Editing Plurality voting (section)

==== 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}}</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>