Belfast North West: New Boundaries 2018 Calculation

Belfast North West: Overview

 Projection: SF seat 

Implied MP at 2017: Unknown (changed seat)  (SF)
County/Area: Antrim (Northern Ireland)
Electorate: 71,153
Turnout: 67.5%

 Implied 2017 VotesImplied 2017 Share
SF21,80445.4%
DUP18,93539.4%
MIN3,7387.8%
SDLP2,2874.8%
OTH7631.6%
Green4731.0%
SF Majority2,8696.0%

See overview of other seats in Northern Ireland.

Belfast North West: 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 2017 had the new boundaries for Belfast North West 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 2017. 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 Belfast North West

The old seat(s) needed are:

Old seat: Belfast North

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

Old seat: Belfast NorthTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatUUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
Antrim and NewtownabbeyAbbey1,014Antrim East09447010162487683
Antrim and NewtownabbeyBallyhenry995Antrim West029349011250264669
Antrim and NewtownabbeyBurnthill365Antrim West0111280491101245
Antrim and NewtownabbeyCarnmoney200Antrim West0670025051134
Antrim and NewtownabbeyCarnmoney Hill1,572Antrim East01469201625174111,058
Antrim and NewtownabbeyCollinbridge1,981Belfast North West0596940234985381,335
Antrim and NewtownabbeyGlebe2,092Antrim East0627330245265681,409
Antrim and NewtownabbeyGlengormley2,413Antrim East0728450286076491,625
Antrim and NewtownabbeyHightown1,254Antrim South037439014315335843
Antrim and NewtownabbeyO'Neill2,087Antrim East01991802133599141,406
Antrim and NewtownabbeyRathcoole2,151Antrim East019948021344102151,449
Antrim and NewtownabbeyValley2,171Belfast North West020957022347102151,463
Antrim and NewtownabbeyWhitehouse1,973Antrim East01886902031693141,330
BelfastArdoyne3,611Belfast North West0958120271,350128192,431
BelfastBallysillan3,327Belfast North West0877490251,244118172,240
BelfastBellevue3,425Belfast North West01701,052035921111162,305
BelfastCavehill2,933Belfast North West014590103078995141,974
BelfastChichester Park3,643Belfast North West01811,119037980118172,452
BelfastCliftonville3,629Belfast North West0958160271,357129192,443
BelfastDuncairn4,379Belfast North West02171,3440451,177142212,946
BelfastForth River738Belfast North West01125007187365496
BelfastFortwilliam3,155Belfast North West0156969032848102152,122
BelfastInnisfayle3,459Belfast North West01711,063035931112162,328
BelfastLegoniel3,785Belfast North West0998510291,415134202,548
BelfastNew Lodge3,283Belfast North West0867390251,228116172,211
BelfastShankill1,870Belfast North West02863501847591131,260
BelfastWater Works3,783Belfast North West0998510281,415134202,547
BelfastWoodvale2,960Belfast North West0431,005028751144211,992
 Total68,248 02,05821,245064419,1602,47536245,944

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

Old seat: Belfast West

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

Old seat: Belfast WestTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatUUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
BelfastAndersonstown3,137Belfast South West014188001,557203532,042
BelfastBallygomartin3,887Belfast North West085976009713951032,530
BelfastBallymurphy3,386Belfast South West015295001,680220572,204
BelfastBeechmount3,815Belfast North West0172107001,893248652,485
BelfastCentral177Belfast South West013310046195114
BelfastClonard3,807Belfast North West084956009513871012,479
BelfastCollin Glen3,849Belfast South West0173108001,910249652,505
BelfastDunmurry2,813Belfast South West017993001,411117311,831
BelfastFalls3,431Belfast North West07686200856348912,233
BelfastFalls Park3,153Belfast South West014288001,564204532,051
BelfastForth River2,435Belfast North West05461200608247651,586
BelfastLadybrook3,384Belfast South West0216111001,698141372,203
BelfastLagmore5,089Belfast South West0325167002,553212553,312
BelfastPoleglass4,163Belfast South West0265137002,089174452,710
BelfastShankill2,144Belfast North West04753800535217571,394
BelfastShaw's Road3,416Belfast South West015496001,695221582,224
BelfastStewartstown3,451Belfast South West0220113001,730144382,245
BelfastTurf Lodge3,351Belfast South West015094001,662218572,181
BelfastTwinbrook3,232Belfast South West0206106001,621135352,103
BelfastWoodvale306Belfast North West07770077318200
 Total62,426 02,8615,4550027,1074,1301,07940,632

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

New seat: Belfast North West

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

New seat: Belfast North West
DistrictWardElectorate
2017
Old Seat UUP
Votes
SDLP
Votes
DUP
Votes
UKIP
Votes
Green
Votes
SF
Votes
MIN
Votes
OTH
Votes
Total
Votes
Antrim and NewtownabbeyCollinbridge2,217Belfast North0596940234985381,335
Antrim and NewtownabbeyValley2,201Belfast North020957022347102151,463
BelfastArdoyne3,636Belfast North0958120271,350128192,431
BelfastBallygomartin3,996Belfast West085976009713951032,530
BelfastBallysillan3,325Belfast North0877490251,244118172,240
BelfastBeechmount3,499Belfast West0172107001,893248652,485
BelfastBellevue3,378Belfast North01701,052035921111162,305
BelfastCavehill3,287Belfast North014590103078995141,974
BelfastChichester Park3,679Belfast North01811,119037980118172,452
BelfastCliftonville3,566Belfast North0958160271,357129192,443
BelfastClonard3,667Belfast West084956009513871012,479
BelfastDuncairn3,722Belfast North02171,3440451,177142212,946
BelfastFalls3,239Belfast West07686200856348912,233
BelfastForth River722Belfast North015200021846616483
BelfastForth River2,390Belfast West05066205611217541,599
BelfastFortwilliam3,282Belfast North0156969032848102152,122
BelfastInnisfayle3,691Belfast North01711,063035931112162,328
BelfastLegoniel3,532Belfast North0998510291,415134202,548
BelfastNew Lodge3,302Belfast North0867390251,228116172,211
BelfastShankill2,136Belfast West040627010540165371,419
BelfastShankill1,858Belfast North03554608470143331,235
BelfastWater Works3,748Belfast North0998510281,415134202,547
BelfastWoodvale289Belfast West051020378163207
BelfastWoodvale2,791Belfast North045980025750159261,985
 Total71,153 02,28718,935047321,8043,73876348,000

And these are the implied results for 2017 for the new seat of Belfast North West.


© 2017 Martin Baxter
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