Chippenham and North Wiltshire: New Boundaries 2018 Calculation

Chippenham and North Wiltshire: Overview

 Projection: CON seat 

Implied MP at 2017: James Gray  (CON)
County/Area: Wiltshire (South West)
Electorate: 79,203
Turnout: 75.0%

 Implied 2017 VotesImplied 2017 Share
CON Majority22,66738.1%

See overview of other seats in South West.

Chippenham and North Wiltshire : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Chippenham and North Wiltshire constituency, the 'South West' area and nation.

The political measures include the three axes: Economic (Left/Right), National (Global/National) and Social (Liberal/Conservative). (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.

IndicatorSeatSouth WestAll GB
Economic Position16° Right8° Right
National Position2° Nat4° Nat
Social Position
TribeKind Yuppies
EU Leave %49%53%52%
British Identity31%27%29%
Good Health52%47%48%
UK Born93%92%88%
Good Education45%40%39%
Good Job58%50%51%
High SEC61%52%51%
Average Age50.050.548.5
ABC1 Class63%54%53%

Chippenham and North Wiltshire ranks #400 for "Leave", #34 for "Right", #314 for "National" and #397 for "Social" 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 GlobalGlobalCentristNationalVery Nat
Social PositionVery LibLiberalModerateConservativeVery Cons
EU Leave %Very RemainRemainBalancedLeaveVery Leave
CensusVery LowLowMediumHighVery High

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

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° Global and 100° National, estimated by Electoral Calculus from political and demographic data.
Social PositionSocial position between 100° Liberal and 100° Conservative, estimated by Electoral Calculus from political and demographic data.
TribeTribe group dominant in the area. Can be: Strong Left, Traditionalists, Progressives, Centrists, Somewheres, Kind Young Capitalists, or Strong Right. See details.
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

Chippenham and North Wiltshire: Map

Boundary Lines courtesy of Ordnance Survey OpenData © Crown copyright 2015


This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Chippenham and North Wiltshire 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 Chippenham and North Wiltshire

The old seat(s) needed are:

Old seat: Chippenham

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

Old seat: ChippenhamTransfer-adjusted Results
New SeatCON
WiltshireBradford-on-Avon North3,735Trowbridge and West Wiltshire1,357477958000002,792
WiltshireBradford-on-Avon South3,750Trowbridge and West Wiltshire1,308538957000002,803
WiltshireChippenham Cepen Park and Derriads3,513Chippenham and North Wiltshire1,668556402000002,626
WiltshireChippenham Cepen Park and Redlands3,875Chippenham and North Wiltshire1,791677428000002,896
WiltshireChippenham Hardenhuish3,801Chippenham and North Wiltshire1,436574831000002,841
WiltshireChippenham Hardens and England3,419Chippenham and North Wiltshire1,206582768000002,556
WiltshireChippenham Lowden and Rowden3,702Chippenham and North Wiltshire1,343595829000002,767
WiltshireChippenham Monkton2,964Chippenham and North Wiltshire1,029387800000002,216
WiltshireChippenham Pewsham3,628Chippenham and North Wiltshire1,283482948000002,713
WiltshireChippenham Queens and Sheldon3,587Chippenham and North Wiltshire1,305609768000002,682
WiltshireCorsham Pickwick3,943Trowbridge and West Wiltshire1,647842459000002,948
WiltshireCorsham Town3,727Trowbridge and West Wiltshire1,608438740000002,786
WiltshireCorsham Without and Box Hill2,548Trowbridge and West Wiltshire1,312324268000001,904
WiltshireHilperton3,877Trowbridge and West Wiltshire1,854570474000002,898
WiltshireHolt and Staverton3,585Trowbridge and West Wiltshire1,421385873000002,679
WiltshireMelksham Central4,010Trowbridge and West Wiltshire1,480721796000002,997
WiltshireMelksham North3,675Trowbridge and West Wiltshire1,402582763000002,747
WiltshireMelksham South3,989Trowbridge and West Wiltshire1,4155351,032000002,982
WiltshireMelksham Without North3,505Trowbridge and West Wiltshire1,778436405000002,619
WiltshireMelksham Without South3,956Trowbridge and West Wiltshire1,954554450000002,958
WiltshireSummerham and Seend747Trowbridge and West Wiltshire422667000000558
WiltshireWinsley and Westwood2,899Trowbridge and West Wiltshire1,246305617000002,168
 Total76,435 31,26511,23514,6360000057,136

