Bridgend and Vale of Glamorgan West: New Boundaries 2018 Calculation

Bridgend and Vale of Glamorgan West: Overview

 Projection: LAB seat 

Implied MP at 2017: Madeleine Moon  (LAB)
County/Area: Mid Glamorgan (Wales)
Electorate: 78,764
Turnout: 70.1%

 Implied 2017 VotesImplied 2017 Share
LAB26,56748.1%
CON23,57442.7%
Plaid2,1894.0%
LIB1,0832.0%
UKIP9751.8%
OTH7411.3%
Green890.2%
LAB Majority2,9935.4%

See overview of other seats in Wales.

Bridgend and Vale of Glamorgan West : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Bridgend and Vale of Glamorgan West constituency, the 'Wales' area and nation.

The political measures include the Left/Right and International/National axes (what does this mean).

The demographic measures are from the 2011 Census and include categories relating to national identity, economic activity, health and education. These categories are those which have the most relevance to political attitudes.

IndicatorSeatWalesAll GB
Party WinnerLABLABCON
Economic Position4° Left10° Left
National Position1° Int3° Int1° Int
EU Leave %52%53%52%
British Identity28%26%29%
Good Health48%47%48%
UK Born95%95%88%
Good Education39%36%39%
Good Job52%46%51%
High SEC52%46%51%
Average Age49.849.648.5
ABC1 Class52%47%53%

Bridgend and Vale of Glamorgan West ranks #325 for "Leave", #413 for "Right" and #395 for "National" out of 600 new seats.

Indicators: Legend and Descriptions

Indicators : Legend and Descriptions

The colour scheme used in the table above is explained in the legend table below. The eight census indicators (British Identity, Good Health, UK Born, Good Education, Good Job, High SEC, Average Age and AB1 Class) all use the same 'Census' colour scheme indicating whether the area's level is above or below the national average.

TopicCat 1Cat 2Cat 3Cat 4Cat 5
Economic PositionVery LeftLeftCentristRightVery Right
National PositionVery IntInternationalCentristNationalVery Nat
EU Leave %Very RemainRemainBalancedLeaveVery Leave
CensusVery LowLowMediumHighVery High

Indicator definitions are given in terms of political data definitions or census categories:

IndicatorCensus
Question
Definition / Included Census Categories
Party WinnerArea party winner : actual election result or projected by Electoral Calculus
Economic PositionEconomic position between 100° Left and 100° Right, estimated by Electoral Calculus from political and demographic data.
National PositionNational position between 100° International and 100° National, estimated by Electoral Calculus from political and demographic data.
EU Leave %EU Referendum vote share for 'Leave' : actual result or estimate
British IdentityNational Identity (KS202)Those answering British, British-Other, or Scottish-British
Good HealthHealth (KS301)Those answering 'Very Good Health'
UK BornCountry of Birth (QS203)Those answering England, Northern Ireland, Scotland, Wales, GB Other, or UK Other
Good EducationHighest level of Qualification (QS501)Level 3 (A-level equivalent) or Level 4+ (degree equivalent)
Good JobOccupation (QS606)Occupation codes 1xx to 4xx (Managers, Professionals, Associates, and office workers)
High SECNS-SeC of Household Reference Person (QS609)National Statistics Socio-economic Classification from 1 to 4 (higher managers and professionals, lower managers and professionals, intermediate occupations, small employers and self-employed).
Average AgeAge (QS103)Average age of adults (18 years and above)
ABC1 ClassApproximated Social Grade (QS611)Approximated social grades A, B and C1

Bridgend and Vale of Glamorgan 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 Bridgend and Vale of Glamorgan 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 Bridgend and Vale of Glamorgan West

The old seat(s) needed are:

