Editing Plurality voting (section)

=== In all plurality systems ===

==== Wasted votes ====
[[File:Vote 12345-en.svg|thumb|A ballot with a potential wasted vote goes into the voting box]]
[[Wasted vote]]s are those cast for candidates or parties who did not get elected. Some number of wasted votes by this definition is practically unavoidable, but plurality systems suffer from large numbers of wasted votes. For example, in the [[2005 United Kingdom general election|UK general election of 2005]], 52% of votes were cast for losing candidates and 18% were excess votes, a total of 70% wasted votes. That is perhaps the most fundamental criticism of FPTP, the single-member plurality system, since at least half the votes are always wasted in a district, either as being placed on un-elected candidates or being surplus to what could be needed to win.

SMP is in practice similar in plurality block voting. They both operate under the "winner-takes-all" principle, which means that the party of the losing candidates in each district receive no representation, regardless of the number of votes they receive.<ref name=":4">{{Cite journal |last=Verma |first=Dhruv |date=2021-01-01 |title=Reflecting People's Will: Evaluating elections with computer aided simulations |journal=Open Political Science |language=en |volume=4 |issue=1 |pages=228–237 |doi=10.1515/openps-2021-0021 |issn=2543-8042 |s2cid=236980393 |doi-access=free}}</ref> Even the single non-transferable vote can result in very inefficient results if many candidates with small support compete or the most-popular candidates receive a large excess of votes. This is because like other plurality systems,  SNTV does not transfer loser and surplus votes.

Another way to count wasted votes, is to see the ones that may play no part in determining the outcome.<ref name=":2">{{Cite journal |last1=Whitelock |first1=Amy |last2=Whitelock |first2=Jeryl |last3=van Heerde |first3=Jennifer |date=2010-04-06 |editor-last=Harris |editor-first=Phil |title=The influence of promotional activity and different electoral systems on voter turnout: A study of the UK and German Euro elections |url=https://www.emerald.com/insight/content/doi/10.1108/03090561011020499/full/html |journal=European Journal of Marketing |language=en |volume=44 |issue=3/4 |pages=401–420 |doi=10.1108/03090561011020499 |issn=0309-0566|url-access=subscription }}</ref> Under FPTP for example, usually only votes for the top two candidates can be seen as really competing for the position, with only one possible to win; votes placed on other candidates are almost certain not to be used to elect anyone and therefore wasted. Sometimes not even two candidate are seen as being competitive. Due to having a history of repeatedly electing candidates of a certain party, many districts are known to have [[safe seat]]s. On such, a candidate or party has a near 100% chance that they win the seats. Supporters of others sometimes do not even bother to vote knowing of the odds that face their candidate.

Alternative electoral systems, such as [[proportional representation]], attempt to ensure that almost all of the votes are effective in influencing the result and electing a representative, which minimizes vote wastage.<ref>{{Citation |last1=Blais |first1=André |title=Voter Turnout |date=2013-06-25 |work=Political Science |url=https://oxfordbibliographies.com/view/document/obo-9780199756223/obo-9780199756223-0066.xml |access-date=2022-04-15 |publisher=Oxford University Press |language=en |doi=10.1093/obo/9780199756223-0066 |isbn=978-0-19-975622-3 |last2=Anduiza |first2=Eva |doi-access=free}}</ref> Such systems decreases disproportionality in election results and are also credited for increasing voter turnout.<ref>{{Cite journal |last=Blais |first=André |date=2006-06-01 |title=What affects voter turnout? |journal=Annual Review of Political Science |volume=9 |issue=1 |pages=111–125 |doi=10.1146/annurev.polisci.9.070204.105121 |issn=1094-2939 |doi-access=free}}</ref>

==== Tactical voting ====
{{more citations needed|section|date=February 2019}}
{{see also|Tactical voting#Plurality voting}}
To a much greater extent than many other electoral methods, plurality electoral systems encourage [[tactical voting]] techniques like "compromising".<ref>{{Cite journal |last1=Dolez |first1=Bernard |last2=Laurent |first2=Annie |last3=Blais |first3=André |date=2017-04-01 |title=Strategic voting in the second round of a two-round system: The 2014 French municipal elections |url=https://doi.org/10.1057/s41253-016-0010-9 |journal=French Politics |language=en |volume=15 |issue=1 |pages=27–42 |doi=10.1057/s41253-016-0010-9 |s2cid=151584816 |issn=1476-3427|url-access=subscription }}</ref> Voters are under pressure to vote for one of the two candidates most likely to win, even if their true preference is neither of them; because a vote for any other candidate is unlikely to lead to the preferred candidate being elected. In single-member plurality, this will instead reduce support for one of the two major candidates whom the voter might prefer to the other. Electors who prefer not to waste their vote by voting for a candidate with a very low chance of winning their constituency vote for their lesser preferred candidate who has a higher chance of winning.<ref name=":5">{{Cite journal |last1=Blais |first1=André |last2=Nadeau |first2=Richard |last3=Gidengil |first3=Elisabeth |last4=Nevitte |first4=Neil |date=2001-09-01 |title=Measuring strategic voting in multiparty plurality elections |url=https://www.sciencedirect.com/science/article/pii/S0261379400000172 |journal=Electoral Studies |language=en |volume=20 |issue=3 |pages=343–352 |doi=10.1016/S0261-3794(00)00017-2 |issn=0261-3794|url-access=subscription }}</ref> The minority party will then simply take votes away from one of the major parties, which could change the outcome and gain nothing for the voters. Any other party will typically need to build up its votes and credibility over a series of elections before it is seen as electable.

