Christchurch: New Boundaries 2018 Calculation

Christchurch: Overview

 Projection: CON seat 

Implied MP at 2017: Christopher Chope  (CON)
County/Area: Dorset (South West)
Electorate: 81,514
Turnout: 72.1%

 Implied 2017 VotesImplied 2017 Share
CON41,12869.9%
LAB11,36319.3%
LIB4,8438.2%
Green1,4722.5%
CON Majority29,76550.6%

See overview of other seats in South West.

Christchurch : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Christchurch constituency, the 'South West' 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.

IndicatorSeatSouth WestAll GB
Party WinnerCONCONCON
Economic Position9° Right1° Right
National Position11° Nat1° Nat1° Int
EU Leave %59%53%52%
British Identity26%27%29%
Good Health42%47%48%
UK Born95%92%88%
Good Education36%40%39%
Good Job54%50%51%
High SEC58%52%51%
Average Age56.650.548.5
ABC1 Class58%54%53%

Christchurch ranks #159 for "Leave", #117 for "Right" and #105 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

Christchurch: 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 Christchurch 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 Christchurch

The old seat(s) needed are:

Old seat: Christchurch

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

Old seat: ChristchurchTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
ChristchurchBurton and Winkton3,500Christchurch1,7105711960430002,520
ChristchurchGrange4,099Christchurch1,4671,09726001270002,951
ChristchurchHighcliffe2,907Christchurch1,5413791420310002,093
ChristchurchJumpers3,673Christchurch1,62164524601320002,644
ChristchurchMudeford and Friars Cliff4,195Christchurch2,2065532130480003,020
ChristchurchNorth Highcliffe and Walkford3,058Christchurch1,6104001550370002,202
ChristchurchPortfield3,765Christchurch1,5958282350520002,710
ChristchurchPurewell and Stanpit3,602Christchurch1,62161323101280002,593
ChristchurchSt Catherine's and Hurn3,126Christchurch1,6443961730380002,251
ChristchurchTown Centre3,536Christchurch1,65951624001310002,546
ChristchurchWest Highcliffe4,706Christchurch2,4426302580580003,388
East DorsetAmeysford2,444Christchurch1,2992901420290001,760
East DorsetColehill East1,063Dorset Mid476120155014000765
East DorsetFerndown Central7,077Christchurch3,7499053610800005,095
East DorsetHampreston and Longham2,914Christchurch1,6223041430290002,098
East DorsetParley4,534Christchurch2,40247724901370003,265
East DorsetSt Leonards5,770Christchurch3,2555782620590004,154
East DorsetWest Moors and Holt6,363Christchurch3,31175735901530004,580
 Total70,332 35,23010,0594,02001,32600050,635

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

Old seat: Dorset North

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

Old seat: Dorset NorthTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
East DorsetAlderholt2,532Dorset Mid1,2803111890670001,847
East DorsetCrane2,619Dorset Mid1,4632541650290001,911
East DorsetHandley Vale2,273Dorset Mid1,2682241410250001,658
East DorsetSt Leonards1,239Christchurch68312483014000904
East DorsetStour2,011Dorset Mid1,0832151450240001,467
East DorsetVerwood East4,627Christchurch2,5194703340540003,377
East DorsetVerwood West5,322Christchurch2,6367004780690003,883
East DorsetWest Moors and Holt1,057Christchurch53613083023000772
North DorsetAbbey3,086Dorset Mid1,6173562020760002,251
North DorsetBlackmore2,857Dorset West1,4004012100730002,084
North DorsetBlandford Central3,301Dorset Mid1,14557958301010002,408
North DorsetBlandford Hilltop1,704Dorset Mid6993641370440001,244
North DorsetBlandford Langton St Leonards1,548Dorset Mid5362733000190001,128
North DorsetBlandford Old Town1,598Dorset Mid6082313010250001,165
North DorsetBulbarrow1,551Warminster and Shaftesbury7791961150410001,131
North DorsetGillingham Rural3,298Warminster and Shaftesbury1,5213874540430002,405
North DorsetGillingham Town4,948Warminster and Shaftesbury1,73494780401240003,609
North DorsetHill Forts5,294Warminster and Shaftesbury2,65368838201380003,861
North DorsetLower Tarrants2,607Dorset Mid1,3752941680650001,902
North DorsetLydden Vale1,525Dorset West789190960370001,112
North DorsetMotcombe and Bourton3,604Warminster and Shaftesbury1,8254582580880002,629
North DorsetRiversdale and Portman3,308Dorset Mid1,5515152520960002,414
North DorsetShaftesbury East2,733Warminster and Shaftesbury1,2025112430380001,994
North DorsetShaftesbury West3,120Warminster and Shaftesbury1,0954796090930002,276
North DorsetSturminster Newton3,411Warminster and Shaftesbury1,4624884520870002,489
North DorsetThe Beacon1,799Warminster and Shaftesbury9881761260220001,312
North DorsetThe Stours and Marnhull3,413Warminster and Shaftesbury1,7224312450920002,490
 Total76,385 36,16910,3927,55501,60700055,723

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

New seat: Christchurch

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

New seat: Christchurch
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
ChristchurchBurton and Winkton3,500Christchurch1,7105711960430002,520
ChristchurchGrange4,099Christchurch1,4671,09726001270002,951
ChristchurchHighcliffe2,907Christchurch1,5413791420310002,093
ChristchurchJumpers3,673Christchurch1,62164524601320002,644
ChristchurchMudeford and Friars Cliff4,195Christchurch2,2065532130480003,020
ChristchurchNorth Highcliffe and Walkford3,058Christchurch1,6104001550370002,202
ChristchurchPortfield3,765Christchurch1,5958282350520002,710
ChristchurchPurewell and Stanpit3,602Christchurch1,62161323101280002,593
ChristchurchSt Catherine's and Hurn3,126Christchurch1,6443961730380002,251
ChristchurchTown Centre3,536Christchurch1,65951624001310002,546
ChristchurchWest Highcliffe4,706Christchurch2,4426302580580003,388
East DorsetAmeysford2,444Christchurch1,2992901420290001,760
East DorsetFerndown Central7,077Christchurch3,7499053610800005,095
East DorsetHampreston and Longham2,914Christchurch1,6223041430290002,098
East DorsetParley4,534Christchurch2,40247724901370003,265
East DorsetSt Leonards5,770Christchurch3,2555782620590004,154
East DorsetSt Leonards1,239Dorset North68312483014000904
East DorsetVerwood East4,627Dorset North2,5194703340540003,377
East DorsetVerwood West5,322Dorset North2,6367004780690003,883
East DorsetWest Moors and Holt6,363Christchurch3,31175735901530004,580
East DorsetWest Moors and Holt1,057Dorset North53613083023000772
 Total81,514 41,12811,3634,84301,47200058,806

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