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Two-round system: Difference between revisions
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{{Wikipedia|Two-round system}}
'''Runoff voting''' is a [[voting system]] used in single-seat [[election]]s. It is used widely around the world, including in elections for the [[President of France]] and [[President of Finland|Finland]], and especially in a [[political party]]'s [[primary election]]s, in which it selects candidates to present to the public.▼
[[File:TRS ballot papers.svg|thumb|325px|An example of runoff voting. Runoff voting involves two rounds of voting, and only two candidates survive to the second round.]]
▲The '''
It generally ensures a [[majoritarian]] result, not a simple plurality result as under [[First past the post]]. Under the two-round election system, the election process usually proceeds to a second round only if in the first round no candidate received a [[Majority|simple majority]] (more than 50%) of votes cast, or some other lower prescribed percentage.<ref>{{Cite web |title=Two-Round System |url=https://www.electoral-reform.org.uk/voting-systems/types-of-voting-system/two-round-system/ |access-date=7 Nov 2019 |website=Electoral Reform Society}}</ref> Under the two-round system, usually only the two candidates who received the most votes in the first round, or only those candidates who received above a prescribed proportion of the votes, are candidates in the second round. Other candidate are excluded from the second round.
The two-round system is widely used in the election of legislative bodies and directly elected presidents, as well as in other contexts, such as in the election of political party leaders or within companies.
== Voting ==▼
The second round of voting must be held after there is sufficient time to count and verify the results of the first round. Second rounds may be held on the same day in smaller settings, or up to three months later, as in the US state of [[Georgia]]. France traditionally has a two-week break before the second round.
In the preliminary election, voters select their preferred candidate. If one candidate reaches the election threshold (usually fifty percent of the positive votes plus one), they are elected.
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Runoff voting can be condensed into a single preference ballot paper, at which point it becomes [[instant-runoff voting]] or an "alternative vote". A simplified model of a two round system is the [[supplementary vote]].
A runoff ballot is not the same thing as a [[primary election]]. In a runoff ballot, all candidates are placed on the
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{{Tenn_voting_example}}
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*Memphis: 42%
*Knoxville: 32%
*Nashville: 26%
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So Knoxville would win.
==
The runoff system encourages voters to "compromise" by not voting for their favorite candidate in their first round. In the above two-round example, if all voters from Chattanooga "compromised" for Knoxville in the first round, Knoxville would advance to the second round, where it would defeat Memphis. This would be a better result for the Chattanooga voters than sincere voting would get them. The Memphis supporters voters could respond by voting for Nashville instead of Memphis as a way to prevent Knoxville or Chattanooga winning.
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Runoff voting can also encourage voters to vote for "push-overs", in order to set up a more favorable second-round matchup.
== Impact of
A two-round runoff voting system, in practice, may work as a system of [[primary election]]s in countries where there are two major partisan blocks, by choosing for the second round of election a candidate in each block. While this is the usual outcome, different situations may arise in the presence of coalitions fielding multiple candidates, protest votes and third parties.
A striking example, which attracted considerable media attention, was that of the [[French presidential election, 2002|2002 French presidential election]]. The two major contenders, respectively leading a left-wing and a right-wing coalition, were [[Lionel Jospin]] and [[Jacques Chirac]]. However, the left-wing coalition fielded three additional candidates representing minor parties in the coalition. Furthermore, part of the left-wing vote went to candidates from far-left parties, presumably to protest Jospin's policies, deemed too centrist. A third important candidate was [[Jean-Marie Le Pen]], a controversial politician often described as racist and fascist-leaning. On the first round of elections:
*
*
While it is not established that voters for minor candidates of each coalition would have voted for the major candidate of the same coalition, these sums would tend to indicate that Jospin had a slight edge over Chirac.
Le Pen, however, obtained 16.86% and thus went to the second round of election against Chirac. Since the vast majority of the electorate disapproves of Le Pen's policies, Chirac then won by an enormous majority (82.21%). In the last decades, normal second rounds in French presidential elections were settled around 50% for each side.