Old seat: Bridgend

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

Old seat: BridgendTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
BridgendCefn Glas1,093Bridgend and Vale of Glamorgan West2664292015020010760
BridgendCoity1,625Bridgend and Vale of Glamorgan West59540052260240331,130
BridgendCornelly5,491Bridgend and Vale of Glamorgan West1,3882,14638740900843,820
BridgendLitchard1,673Bridgend and Vale of Glamorgan West5385571319029081,164
BridgendLlangewydd and Brynhyfryd2,094Bridgend and Vale of Glamorgan West44386047260580211,455
BridgendMorfa3,638Bridgend and Vale of Glamorgan West7931,392374902060532,530
BridgendNewcastle4,167Bridgend and Vale of Glamorgan West1,1681,55633460720242,899
BridgendNewton2,814Bridgend and Vale of Glamorgan West1,097661173201300201,957
BridgendNottage2,629Bridgend and Vale of Glamorgan West92675557360410141,829
BridgendPendre1,518Bridgend and Vale of Glamorgan West3695573220070081,056
BridgendPen-y-fai1,889Bridgend and Vale of Glamorgan West66255711220390221,313
BridgendPorthcawl East Central2,636Bridgend and Vale of Glamorgan West691919193501340341,832
BridgendPorthcawl West Central2,686Bridgend and Vale of Glamorgan West87083627370460531,869
BridgendPyle5,776Bridgend and Vale of Glamorgan West1,2052,477997201050604,018
BridgendRest Bay1,702Bridgend and Vale of Glamorgan West72237427210210191,184
BridgendBrackla9,050Bridgend and Vale of Glamorgan West2,0953,43916210804000906,294
BridgendBryntirion, Laleston and Merthyrmawr6,879Bridgend and Vale of Glamorgan West1,9702,3951617701490344,786
BridgendCoychurch Lower1,074Bridgend and Vale of Glamorgan West383316416012017748
BridgendOldcastle3,750Bridgend and Vale of Glamorgan West1,0331,287624801370422,609
 Total62,184 17,21421,91391877901,783064643,253

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

Old seat: Ogmore

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

Old seat: OgmoreTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
BridgendAberkenfig1,538Ogmore and Aberavon28949417380172001,010
BridgendBettws (Ogmore)1,689Ogmore and Aberavon215815833039001,110
BridgendBlackmill1,882Ogmore and Aberavon2798571236053001,237
BridgendBlaengarw1,357Ogmore and Aberavon187619172904000892
BridgendBryncethin1,012Ogmore and Aberavon162413262004400665
BridgendBryncoch1,703Ogmore and Aberavon2647383434049001,119
BridgendCaerau5,308Ogmore and Aberavon7262,492291210117003,485
BridgendCefn Cribwr1,126Bridgend and Vale of Glamorgan West18648352304200739
BridgendFelindre2,105Ogmore and Aberavon4028225143064001,382
BridgendHendre3,134Ogmore and Aberavon6301,2432164098002,056
BridgendLlangeinor943Ogmore and Aberavon15141841902800620
BridgendLlangynwyd2,312Ogmore and Aberavon44578816540214001,517
BridgendMaesteg East3,622Ogmore and Aberavon5641,50618840206002,378
BridgendMaesteg West4,402Ogmore and Aberavon6841,700901000316002,890
BridgendNant-y-moel1,776Ogmore and Aberavon2977561942053001,167
BridgendOgmore Vale2,367Ogmore and Aberavon3949823654088001,554
BridgendPenprysg2,383Ogmore and Aberavon44394924490100001,565
BridgendPontycymmer1,896Ogmore and Aberavon2568761942052001,245
BridgendSarn1,854Ogmore and Aberavon2708401638054001,218
BridgendYnysawdre2,561Ogmore and Aberavon46093521570209001,682
Rhondda Cynon TafBrynna2,901Ogmore and Aberavon5221,07618610229001,906
Rhondda Cynon TafGilfach Goch2,625Ogmore and Aberavon3661,1964852062001,724
Rhondda Cynon TafLlanharan2,632Ogmore and Aberavon49896615550194001,728
Rhondda Cynon TafLlanharry2,813Rhondda and Llantrisant4951,06924580201001,847
Rhondda Cynon TafPont-y-clun707Rhondda and Llantrisant16719162907100464
Rhondda Cynon TafTalbot Green12Rhondda and Llantrisant240001007
 Total56,660 9,35423,2285941,23502,7960037,207

