Glenshane: New Boundaries 2018 Calculation

Glenshane: Overview

 Projection: NAT seat 

Implied MP at 2015: Unknown (changed seat)  (NAT)
County/Area: Londonderry (Northern Ireland)
Electorate: 73,833
Turnout: 54.8%

 Implied 2015 VotesImplied 2015 Share
NAT14,97437.0%
LIB11,81129.2%
CON4,83912.0%
LAB4,81711.9%
MIN2,4096.0%
OTH1,2463.1%
UKIP3690.9%
NAT Majority3,1637.8%

See overview of other seats in Northern Ireland.

Glenshane: Map

Boundary Lines courtesy of Ordnance Survey OpenData © Crown copyright 2015

Introduction

This page shows the detail of the calculations performed to estimate the general election result for 2015 had the new boundaries for Glenshane been in force at that time. The basic idea of the calculation is to look at the district council wards which make up the new seat, and estimate how they voted in 2015. This estimate is based on the recent local election results in those wards, with adjustments made to allow for different turnouts and different voting patterns for local and general elections.

In many cases, wards are divided between several old constituencies or between new constituencies. So the same ward may be shown more than once, but the electorate shown will reflect that ward sub-section.

Election results from a recent local election are given. This is usually the local election closest to 2015 from the period 2012-2015. For multiple-member wards, the votes shown are the sum of the votes cast for all candidates of each party. A negative number indicates candidate(s) elected unopposed.

Calculation method

There are two problems with using the raw (actual) local election results to imply general election results ward-by-ward. Firstly, turnout can be different between local and general elections, which means that the total number of local votes cast does not equal the number of votes cast in each old seat at the general election. To correct for this, we adjust the local votes to match the general election turnout. Each ward's result is scaled, whilst keeping constant the percentage support for each party, so that the total turnout adds up to the old seat's general election turnout. All wards in the old seat are assumed to have the same percentage turnout.

Secondly, even though we now have the correct number of votes in the old seat, the party totals will not match the general election result. Some parties do better at the local election than the general election, and others do vice versa. We call these strong and weak parties respectively. The next step is to transfer votes from strong parties to weak parties. This is done by taking votes proportionally away from strong parties and putting them in a transfer pool. For instance if a party got 12,500 local votes, but only 10,000 general election votes, it will lose 20% over all the wards. These votes in each ward will be put in the ward's transfer pool and allocated to the weak parties. Weak parties will get votes transferred to them in proportion to the votes they need over the old seat. For instance, if two weak parties need 4,000 and 1,000 votes respectively, the first party will get 80% of each ward's transfer pool and the second party will get 20% of each ward's transfer pool. The transfer of votes between parties is done using the Electoral Calculus Transition Model.

More details of the calculation formulas are available.

List of old seats forming part of Glenshane

The old seat(s) needed are:

Old seat: Foyle

The table shows the transfer-adjusted results for each ward in the old seat of Foyle, as well as showing which new seat each ward is in.

Old seat: FoyleTransfer-adjusted Results
DistrictWardElectorate
2015
New SeatUUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
Derry and StrabaneBallymagroarty2,899Foyle09375505235481,532
Derry and StrabaneBrandywell2,458Foyle06163406343761,300
Derry and StrabaneCarn Hill2,228Foyle06703304702841,178
Derry and StrabaneCaw2,973Foyle1515674489502901731,571
Derry and StrabaneCity Walls2,395Foyle06003406173661,266
Derry and StrabaneClaudy13Glenshane132001007
Derry and StrabaneClondermot2,468Foyle1254723717902411421,304
Derry and StrabaneCreggan2,352Foyle05893306063561,242
Derry and StrabaneCreggan South2,203Foyle05523305673351,163
Derry and StrabaneCulmore2,942Foyle08853406213661,555
Derry and StrabaneDrumahoe2,924Foyle1485584409302851731,544
Derry and StrabaneEbrington2,751Foyle1405254148702681621,452
Derry and StrabaneEglinton2,720Foyle715564614602702951,438
Derry and StrabaneEnagh2,850Foyle755834834802833051,507
Derry and StrabaneFoyle Springs2,216Foyle07174403994171,172
Derry and StrabaneGalliagh2,879Foyle08663406073661,522
Derry and StrabaneKilfennan2,899Foyle1475554369102831731,532
Derry and StrabaneLisnagelvin2,475Foyle1264723737902421421,308
Derry and StrabaneMadam's Bank2,520Foyle08154404544771,331
Derry and StrabaneNew Buildings2,534Foyle665184304302512741,339
Derry and StrabaneNorthland3,127Foyle01,0115505645891,652
Derry and StrabaneShantallow2,460Foyle07403305193051,300
Derry and StrabaneShantallow East2,992Foyle09003406313761,581
Derry and StrabaneSheriff's Mountain2,497Foyle06253406433761,318
Derry and StrabaneSkeoge2,823Foyle08493305953561,491
Derry and StrabaneSlievekirk1,481Foyle39303251250147163784
Derry and StrabaneSpringtown2,252Foyle07294404054271,191
Derry and StrabaneVictoria2,706Foyle1385184078602631621,430
 Total70,037 1,22717,7314,571833011,67983513437,010

The full details of these calculations are given on the Foyle seat details page. Click on "Show workings".

