Blaenau Gwent: New Boundaries 2018 Calculation

Blaenau Gwent: Overview

 Projection: LAB seat 

Implied MP at 2017: Nick Smith  (LAB)
County/Area: Gwent (Wales)
Electorate: 75,664
Turnout: 66.0%

 Implied 2017 VotesImplied 2017 Share
LAB28,19356.4%
CON10,17020.4%
Plaid8,46316.9%
UKIP1,8383.7%
MIN6671.3%
LIB6281.3%
LAB Majority18,02336.1%

See overview of other seats in Wales.

Blaenau Gwent : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Blaenau Gwent 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 Position18° Left10° Left
National Position1° Nat3° Int1° Int
EU Leave %61%53%52%
British Identity21%26%29%
Good Health43%47%48%
UK Born98%95%88%
Good Education26%36%39%
Good Job38%46%51%
High SEC35%46%51%
Average Age49.349.648.5
ABC1 Class35%47%53%

Blaenau Gwent ranks #118 for "Leave", #571 for "Right" and #341 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

Blaenau Gwent: 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 Blaenau Gwent 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 Blaenau Gwent

The old seat(s) needed are:

Old seat: Blaenau Gwent

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

Old seat: Blaenau GwentTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
Blaenau GwentAbertillery3,234Blaenau Gwent388966369105075602,044
Blaenau GwentBadminton2,287Blaenau Gwent222805235403182401,446
Blaenau GwentBeaufort2,809Blaenau Gwent340835156704694901,775
Blaenau GwentBlaina3,481Blaenau Gwent3441,158385505545102,200
Blaenau GwentBrynmawr4,050Blaenau Gwent4861,177269307166202,560
Blaenau GwentCwm3,247Blaenau Gwent2661,32486803493802,053
Blaenau GwentCwmtillery3,466Blaenau Gwent3331,288104304694902,192
Blaenau GwentEbbw Vale North3,353Blaenau Gwent2781,288117904184602,120
Blaenau GwentEbbw Vale South3,029Blaenau Gwent3101,141214603593801,915
Blaenau GwentGeorgetown2,482Blaenau Gwent1511,129262502142401,569
Blaenau GwentLlanhilleth3,518Blaenau Gwent3531,332108004024602,223
Blaenau GwentNantyglo3,399Blaenau Gwent2691,35094204324602,148
Blaenau GwentRassau2,406Blaenau Gwent262767277003583701,521
Blaenau GwentSirhowy4,147Blaenau Gwent3171,76896004333502,622
Blaenau GwentSix Bells1,866Blaenau Gwent186598153603123201,179
Blaenau GwentTredegar Central and West4,453Blaenau Gwent2781,85996605703402,816
 Total51,227 4,78318,78529397506,880667032,383

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

Old seat: Islwyn

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

Old seat: IslwynTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
CaerphillyAberbargoed2,712Merthyr Tydfil and Rhymney921,47628200124001,740
CaerphillyAbercarn3,991Caerphilly5631,72041640172002,560
CaerphillyArgoed2,063Blaenau Gwent29480240720117001,325
CaerphillyBlackwood6,327Blaenau Gwent1,4262,089852030256004,059
CaerphillyCefn Fforest2,915Blaenau Gwent3401,3432074093001,870
CaerphillyCrosskeys2,469Caerphilly4139685095058001,584
CaerphillyCrumlin4,355Blaenau Gwent1,0021,205491740363002,793
CaerphillyMaesycwmmer1,657Caerphilly161831534032001,063
CaerphillyNewbridge4,852Blaenau Gwent1,1181,359671830386003,113
CaerphillyPengam2,868Blaenau Gwent4381,11738770171001,841
CaerphillyPenmaen4,014Blaenau Gwent7691,49336800197002,575
CaerphillyPontllanfraith6,399Caerphilly1,0862,493451570325004,106
CaerphillyRisca East4,831Caerphilly7401,965771430175003,100
CaerphillyRisca West3,880Caerphilly9421,21185169081002,488
CaerphillyYnysddu2,922Caerphilly4421,16819590188001,876
 Total56,255 9,82621,2406851,60402,7380036,093

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

New seat: Blaenau Gwent

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

New seat: Blaenau Gwent
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
Plaid
Votes
MIN
Votes
OTH
Votes
Total
Votes
Blaenau GwentAbertillery3,095Blaenau Gwent388966369105075602,044
Blaenau GwentBadminton2,428Blaenau Gwent222805235403182401,446
Blaenau GwentBeaufort2,768Blaenau Gwent340835156704694901,775
Blaenau GwentBlaina3,351Blaenau Gwent3441,158385505545102,200
Blaenau GwentBrynmawr3,826Blaenau Gwent4861,177269307166202,560
Blaenau GwentCwm3,168Blaenau Gwent2661,32486803493802,053
Blaenau GwentCwmtillery3,358Blaenau Gwent3331,288104304694902,192
Blaenau GwentEbbw Vale North3,249Blaenau Gwent2781,288117904184602,120
Blaenau GwentEbbw Vale South2,905Blaenau Gwent3101,141214603593801,915
Blaenau GwentGeorgetown2,942Blaenau Gwent1511,129262502142401,569
Blaenau GwentLlanhilleth3,324Blaenau Gwent3531,332108004024602,223
Blaenau GwentNantyglo3,187Blaenau Gwent2691,35094204324602,148
Blaenau GwentRassau2,386Blaenau Gwent262767277003583701,521
Blaenau GwentSirhowy4,125Blaenau Gwent3171,76896004333502,622
Blaenau GwentSix Bells1,702Blaenau Gwent186598153603123201,179
Blaenau GwentTredegar Central and West3,847Blaenau Gwent2781,85996605703402,816
CaerphillyArgoed1,910Islwyn29480240720117001,325
CaerphillyBlackwood5,947Islwyn1,4262,089852030256004,059
CaerphillyCefn Fforest2,765Islwyn3401,3432074093001,870
CaerphillyCrumlin4,195Islwyn1,0021,205491740363002,793
CaerphillyNewbridge4,611Islwyn1,1181,359671830386003,113
CaerphillyPengam2,571Islwyn4381,11738770171001,841
CaerphillyPenmaen4,004Islwyn7691,49336800197002,575
 Total75,664 10,17028,1936281,83808,463667049,959

And these are the implied results for 2017 for the new seat of Blaenau Gwent.


© 2017 Martin Baxter
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