Braintree: New Boundaries 2018 Calculation

Braintree: Overview

Projection: CON seat

Implied MP at 2017:James Cleverly  (CON)
County/Area:Essex (Anglia)
Electorate:78,537
Turnout:69.8%

PartyImplied 2017 VotesImplied 2017 Share
CON34,12462.3%
LAB15,54628.4%
LIB2,3564.3%
UKIP1,5532.8%
Green1,2272.2%
CON Majority18,57833.9%

See overview of other seats in Anglia.



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.

Braintree: Map

Boundary Lines courtesy of Ordnance Survey OpenData © Crown copyright 2015, Map © OpenStreetMap contributors

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 Blackwater7,232Braintree3,4371,4443502121010005,544
BraintreeBocking North4,018Braintree1,5521,038106110570002,863
BraintreeBocking South4,230Braintree1,6671,263142134720003,278
BraintreeBraintree Central and Beckers Green5,905Braintree2,4901,8602181911050004,864
BraintreeBraintree South4,347Braintree1,7371,18010567340003,123
BraintreeBraintree West4,643Braintree1,985878156128680003,215
BraintreeBumpstead2,285Saffron Walden1,1263394757120001,581
BraintreeCoggeshall499Braintree2378214127000352
BraintreeGosfield and Greenstead Green2,211Braintree1,0382733826270001,402
BraintreeGreat Notley and Black Notley5,359Braintree2,822804156139720003,993
BraintreeHalstead St Andrews4,216Braintree1,89783714868830003,033
BraintreeHalstead Trinity4,598Braintree1,7581,224160146390003,327
BraintreeHedingham4,109Braintree1,876656107110310002,780
BraintreeRayne2,203Saffron Walden1,0752645355300001,477
BraintreeSilver End and Cressing1,210Braintree543236424221000884
BraintreeStour Valley North2,271Braintree1,1072643854120001,475
BraintreeStour Valley South2,404Braintree1,12124813257150001,573
BraintreeThe Colnes4,429Braintree2,2526539157620003,115
BraintreeThree Fields4,480Saffron Walden2,147558100107550002,967
BraintreeYeldham2,110Saffron Walden1,0073494759130001,475
 Total72,759 32,87414,4502,2501,83191600052,321

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
BraintreeCoggeshall3,999Braintree1,9707299801140002,911
BraintreeGreat Notley and Black Notley1,792Braintree995294470410001,377
BraintreeHatfield Peverel and Terling4,689Witham and Maldon2,4266789701100003,311
BraintreeKelvedon and Feering4,251Braintree2,04583611501300003,126
BraintreeSilver End and Cressing3,409Braintree1,5957479301360002,571
BraintreeWitham Central4,147Witham and Maldon1,75299728401330003,166
BraintreeWitham North4,759Witham and Maldon1,9181,43525401610003,768
BraintreeWitham South4,260Witham and Maldon1,9951,00022601050003,326
BraintreeWitham West4,801Witham and Maldon2,0471,46221601490003,874
ColchesterBirch and Winstree4,233Essex North East2,3055701800890003,144
ColchesterCopford and West Stanway1,468Essex North East783180690290001,061
ColchesterMarks Tey1,983Essex North East874403890550001,421
ColchesterStanway6,329Essex North East2,7561,18548501720004,598
ColchesterTiptree5,864Essex North East2,8751,02620701200004,228
MaldonGreat Totham2,851Witham and Maldon1,586349500820002,067
MaldonTollesbury1,571Witham and Maldon630384390460001,099
MaldonTolleshunt D'Arcy3,167Witham and Maldon1,5444791320900002,245
MaldonWickham Bishops and Woodham2,830Witham and Maldon1,575270350710001,951
 Total66,403 31,67113,0242,71601,83300049,244

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 Blackwater7,980Braintree3,4371,4443502121010005,544
BraintreeBocking North4,121Braintree1,5521,038106110570002,863
BraintreeBocking South4,719Braintree1,6671,263142134720003,278
BraintreeBraintree Central and Beckers Green7,002Braintree2,4901,8602181911050004,864
BraintreeBraintree South4,494Braintree1,7371,18010567340003,123
BraintreeBraintree West4,626Braintree1,985878156128680003,215
BraintreeCoggeshall507Braintree2378214127000352
BraintreeCoggeshall4,086Witham1,9707299801140002,911
BraintreeGosfield and Greenstead Green2,018Braintree1,0382733826270001,402
BraintreeGreat Notley and Black Notley5,747Braintree2,822804156139720003,993
BraintreeGreat Notley and Black Notley1,934Witham995294470410001,377
BraintreeHalstead St Andrews4,367Braintree1,89783714868830003,033
BraintreeHalstead Trinity4,790Braintree1,7581,224160146390003,327
BraintreeHedingham4,003Braintree1,876656107110310002,780
BraintreeKelvedon and Feering4,389Witham2,04583611501300003,126
BraintreeSilver End and Cressing1,273Braintree543236424221000884
BraintreeSilver End and Cressing3,609Witham1,5957479301360002,571
BraintreeStour Valley North2,124Braintree1,1072643854120001,475
BraintreeStour Valley South2,264Braintree1,12124813257150001,573
BraintreeThe Colnes4,484Braintree2,2526539157620003,115
 Total78,537 34,12415,5462,3561,5531,22700054,806

And these are the implied results for 2017 for the new seat of Braintree. Please note that the wards used are those of 2015 in order to be consistent with those used by the Boundary Commissions.


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