Old seat: Londonderry East

The table shows the transfer-adjusted results for each ward in the old seat of Londonderry East, as well as showing which new seat each ward is in.

Old seat: Londonderry EastTransfer-adjusted Results
DistrictWardElectorate
2015
New SeatUUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
Causeway Coast and GlensAghadowey2,368Glenshane3291155330013884301,229
Causeway Coast and GlensAltahullion2,181Glenshane014539900414127461,131
Causeway Coast and GlensAtlantic2,864Dalriada33499697000262941,486
Causeway Coast and GlensBallykelly2,106Glenshane014038500400122441,091
Causeway Coast and GlensCastlerock2,341Dalriada3261145270013683301,216
Causeway Coast and GlensChurchland2,515Dalriada22124642900396931,304
Causeway Coast and GlensCoolessan2,015Glenshane1411135790016435131,045
Causeway Coast and GlensDrumsurn2,358Glenshane1661326770019341151,224
Causeway Coast and GlensDundooan2,456Dalriada28684598000224801,272
Causeway Coast and GlensDungiven2,170Glenshane014439700412126451,124
Causeway Coast and GlensFeeny2,279Glenshane015141800433133481,183
Causeway Coast and GlensGarvagh2,295Glenshane3191115160013381291,189
Causeway Coast and GlensGreysteel2,940Glenshane019653900558171611,525
Causeway Coast and GlensGreystone2,164Glenshane1521216210017738141,123
Causeway Coast and GlensHopefield2,512Dalriada29387614000229821,305
Causeway Coast and GlensKilrea2,310Glenshane3221135200013482291,200
Causeway Coast and GlensMacosquin2,006Glenshane279974510011671251,039
Causeway Coast and GlensMagilligan2,510Glenshane1761417200020644161,303
Causeway Coast and GlensMountsandel2,480Dalriada21924242300390931,286
Causeway Coast and GlensPortrush and Dunluce1,974Dalriada23068481000180651,024
Causeway Coast and GlensPortstewart2,256Dalriada26378550000205741,170
Causeway Coast and GlensQuarry2,717Dalriada239265464004271041,409
Causeway Coast and GlensRoeside1,990Glenshane1401115710016335131,033
Causeway Coast and GlensUniversity2,693Dalriada237263459004231031,395
Causeway Coast and GlensWaterside2,978Dalriada263291508004681141,545
Causeway Coast and GlensWindy Hall2,736Dalriada241267467004301041,419
Derry and StrabaneClaudy2,329Glenshane941986150017792331,209
Derry and StrabanePark2,380Glenshane6313450500373117421,234
 Total66,923 5,3334,26614,663006,8612,64194934,713

The full details of these calculations are given on the Londonderry East seat details page. Click on "Show workings".

Old seat: Ulster Mid

The table shows the transfer-adjusted results for each ward in the old seat of Ulster Mid, as well as showing which new seat each ward is in.