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

Old seat: Vale of Glamorgan

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

Old seat: Vale of GlamorganTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
Vale of GlamorganBaruc4,852Vale of Glamorgan East1,6711,3759977382390253,524
Vale of GlamorganButtrills4,930Vale of Glamorgan East1,2321,9599264341820193,582
Vale of GlamorganCadoc7,581Vale of Glamorgan East1,8913,06111497382780285,507
Vale of GlamorganCastleland3,637Vale of Glamorgan East8221,555654427124062,643
Vale of GlamorganCourt3,636Vale of Glamorgan East8481,5316150251110142,640
Vale of GlamorganCowbridge4,685Vale of Glamorgan East2,2069364639211310233,402
Vale of GlamorganDyfan3,879Vale of Glamorgan East1,1981,375534422118072,817
Vale of GlamorganGibbonsdown4,379Vale of Glamorgan East9781,9624948241030163,180
Vale of GlamorganIlltyd6,094Vale of Glamorgan East1,9232,00810781372410294,426
Vale of GlamorganLlandow / Ewenny2,018Bridgend and Vale of Glamorgan West9603821819876031,466
Vale of GlamorganLlantwit Major8,011Bridgend and Vale of Glamorgan West2,9912,358110107451600485,819
Vale of GlamorganPeterston-super-Ely1,702Vale of Glamorgan East867320710423051,236
Vale of GlamorganRhoose5,250Vale of Glamorgan East2,2851,2805052201060223,815
Vale of GlamorganSt Athan3,407Bridgend and Vale of Glamorgan West1,318968183211920362,475
Vale of GlamorganSt Bride's Major2,018Bridgend and Vale of Glamorgan West90546314152536081,466
Vale of GlamorganWenvoe1,943Vale of Glamorgan East9713801213628021,412
Vale of GlamorganDinas Powys5,937Vale of Glamorgan East2,4331,39910379362490124,311
 Total73,959 25,49923,3121,0188714212,297030353,721

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

New seat: Bridgend and Vale of Glamorgan West

The new seat of Bridgend and Vale of Glamorgan West is made up of the following wards, with the transfer-adjusted votes shown.

New seat: Bridgend and Vale of Glamorgan West
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
BridgendBrackla9,050Bridgend2,0953,43916210804000906,294
BridgendBryntirion, Laleston and Merthyrmawr6,879Bridgend1,9702,3951617701490344,786
BridgendCefn Cribwr1,126Ogmore18648352304200739
BridgendCefn Glas1,093Bridgend2664292015020010760
BridgendCoity1,625Bridgend59540052260240331,130
BridgendCornelly5,491Bridgend1,3882,14638740900843,820
BridgendCoychurch Lower1,074Bridgend383316416012017748
BridgendLitchard1,673Bridgend5385571319029081,164
BridgendLlangewydd and Brynhyfryd2,094Bridgend44386047260580211,455
BridgendMorfa3,638Bridgend7931,392374902060532,530
BridgendNewcastle4,167Bridgend1,1681,55633460720242,899
BridgendNewton2,814Bridgend1,097661173201300201,957
BridgendNottage2,629Bridgend92675557360410141,829
BridgendOldcastle3,750Bridgend1,0331,287624801370422,609
BridgendPen-y-fai1,889Bridgend66255711220390221,313
BridgendPendre1,518Bridgend3695573220070081,056
BridgendPorthcawl East Central2,636Bridgend691919193501340341,832
BridgendPorthcawl West Central2,686Bridgend87083627370460531,869
BridgendPyle5,776Bridgend1,2052,477997201050604,018
BridgendRest Bay1,702Bridgend72237427210210191,184
Vale of GlamorganLlandow / Ewenny2,018Vale of Glamorgan9603821819876031,466
Vale of GlamorganLlantwit Major8,011Vale of Glamorgan2,9912,358110107451600485,819
Vale of GlamorganSt Athan3,407Vale of Glamorgan1,318968183211920362,475
Vale of GlamorganSt Bride's Major2,018Vale of Glamorgan90546314152536081,466
 Total78,764 23,57426,5671,083975892,189074155,218

And these are the implied results for 2017 for the new seat of Bridgend and Vale of Glamorgan West.


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