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The referendum 28 months on. Dr. Chris Hanretty, Royal Holloway, University of London Introduction In June of 2016, the UK voted to leave the European Union. 28 months have passed since then, and public opinion has changed. The referendum was counted, not in Westminster constituencies, but in local authority areas. Just looking at counting areas in England, Scotland and Wales, around seven in ten local authority areas voted to leave, or 263 in total. How would that look if we re-ran the referendum now? We can use a tool called multilevel regression and post-stratification (MRP) to answer that question. This tool models the opinions of respondents to a large national survey – in this case, a survey of around 20,000 people. Those opinions are linked to people’s demographic characteristics – things like their age, their highest educational qualifications. Using the census, it’s possible to look up how many people of each type live in each area, and make predictions about how each type thinks. By adding up the predictions for each type, we get an estimate of how each area might vote. It’s not infallible, but it’s our best guide to local opinion. Using that tool, how would the results of the referendum look now? Well, according to this analysis, the average support for Leave across Great Britain, looking just at those who would be likely to turnout to vote, would be 45.6% – some seven points down on the figure from 2016. That means that far fewer local authority areas would be likely to vote leave: around 158, or closer to four in ten areas. That seems like a radical shift – but a lot of these changes in opinion are gradual. The places that most supported Leave in 2016 are still the places that most support leave now. You can see that in Figure 1, which shows the support for Leave in 2016 along the horizontal axis, against support for Leave in a hypothetical referendum held today.

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Page 1: The referendum 28 months on. Dr. Chris Hanretty, Royal ... · We can use a tool called multilevel regression and post-stratification (MRP) to answer that question. This tool models

The referendum 28 months on.

Dr. Chris Hanretty, Royal Holloway, University of London

Introduction InJuneof2016,theUKvotedtoleavetheEuropeanUnion.

28monthshavepassedsincethen,andpublicopinionhaschanged.

Thereferendumwascounted,notinWestminsterconstituencies,butinlocalauthorityareas.

JustlookingatcountingareasinEngland,ScotlandandWales,aroundsevenintenlocalauthorityareasvotedtoleave,or263intotal.

Howwouldthatlookifwere-ranthereferendumnow?

Wecanuseatoolcalledmultilevelregressionandpost-stratification(MRP)toanswerthatquestion.Thistoolmodelstheopinionsofrespondentstoalargenationalsurvey–inthiscase,asurveyofaround20,000people.

Thoseopinionsarelinkedtopeople’sdemographiccharacteristics–thingsliketheirage,theirhighesteducationalqualifications.Usingthecensus,it’spossibletolookuphowmanypeopleofeachtypeliveineacharea,andmakepredictionsabouthoweachtypethinks.Byaddingupthepredictionsforeachtype,wegetanestimateofhoweachareamightvote.It’snotinfallible,butit’sourbestguidetolocalopinion.

Usingthattool,howwouldtheresultsofthereferendumlooknow?Well,accordingtothisanalysis,theaveragesupportforLeaveacrossGreatBritain,lookingjustatthosewhowouldbelikelytoturnouttovote,wouldbe45.6%–somesevenpointsdownonthefigurefrom2016.

Thatmeansthatfarfewerlocalauthorityareaswouldbelikelytovoteleave:around158,orclosertofourintenareas.

Thatseemslikearadicalshift–butalotofthesechangesinopinionaregradual.TheplacesthatmostsupportedLeavein2016arestilltheplacesthatmostsupportleavenow.YoucanseethatinFigure1,whichshowsthesupportforLeavein2016alongthehorizontalaxis,againstsupportforLeaveinahypotheticalreferendumheldtoday.

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SupportforLeaving,thenandnow.EachdotrepresentsalocalauthorityareainGreatBritain.Thebluelineindicatesthelineofbestfit.Thesolidlineshowshowthelineswouldfallifnoonechangedtheirmind.

Thebluelineinthefigureisatrendline.Itrunsprettyclosetothesolidline(whichshowswhatwouldhappenifnothingchanged),butitisslightlyflatter.ThatmeansthatRemainvotingareasstayasRemainastheyeverwere,whilstLeave-votingareasareactuallyswitchingathigherrates.

ThiscanbeseeninFigure2,whichratherthanplotsupportforLeavingtoday,plotstheestimatedchangeintheLeavevotesharebetween2016and2018.Thelargestpanel,onthelefthandside,plotstherelationshipbetweentheLeavevotein2016andthechange.Therelationshipisnegative:thebiggertheLeavevotein2016,themoretheareahasswungroundtoRemain,evenifitstartedfromaLeavierstartingpoint.

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Threepatternsofchange.SwitchesawayfromLeavearegreaterthestrongertheinitialsupportforLeave(left-handpanel).SwitchesawayfromLeaveareweakerthestrongerinareasthatvotedConservativeinthe2014EPelections(top-rightpanel).There’snosimplerelationshipwiththeUKIPvote(bottomrightpanel).