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Between each round of voting, discussion and dealing is possible; policy concessions and withdrawals can be negotiated. Accordingly, runoff votes in some form are advocated as part of most [[deliberative democracy]] proposals. Other [[electoral reform]] and [[grassroots democracy]] advocates prefer [[instant-runoff voting]] which let larger groups participate in the process by ballot - the French participation of the whole electorate in a runoff vote is a rare exception and permits some dealing between parties who have lost and those who seek their support.
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The one-ballot "instant runoff" proposals are the opposite of such 'deliberative' processes, as there is no time nor place for explicit discussion and dealing as the power relationships become clear. Polls can take the place of early rounds of balloting, but are nowhere near as statistically valid as a formal vote.
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The runoff voting rule satisfies a weak form of the [[dominant mutual third]] property, and thus a weak form of the [[mutual majority criterion]]: if over 1/3rd of voters vote for a candidate that [[Pairwise beat|pairwise beats]] all candidates not in a certain set of candidates most-preferred by the 1/3rd of voters (because they are a [[solid coalition]]), then someone from that set of candidates (i.e. the one that gets over 1/3rd of the votes) will win in the runoff. <ref name="Kondratev Nesterov 2017">{{cite journal | last=Kondratev | first=Aleksei Y. | last2=Nesterov | first2=Alexander S. | title=Weak Mutual Majority Criterion for Voting Rules | journal=IEEE Communications Standards Magazine | date=2018 | url=https://www.semanticscholar.org/paper/Weak-Mutual-Majority-Criterion-for-Voting-Rules-Kondratev-Nesterov/2c934e191ef52b9f2fb16d81046cfe86b3f9d36e | access-date=2022-02-27}}</ref> [[Instant-runoff voting]] satisfies a stronger version of the property.
Sometimes Top Two Runoff (TTR) is also used as the name of an automatic one-round variation, which works by having voters rank the candidates, finding the two candidates ranked 1st by the most voters, and then using the rankings to figure out which of the two is preferred by a majority and electing that one. This method is more properly called the [[contingent vote]].
It has been theorized that when runoff elections are held with the possibility of a candidate with a majority winning in the first round itself, that this actually incentivizes voters to do [[Favorite Betrayal]] to make a frontrunner have an "extra chance" to win (i.e. the frontrunner, who might lose in the runoff due to lower turnout or other factors, will instead win in the first round).<ref name="Bouton 2013 pp. 1248–1288">{{cite journal | last=Bouton | first=Laurent | title=A Theory of Strategic Voting in Runoff Elections | journal=The American Economic Review | volume=103 | issue=4 | year=2013 | issn=00028282 | jstor=23469618 | pages=1248–1288 | url=http://www.jstor.org/stable/23469618 | access-date=2022-02-27}}</ref><ref>{{Cite journal|last=Bouton|first=Laurent|last2=Gratton|first2=Gabriele|date=2015|title=Majority runoff elections: Strategic voting and Duverger's hypothesis|url=https://onlinelibrary.wiley.com/doi/abs/10.3982/TE1642|journal=Theoretical Economics|language=en|volume=10|issue=2|pages=283–314|doi=10.3982/TE1642|issn=1555-7561}}</ref> Thus, it has been argued by some that a second round should always be held even if someone gets a majority in the first round. This could be modified to allow a candidate with a supermajority (say, 60%) to win in the first round, however, since the larger the majority, the less such incentive is likely to exist.
==See also==
*[[First Past the Post electoral system]]
*[[Instant-runoff voting]]
*[[primary election]]
* [[deliberative democracy]]
{{fromwikipedia}}
[[Category:Single-winner voting
[[Category:Single-mark ballot voting methods]]
[[Category:Plurality-runoff voting methods]]
[[Category:FPTP-based voting methods]]
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