In the [[#Example|Tennessee example]], if all the voters for Chattanooga and Knoxville had instead voted for Nashville, Nashville would have won (with 58% of the vote). That would have only been the third choice for those voters, but voting for their respective first choices (their own cities) actually results in their fourth 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". That is because by voting for other candidates, voters have denied those votes to the second-place candidate, who could have won had they received them. It is often claimed by United States [[Democratic Party (United States)|Democrats]] that Democrat [[Al Gore]] lost the [[2000 U.S. presidential election|2000 Presidential Election]] to [[Republican Party (United States)|Republican]] [[George W. Bush]] because some voters on the left voted for [[Ralph Nader]] of the [[Green Party of the United States|Green Party]], who, exit polls indicated, would have preferred Gore at 45% to Bush at 27%, with the rest not voting in Nader's absence.<ref>{{Cite news |last=Rosenbaum |first=David E. |date=2004-02-24 |title=The 2004 Campaign: the Independent; Relax, Nader Advises Alarmed Democrats, but the 2000 Math Counsels Otherwise |work=[[The New York Times]] |url=https://query.nytimes.com/gst/fullpage.html?res=9B03E4D6173CF937A15751C0A9629C8B63 |access-date=2010-05-08}}</ref>

That thinking is illustrated by elections in [[Puerto Rico]] and its three principal voter groups: the [[Puerto Rican Independence Party|Independentistas]] (pro-independence), the [[Popular Democratic Party (Puerto Rico)|Populares]] (pro-[[Commonwealth (U.S. insular area)|commonwealth]]), and the [[New Progressive Party (Puerto Rico)|Estadistas]] (pro-[[U.S. state|statehood]]). Historically, there has been a tendency for Independentista voters to elect Popular candidates and policies. This results in more Popular victories even though the Estadistas have the most voters on the island. It is so widely recognised that the Puerto Ricans sometimes call the Independentistas who vote for the Populares "melons" in reference to the party colours, because the fruit is green on the outside but red on the inside.

Such tactical voting can cause significant perturbation to the system:

*Substantial power is given to the [[news media]]. Some voters will tend to believe the media's assertions as to who the leading contenders are likely to be in the election. Even voters who distrust the media know that other voters believe the media, and so those candidates who receive the most media attention will nonetheless be the most popular, and thus most likely to be one of the top two.
*A new candidate, who is in principle supported by the majority of voters, may be considered unlikely to become one of the top two candidates, because of the lack of a track record. The candidate will thus receive fewer votes, which will then give them a reputation as a low poller in future elections, which perpetuates the problem.
*The system may promote votes against than for a candidate. In the UK, entire campaigns have been organised with the aim of voting against the [[Conservative Party (UK)|Conservative Party]] by voting either [[Labour Party (UK)|Labour]] or [[Liberal Democrats (UK)|Liberal Democrat]]. For example, in a [[United Kingdom constituencies|constituency]] held by the Conservatives, with the Liberal Democrats as the second-placed party and the Labour Party in third, Labour supporters might be urged to vote for the Liberal Democrat candidate, who has a smaller hurdle to overcome and more support in the constituency than their own party candidate, on the basis that Labour supporters would prefer an MP from a competing leftist or liberal party than a Conservative one. Similarly, in Labour/Liberal Democrat marginals in which the Conservatives are third, Conservative voters may be encouraged or tempted to vote Liberal Democrat to help defeat Labour.
*If enough voters use this tactic, the first-past-the-post system becomes, effectively, [[Two-round system|runoff voting]], a completely different system, in which the first round is held in the court of public opinion. A good example was the [[1997 Winchester by-election]].

Proponents of other single-winner electoral systems argue that their proposals would reduce the need for tactical voting and reduce the [[spoiler effect]]. Other systems include the commonly used [[two-round system]] of runoffs and [[instant-runoff voting]], along with less-tested and perhaps less-understood systems such as [[approval voting]], [[score voting]] and [[Condorcet methods]].