Old seat: Ulster MidTransfer-adjusted Results
DistrictWardElectorate
2015
New SeatUUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
Mid UlsterArdboe2,484Tyrone North20122813824079466491,500
Mid UlsterBallygawley402Fermanagh and South Tyrone612861508800243
Mid UlsterBallymaguigan2,661Glenshane272183263250863001,606
Mid UlsterBellaghy2,419Glenshane247166240220784001,459
Mid UlsterCastlecaulfield687Fermanagh and South Tyrone104471058015100415
Mid UlsterCastledawson2,442Glenshane250167241220792001,472
Mid UlsterCoagh2,195Tyrone North31213414746058160441,324
Mid UlsterCoalisland North2,391Upper Bann and Blackwater19322013223076364471,442
Mid UlsterCoalisland South2,764Upper Bann and Blackwater22425415327088274541,668
Mid UlsterCookstown East2,117Tyrone North30212814244056058431,277
Mid UlsterCookstown South2,420Tyrone North34514616252064067491,461
Mid UlsterCookstown West2,407Tyrone North34314616152063666491,453
Mid UlsterCoolshinny2,348Glenshane1601843123204771451071,417
Mid UlsterDonaghmore2,483Tyrone North20122813824079466491,500
Mid UlsterDraperstown2,012Glenshane206138200190652001,215
Mid UlsterGlebe2,519Glenshane1711983343405121561151,520
Mid UlsterKillyman409Upper Bann and Blackwater50194550594029247
Mid UlsterKillymeal228Upper Bann and Blackwater28112630332216139
Mid UlsterLissan2,418Glenshane1641903213304911501101,459
Mid UlsterLoughry1,932Tyrone North27611813041051153391,168
Mid UlsterLower Glenshane1,955Glenshane1021479416074743311,180
Mid UlsterMaghera2,519Glenshane13219012220096255401,521
Mid UlsterOaklands2,078Tyrone North29512613944054957421,252
Mid UlsterPomeroy2,567Tyrone North36615517255067870521,548
Mid UlsterStewartstown2,097Tyrone North17019311620066956411,265
Mid UlsterSwatragh2,279Glenshane11917111018087050371,375
Mid UlsterTamlaght O'Crilly2,407Glenshane12618111519092052391,452
Mid UlsterThe Loup2,488Glenshane1691963303405061541131,502
Mid UlsterTobermore2,403Glenshane246165238220779001,450
Mid UlsterTown Parks East2,463Glenshane1671933273305011521121,485
Mid UlsterValley2,424Glenshane12618311620092653391,463
Mid UlsterWashing Bay2,411Upper Bann and Blackwater19522213323076964471,453
 Total67,829 6,3235,0555,463865019,9391,8931,39340,931

The full details of these calculations are given on the Ulster Mid seat details page. Click on "Show workings".

New seat: Glenshane

The new seat of Glenshane is made up of the following wards, with the transfer-adjusted votes shown.

New seat: Glenshane
DistrictWardElectorate
2015
Old Seat UUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
Causeway Coast and GlensAghadowey2,511Londonderry East3291155330013884301,229
Causeway Coast and GlensAltahullion2,190Londonderry East014539900414127461,131
Causeway Coast and GlensBallykelly2,302Londonderry East014038500400122441,091
Causeway Coast and GlensCoolessan2,024Londonderry East1411135790016435131,045
Causeway Coast and GlensDrumsurn2,338Londonderry East1661326770019341151,224
Causeway Coast and GlensDungiven2,385Londonderry East014439700412126451,124
Causeway Coast and GlensFeeny2,276Londonderry East015141800433133481,183
Causeway Coast and GlensGarvagh2,272Londonderry East3191115160013381291,189
Causeway Coast and GlensGreysteel2,876Londonderry East019653900558171611,525
Causeway Coast and GlensGreystone2,290Londonderry East1521216210017738141,123
Causeway Coast and GlensKilrea2,513Londonderry East3221135200013482291,200
Causeway Coast and GlensMacosquin2,373Londonderry East279974510011671251,039
Causeway Coast and GlensMagilligan2,254Londonderry East1761417200020644161,303
Causeway Coast and GlensRoeside2,071Londonderry East1401115710016335131,033
Derry and StrabaneClaudy14Foyle113001107
Derry and StrabaneClaudy2,505Londonderry East942006140017791331,209
Derry and StrabanePark2,477Londonderry East6313450500373117421,234
Mid UlsterBallymaguigan2,595Ulster Mid272183263250863001,606
Mid UlsterBellaghy2,537Ulster Mid247166240220784001,459
Mid UlsterCastledawson2,499Ulster Mid250167241220792001,472
Mid UlsterCoolshinny2,535Ulster Mid1601843123204771451071,417
Mid UlsterDraperstown2,040Ulster Mid206138200190652001,215
Mid UlsterGlebe2,371Ulster Mid1711983343405121561151,520
Mid UlsterLissan2,441Ulster Mid1641903213304911501101,459
Mid UlsterLower Glenshane2,233Ulster Mid1021479416074743311,180
Mid UlsterMaghera2,263Ulster Mid13219012220096255401,521
Mid UlsterSwatragh2,360Ulster Mid11917111018087050371,375
Mid UlsterTamlaght O'Crilly2,449Ulster Mid12618111519092052391,452
Mid UlsterThe Loup2,684Ulster Mid1691963303405061541131,502
Mid UlsterTobermore2,463Ulster Mid246165238220779001,450
Mid UlsterTown Parks East2,303Ulster Mid1671933273305011521121,485
Mid UlsterValley2,389Ulster Mid12618311620092653391,463
 Total73,833 4,8394,81711,811369014,9742,4091,24640,465

And these are the implied results for 2015 for the new seat of Glenshane.


© 2017 Martin Baxter
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