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

Old seat: Wiltshire North

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

Old seat: Wiltshire NorthTransfer-adjusted Results
New SeatCON
WiltshireBox and Colerne4,211Chippenham and North Wiltshire1,776503749286600453,167
WiltshireBrinkworth3,608Chippenham and North Wiltshire1,884392317445500212,713
WiltshireBy Brook3,642Chippenham and North Wiltshire1,960368306425200102,738
WiltshireCalne Central3,364Devizes and East Wiltshire1,156578659586300172,531
WiltshireCalne Chilvester and Abberd4,096Devizes and East Wiltshire1,623727575657600143,080
WiltshireCalne North3,862Devizes and East Wiltshire1,328647780606800232,906
WiltshireCalne Rural3,525Devizes and East Wiltshire1,831397273515400452,651
WiltshireCalne South and Cherhill3,800Devizes and East Wiltshire1,653491566566700262,859
WiltshireChippenham Cepen Park and Redlands64Chippenham and North Wiltshire271361100048
WiltshireChippenham Hardens and England21Chippenham and North Wiltshire7440000015
WiltshireCorsham Pickwick219Trowbridge and West Wiltshire82522334001165
WiltshireCorsham Without and Box Hill1,828Trowbridge and West Wiltshire86827816824310061,375
WiltshireCricklade and Latton4,020Chippenham and North Wiltshire1,654500762276600143,023
WiltshireKington3,975Chippenham and North Wiltshire2,081423363486100132,989
WiltshireLyneham4,412Chippenham and North Wiltshire2,273535380595700143,318
WiltshireMalmesbury4,364Chippenham and North Wiltshire1,592650877598000243,282
WiltshireMinety3,827Chippenham and North Wiltshire1,996437316515800202,878
WiltshirePurton3,437Chippenham and North Wiltshire1,848361272254200372,585
WiltshireSherston3,836Chippenham and North Wiltshire2,043433328215000102,885
WiltshireRoyal Wootton Bassett East3,562Chippenham and North Wiltshire1,768416408255100112,679
WiltshireRoyal Wootton Bassett North3,583Chippenham and North Wiltshire1,410589563596300122,696
WiltshireRoyal Wootton Bassett South4,152Chippenham and North Wiltshire1,538604826667400143,122
 Total71,408 32,3989,3989,5218721,1390037753,705

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

New seat: Chippenham and North Wiltshire

The new seat of Chippenham and North Wiltshire is made up of the following wards, with the transfer-adjusted votes shown.

New seat: Chippenham and North Wiltshire
Old Seat CON
WiltshireBox and Colerne4,211Wiltshire North1,776503749286600453,167
WiltshireBrinkworth3,608Wiltshire North1,884392317445500212,713
WiltshireBy Brook3,642Wiltshire North1,960368306425200102,738
WiltshireChippenham Cepen Park and Derriads3,513Chippenham1,668556402000002,626
WiltshireChippenham Cepen Park and Redlands3,875Chippenham1,791677428000002,896
WiltshireChippenham Cepen Park and Redlands64Wiltshire North271361100048
WiltshireChippenham Hardenhuish3,801Chippenham1,436574831000002,841
WiltshireChippenham Hardens and England3,419Chippenham1,206582768000002,556
WiltshireChippenham Hardens and England21Wiltshire North7440000015
WiltshireChippenham Lowden and Rowden3,702Chippenham1,343595829000002,767
WiltshireChippenham Monkton2,964Chippenham1,029387800000002,216
WiltshireChippenham Pewsham3,628Chippenham1,283482948000002,713
WiltshireChippenham Queens and Sheldon3,587Chippenham1,305609768000002,682
WiltshireCricklade and Latton4,020Wiltshire North1,654500762276600143,023
WiltshireKington3,975Wiltshire North2,081423363486100132,989
WiltshireLyneham4,412Wiltshire North2,273535380595700143,318
WiltshireMalmesbury4,364Wiltshire North1,592650877598000243,282
WiltshireMinety3,827Wiltshire North1,996437316515800202,878
WiltshirePurton3,437Wiltshire North1,848361272254200372,585
WiltshireRoyal Wootton Bassett East3,562Wiltshire North1,768416408255100112,679
WiltshireRoyal Wootton Bassett North3,583Wiltshire North1,410589563596300122,696
WiltshireRoyal Wootton Bassett South4,152Wiltshire North1,538604826667400143,122
WiltshireSherston3,836Wiltshire North2,043433328215000102,885
 Total79,203 34,91810,69012,2515557760024559,435

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

© 2019 Electoral Calculus Ltd
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