set the price of a homogeneous product. Because the conditions for perfect competition are strict, there are few if any perfectly competitive markets...
model sometimes used in economics. To the extent that real elections approach this upper bound, large elections would do so less so than small ones, because it's less likely that a large electorate has information about all the other voters than that a small electorate has.
Tactical voting and strategic nomination
Runoff voting is intended to reduce the potential for eliminating "wasted" votes by tactical votingTactical voting
In voting systems, tactical voting occurs, in elections with more than two viable candidates, when a voter supports a candidate other than his or her sincere preference in order to prevent an undesirable outcome.It has been shown by the Gibbard-Satterthwaite theorem that any voting method which is...
. Under the "first past the post
Plurality voting system
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...
" (plurality) system voters are encouraged
Vote splitting
Vote splitting is an electoral effect in which the distribution of votes among multiple similar candidates reduces the chance of winning for any of the similar candidates, and increases the chance of winning for a dissimilar candidate....
to vote tactically by voting for only one of the two leading candidates, because a vote for any other candidate will not affect the result. Under runoff voting this tactic, known as "compromising", is sometimes unnecessary because, even if a voter's favourite candidate is eliminated in the first round, they will still have an opportunity to influence the result of the election by voting for a more popular candidate in the second round. However the tactic of compromising can still be used in runoff voting because it is sometimes necessary to compromise as a way of influencing which two candidates will survive to the second round. In order to do this it is necessary to vote for one of the three leading candidates in the first round, just as in an election held under the plurality system it is necessary to vote for one of the two leading candidates.
Runoff voting is also vulnerable to another tactic called "push over". This is a tactic by which voters vote tactically for an unpopular "push over" candidate in the first round as a way of helping their true favourite candidate win in the second round. The purpose of voting for the "push over", in theory, is to ensure that it is this weak candidate, rather than a stronger rival, who survives to challenge a one's preferred candidate in the second round. But in practice, such a tactic may prove counter-productive. If so many voters give their first preferences to the "weak" candidate that it ends up winning the first round, it is highly likely they will gain enough campaign momentum to have a strong chance of winning the runoff, too, and with it, the election. At the very least, their opponent would have to start taking the so-called "weak" candidate seriously, particularly if the runoff follows quickly after the first round.
Runoff voting can be influenced by strategic nomination
Strategic nomination
Strategic nomination is the manipulation of an election through its candidate set...
; this is where candidates and political factions influence the result of an election by either nominating extra candidates or withdrawing a candidate who would otherwise have stood. Runoff voting is vulnerable to strategic nomination for the same reasons that it is open to the voting tactic of "compromising". This is because a candidate who knows they are unlikely to win can ensure that another candidate they support makes it to the second round by withdrawing from the race before the first round occurs, or by never choosing to stand in the first place. By withdrawing candidates a political faction can avoid the "spoiler effect
Spoiler effect
The spoiler effect describes the effect a minor party candidate with little chance of winning has in a close election, when that candidate's presence in the election draws votes from a major candidate similar to them, thereby causing a candidate dissimilar to them to win the election...
", whereby a candidate "splits the vote" of its supporters. A famous example of this spoiler effect occurred in the 2002 French presidential election
French presidential election, 2002
The 2002 French presidential election consisted of a first round election on 21 April 2002, and a runoff election between the top two candidates on 5 May 2002. This presidential contest attracted a greater than usual amount of international attention because of Le Pen's unexpected appearance in...
, when so many left-wing candidates stood in the first round that all of them were eliminated and two right-wing candidates advanced to the second round. Conversely, an important faction may have an interest in helping fund the campaign of smaller factions with a very different political agenda, so that these smaller parties end up weakening their own agenda.
Impact on factions and candidates
Runoff voting encourages candidates to appeal to a broad cross-section of voters. This is because, in order to win an absolute majority in the second round, it is necessary for a candidate to win the support of voters whose favourite candidate has been eliminated. Under runoff voting, between rounds of voting eliminated candidates, and the factions who previously supported them, often issue recommendations to their supporters as to who to vote for in the second round of the contest. This means that eliminated candidates are still able to influence the result of the election. This influence leads to political bargaining between the two remaining candidates and the parties and candidates who have been eliminated, sometimes resulting in the two successful candidates making policy concessions to the less successful ones. Because it encourages concilliation and negotiation in these ways runoff voting is advocated, in various forms, by some supporters of deliberative democracyDeliberative democracy
Deliberative democracy is a form of democracy in which public deliberation is central to legitimate lawmaking. It adopts elements of both consensus decision-making and majority rule. Deliberative democracy differs from traditional democratic theory in that authentic deliberation, not mere...