ThetoprighthandpanelofFigure2showsthepatternsofchangeaccordingtoConservativesupportinthe2014EuropeanParliamentelections.We’reusingthe2014EuropeanParliamentelectionsbecausethesetoowerecountedatthelocalauthoritylevel.Astheplotshows,theswitchawayfromLeaveissmallerthebettertheConservativesdid.Conservative-votingareasaremorelikelytostickwithLeave–or,conversely,Labourareasaremorelikelytoswitch.

ThebottomrighthandpanelshowsthesamefigurebutforUKIPsupportin2014.Here,therelationshipisessentiallyflat:there’snosimplerelationship.However,becauseUKIPsupportin2014wassuchastrongpredictoroftheLeavevote,thismeansthatifwecontrolfortheLeavevote,wefindthatareaswhichwerestrongerbedsofsupportforUKIPare,justlikeConservativevotingareas,morelikelytostickwithLeave.

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ChangeinsupportforLeavingbyregion.Thereddotgivestheaveragechangebyregion.

Youmightwonderwhethertheseestimatesarerobust.Dotheychangemuchifwechangesomeoftheassumptions?

Ifweignorequestionsofturnout,andassumethateveryonevotesinafreshreferendum,thenthefiguresdon’tchangemuch.Wegofrom45.6percentto45.9percent-atinydifference.

Whataboutourconfidenceintheestimatesforeachplace–canwesummarizetheseestimatesinasinglefigure,ordoweneedarangeoffigures?

Ifwe’dconductedastandardpollineacharea,thenthemarginoferrorforeachlocalauthoritywouldbeplusorminusthreepercent.Butbecausewehaven’tconducted380thousandinterviews,wehavetosettleforsomethingless–plusorminusfivepercentineachcase.

Thatmeansthatalthoughweknowalotofareashaveswitched,wecanonlybereallyveryconfidentaboutamuchsmallergroup.Herearetheareasmostlikelytohaveswitched:

• Nottingham(40.1%Leavenowbutwas50.8%Leavethen).• Luton(43.8%Leavenowbutwas56.5%Leavethen).• Slough(41.6%Leavenowbutwas54.3%Leavethen).• Southampton(41.8%Leavenowbutwas53.8%Leavethen).• HighPeak(44.3%Leavenowbutwas50.5%Leavethen).

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• Watford(43.6%Leavenowbutwas50.3%Leavethen).• Canterbury(44.6%Leavenowbutwas51%Leavethen).• Cherwell(44.5%Leavenowbutwas50.3%Leavethen).• ReigateandBanstead(44.9%Leavenowbutwas50.5%Leavethen).• Knowsley(39.7%Leavenowbutwas51.6%Leavethen).• NorthTyneside(45.5%Leavenowbutwas53.4%Leavethen).• Birmingham(41.8%Leavenowbutwas50.4%Leavethen).• Sutton(44.9%Leavenowbutwas53.7%Leavethen).• IsleofAnglesey(44.2%Leavenowbutwas50.9%Leavethen).• Swansea(43.2%Leavenowbutwas51.5%Leavethen).• RhonddaCynonTaf(43.5%Leavenowbutwas53.7%Leavethen).

Aswellasaskinghowpeoplewouldvoteinafreshreferendum,wealsoaskedhowpeoplewouldviewparticularproposals,andhowtheywouldvoteonaneventualdeal.

Hereweretheparticularproposalsweasked,togetherwiththeoverallsupport(notincludingthosethatsaiddon’tknow)

• newchecksbeingintroducedongoodscrossingtheIrishseabetweenNorthernIrelandandtherestoftheUK(41%)

• UKandEUcitizenswhowishedtodosobeingabletoliveandworkineachother’scountries

(76%) • LimitationsontheUK’sabilitytomaketradedealswithcountriesoutsidetheEU(25%) • FollowingEUregulationsonmanufacturedgoodssuchasfridges,vacuumcleanersandlightbulbs

(62%) • Supportforthedealasitstands(43%)

Theseproposalshaveverydifferentpatternsofsupport.Thisisshowninthenextfigure,whichshowshoweachareavotedin2016,againstitscurrentsupportforeachproposal.

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Theassociationbetweenhoweachareavotedin2016,andhowmuchtheywouldsupportparticularproposalsifthesewerethepriceofadealbetweentheEUandtheUK

Asyoucansee,thehigherthe2016voteforLeave,thelowerthesupportforcontinuingfreedomofmovement,andthelowerthesupportforcontinuingtoacceptEUregulations–eveniftheoveralllevelofsupportfortheseproposalsisquitehigh.

ThestoryisquitedifferentforgoodschecksintheIrishsea,andforlimitationsontradedeals.Thesehavemuchlowersupport,butthey’realsomuchlessstronglyassociatedwiththe2016Leavevote.

Thefinalplotshowstherelationshipbetweenhoweachareavotedin2016,andhowtheywouldvoteonthepresentdeal,howevertheyunderstandthat.

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Supportforthecurrentdeal.

Surprisingly,it’sLeave-votingareaswhicharemorelikelytosupportthedeal,eventhoughsupportisnothigh.Remain-votingareasmaybeholdingoutforsomethingbetter.

Full data by local authority can be found here:

https://www.survation.com/wp-content/uploads/2018/11/LA-predictions-from-MRP-1.xlsx