[[Tactical voting]] is when a voter decides to vote in a way that does not represent their true preference or choice, motivated by an intent to influence election outcomes.<ref>{{Cite journal |last=Hartvigsen |first=David |date=2008 |title=The Manipulation of Voting Systems |url=https://www.jstor.org/stable/41219187 |journal=Journal of Business Ethics |volume=80 |issue=1 |pages=13–21 |doi=10.1007/s10551-007-9438-9 |issn=0167-4544 |jstor=41219187 |s2cid=153895999|url-access=subscription }}</ref> Strategic behaviour by voters can and does influence the outcome of voting in different plurality voting systems. Strategic behaviour is when a voter casts their vote for a different party or alternative district/constituency/riding{{clarify|date=August 2023}} in order to induce, in their opinion, a better outcome. An example of this is when a person really likes party A but votes for party B because they do not like party C or D or because they believe that party A has little to no chance of winning.<ref name=":1">{{Cite journal |last1=Bassi |first1=Anna |year=2015 |title=Voting Systems and Strategic Manipulation: an Experimental Study |url=https://www.researchgate.net/publication/228632824 |journal=Journal of Theoretical Politics |language=en |volume=27 |pages=58–85 |doi=10.1177/0951629813514300 |s2cid=4471874}}</ref> This can cause the outcome of very close votes to be swayed for the wrong reason. This might have had an impact on the [[2000 United States presidential election|2000 United States election]] that was essentially decided by fewer than 600 votes, with the winner being [[George W. Bush|President Bush]]. When voters behave in a strategic way and expect others to do the same, they end up voting for one of the two leading candidates, making the Condorcet alternative more likely to be elected.<ref name=":1" /> The prevalence of strategic voting in an election makes it difficult to evaluate the true political state of the population, as their true political ideologies are not reflected in their votes.<ref name=":5" />

==== Spoiler effect ====
{{Main|Spoiler effect}}

The spoiler effect is especially severe in plurality voting, where candidates with similar ideologies are forced to split the vote with each other.<ref name=":4" /> One spoiler candidate's presence in the election draws votes from a major candidate with similar politics, which causes a strong opponent of both or several to win.<ref name=":4" /> Even extremely small parties with very little first-preference support can therefore affect the outcome of an FPTP election.<ref name=":4" />

==== Manipulation charges ====
The presence of [[spoiler (politician)|spoilers]] often gives rise to suspicions that [[strategic nomination|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, which induces charges that such an act was intended from the beginning. Voters who are uninformed do not have a comparable opportunity to manipulate their votes as voters who understand all opposing sides, understand the pros and cons of voting for each party.

==== Gerrymandering ====
Because FPTP permits a high level of wasted votes, an election under FPTP is easily gerrymandered unless safeguards are in place.<ref>{{Cite journal |last1=Johnston |first1=Ron |last2=Rossiter |first2=David |last3=Pattie |first3=Charles |last4=Dorling |first4=Danny |date=2002 |title=Labour electoral landslides and the changing efficiency of voting distributions |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/1475-5661.00058 |journal=Transactions of the Institute of British Geographers |language=en |volume=27 |issue=3 |pages=336–361 |bibcode=2002TrIBG..27..336J |doi=10.1111/1475-5661.00058 |issn=1475-5661|url-access=subscription }}</ref> In [[gerrymandering]], a party in power deliberately manipulates constituency boundaries to increase the number of seats that it wins unfairly.

In brief, if a governing party G wishes to reduce the seats that will be won by opposition party O in the next election, it can create a number of constituencies in each of which O has an overwhelming majority of votes. O will win these seats, but many of its voters will waste their votes. Then, the rest of the constituencies are designed to have small majorities for G. Few G votes are wasted, and G will win many seats by small margins. As a result of the gerrymander, O's seats have cost it more votes than G's seats.

'''Efficiency gap''': The ''[[efficiency gap]]'' measures gerrymandering and has been scrutinized in the Supreme Court of the United States.<ref>{{cite news |title=Here's how the Supreme Court could decide whether your vote will count |url=https://www.washingtonpost.com/graphics/2017/politics/courts-law/gerrymander/ |newspaper=[[The Washington Post]]}}</ref><ref>{{cite journal |last1=McGhee |first1=Eric |year=2020 |title=Partisan Gerrymandering and Political Science |journal=Annual Review of Political Science |volume=23 |pages=171–185 |doi=10.1146/annurev-polisci-060118-045351 |doi-access=free}}</ref> The efficiency gap is the difference between the two parties' wasted votes, divided by the total number of votes.<ref name="82UofCLawReview">{{Cite journal |last1=Stephanopoulos |first1=Nicholas |last2=McGhee |first2=Eric |year=2014 |title=Partisan Gerrymandering and the Efficiency Gap |journal=University of Chicago Law Review |volume=82 |pages=831–900 |ssrn=2457468}} Wasted votes and efficiency gap are defined pp. 850–852.</ref><ref name="NewRepublic20140702">{{Cite magazine |last=Stephanopoulos |first=Nicholas |date=2 July 2014 |title=Here's How We Can End Gerrymandering Once and for All |url=https://newrepublic.com/article/118534/gerrymandering-efficiency-gap-better-way-measure-gerrymandering |access-date=2016-11-22 |magazine=The New Republic}}</ref>