.
Runoff voting is designed for single seat constituencies. Therefore, like other single seat methods, if used to elect a council or legislature
Legislature
A legislature is a kind of deliberative assembly with the power to pass, amend, and repeal laws. The law created by a legislature is called legislation or statutory law. In addition to enacting laws, legislatures usually have exclusive authority to raise or lower taxes and adopt the budget and...
it will not produce proportional representation
Proportional representation
Proportional representation 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...
(PR). This means that it is likely to lead to the representation of a small number of larger parties in an assembly, rather than a proliferation of small parties. In practice runoff voting produces results very similar to those produced by the plurality system, and encourages a two party system similar to those found in many countries that use plurality. Under a parliamentary system
Parliamentary system
A parliamentary system is a system of government in which the ministers of the executive branch get their democratic legitimacy from the legislature and are accountable to that body, such that the executive and legislative branches are intertwined....
it is more likely to produce single party governments than are PR systems, which tend to produce coalition government
Coalition government
A coalition government is a cabinet of a parliamentary government in which several political parties cooperate. The usual reason given for this arrangement is that no party on its own can achieve a majority in the parliament...
s. While runoff voting is designed to ensure that each individual candidate elected is supported by a majority of those in their constituency, if used to elect an assembly it does not ensure this result on a national level. As in other non-PR systems, the party or coalition which wins a majority of seats will often not have the support of an absolute majority of voters across the nation.
Majoritarianism
The intention of runoff voting is that the winning candidate will have the support of an absolute majority of voters. Under the "first past the post" system the candidate with most votes (a plurality) wins, even if they do not have an absolute majority (more than half) of votes. The two rounds system tries to overcome this problem by permitting only two candidates in the second round, so that one must receive an absolute majority of votes.Critics argue that the absolute majority obtained by the winner of runoff voting is an artificial one. As seen above, instant-runoff voting and the exhaustive ballot are two other voting systems that create an absolute majority for one candidate by eliminating weaker candidates over multiple rounds. However, as noted above in cases where there are 3 or more strong candidates, runoff voting will sometimes produce an absolute majority for a different winner than the candidate elected by the other two.
Advocates of Condorcet method
Condorcet method
A Condorcet method is any single-winner election method that meets the Condorcet criterion, which means the method always selects the Condorcet winner if such a candidate exists. The Condorcet winner is the candidate who would beat each of the other candidates in a run-off election.In modern...
s argue that a candidate can claim to have majority support only if they are the "Condorcet winner" – that is, the candidate who would beat every other candidate in a series of one-on-one elections. In runoff voting the winning candidate is only matched, one-on-one, with one of the other candidates. When a Condorcet winner exists, he does not necessarily win a runoff election due to insufficient support in the first round.
Runoff advocates counter that voters first preference is more important than lower preferences because that's where voters are putting the most effort of decision and that, unlike Condorcet methods, runoffs require a high showing among the full field of choices in addition to a strong showing in the final head-to-head competition. Condorcet methods can allow candidates to win who have minimal first-choice support and can win largely on the compromise appeal of being ranked second or third by more voters.
Practical implications
In large-scale public elections the two rounds of runoff voting are held on separate days, and so involve voters going to the polls twice. In smaller elections, such as those in assemblies or private organisations, it is sometimes possible to conduct both rounds in quick succession. However the fact that it involves two rounds means that, for large elections, runoff voting is more expensive than some other electoral systems. It may also lead to voter fatigueVoter fatigue
In politics, voter fatigue is the apathy that the electorate can experience when they are required to vote too often.It is often used as a criticism of the direct democracy system, in which voters are constantly asked to decide on policy via referenda...
and a reduced turn-out
Voter turnout
Voter turnout is the percentage of eligible voters who cast a ballot in an election . After increasing for many decades, there has been a trend of decreasing voter turnout in most established democracies since the 1960s...
in the second round. In French elections the second round seldom has a turn-out as high as the first. In runoff voting, the counting of votes in each round is simple and occurs in the same way as under the plurality system. Preferential voting
Preferential voting
Preferential voting is a type of ballot structure used in several electoral systems in which voters rank candidates in order of relative preference. For example, the voter may select their first choice as '1', their second preference a '2', and so on...
systems, such as instant-runoff voting, involve a longer, more complicated count.