Braintree: New Boundaries 2018 Calculation

Braintree: Overview

 Projection: CON seat 

Implied MP at 2017: James Cleverly  (CON)
County/Area: Essex (Anglia)
Electorate: 75,132
Turnout: 72.9%

 Implied 2017 VotesImplied 2017 Share
CON33,96662.0%
LAB15,65828.6%
LIB2,2854.2%
UKIP1,5572.8%
Green1,3402.4%
CON Majority18,30833.4%

See overview of other seats in Anglia.

Braintree : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Braintree constituency, the 'Anglia' 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.

IndicatorSeatAngliaAll GB
Party WinnerCONCONCON
Economic Position12° Right8° Right
National Position15° Nat10° Nat1° Int
EU Leave %61%57%52%
British Identity30%27%29%
Good Health50%47%48%
UK Born94%89%88%
Good Education47%37%39%
Good Job62%53%51%
High SEC66%53%51%
Average Age52.149.448.5
ABC1 Class67%55%53%

Braintree ranks #115 for "Leave", #71 for "Right" and #41 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

Braintree: 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 Braintree 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 Braintree

The old seat(s) needed are:

Old seat: Braintree

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

Old seat: BraintreeTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
BraintreeBocking Blackwater7,980Braintree3,5011,438315224650005,543
BraintreeBocking North4,121Braintree1,5111,075104130440002,864
BraintreeBocking South4,719Braintree1,5661,274139234650003,278
BraintreeBraintree Central and Beckers Green7,002Braintree2,5361,8671811741070004,865
BraintreeBraintree South4,494Braintree1,7091,256559560003,121
BraintreeBraintree West4,626Braintree2,052881109122500003,214
BraintreeBumpstead2,276Saffron Walden1,143334415950001,582
BraintreeCoggeshall507Braintree2368712810000353
BraintreeGosfield and Greenstead Green2,018Braintree1,0372694011450001,402
BraintreeGreat Notley and Black Notley5,747Braintree2,9378438580480003,993
BraintreeHalstead St Andrews4,367Braintree1,94079320234630003,032
BraintreeHalstead Trinity4,790Braintree1,7321,164224167410003,328
BraintreeHedingham4,003Braintree1,844619157127340002,781
BraintreeRayne2,127Saffron Walden1,0682487262270001,477
BraintreeSilver End and Cressing1,273Braintree464246544477000885
BraintreeStour Valley North2,124Braintree1,0962654151220001,475
BraintreeStour Valley South2,264Braintree1,10425216034230001,573
BraintreeThe Colnes4,484Braintree2,205652132221040003,115
BraintreeThree Fields4,272Saffron Walden2,1945488374680002,967
BraintreeYeldham2,123Saffron Walden9953404482130001,474
 Total75,317 32,87014,4512,2501,83491700052,322

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

Old seat: Witham

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

Old seat: WithamTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
BraintreeCoggeshall4,086Braintree1,9607577901140002,910
BraintreeGreat Notley and Black Notley1,934Braintree1,021303260280001,378
BraintreeHatfield Peverel and Terling4,650Witham and Maldon2,421760540770003,312
BraintreeKelvedon and Feering4,389Braintree2,1177949501200003,126
BraintreeSilver End and Cressing3,609Braintree1,3988237502740002,570
BraintreeWitham Central4,446Witham and Maldon1,88791124601210003,165
BraintreeWitham North5,289Witham and Maldon1,9491,43621601670003,768
BraintreeWitham South4,669Witham and Maldon2,0031,0491830910003,326
BraintreeWitham West5,438Witham and Maldon2,1501,37522001280003,873
ColchesterBirch and Winstree4,415Essex North East2,2266611810770003,145
ColchesterCopford and West Stanway1,489Essex North East798182540270001,061
ColchesterMarks Tey1,994Essex North East853411870690001,420
ColchesterStanway6,457Essex North East2,6531,07673701330004,599
ColchesterTiptree5,937Essex North East2,7831,12221501080004,228
MaldonGreat Totham2,901Witham and Maldon1,684289280660002,067
MaldonTollesbury1,543Witham and Maldon606369740500001,099
MaldonTolleshunt D'Arcy3,152Witham and Maldon1,52450011801030002,245
MaldonWickham Bishops and Woodham2,739Witham and Maldon1,637205280800001,950
 Total69,137 31,67013,0232,71601,83300049,242

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

New seat: Braintree

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

New seat: Braintree
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
BraintreeBocking Blackwater7,232Braintree3,5011,438315224650005,543
BraintreeBocking North4,018Braintree1,5111,075104130440002,864
BraintreeBocking South4,230Braintree1,5661,274139234650003,278
BraintreeBraintree Central and Beckers Green5,905Braintree2,5361,8671811741070004,865
BraintreeBraintree South4,347Braintree1,7091,256559560003,121
BraintreeBraintree West4,643Braintree2,052881109122500003,214
BraintreeCoggeshall497Braintree2439310114000361
BraintreeCoggeshall4,001Witham1,9537518171100002,902
BraintreeGosfield and Greenstead Green2,211Braintree1,0372694011450001,402
BraintreeGreat Notley and Black Notley5,350Braintree2,9618578360570004,018
BraintreeGreat Notley and Black Notley1,801Witham9972892820190001,353
BraintreeHalstead St Andrews4,216Braintree1,94079320234630003,032
BraintreeHalstead Trinity4,598Braintree1,7321,164224167410003,328
BraintreeHedingham4,109Braintree1,844619157127340002,781
BraintreeKelvedon and Feering4,251Witham2,1177949501200003,126
BraintreeSilver End and Cressing1,204Braintree485279341191000900
BraintreeSilver End and Cressing3,415Witham1,37779095332600002,555
BraintreeStour Valley North2,271Braintree1,0962654151220001,475
BraintreeStour Valley South2,404Braintree1,10425216034230001,573
BraintreeThe Colnes4,429Braintree2,205652132221040003,115
 Total75,132 33,96615,6582,2851,5571,34000054,806

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


© 2017 Martin Baxter
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