Yeovil and Somerset South: New Boundaries 2018 Calculation

Yeovil and Somerset South: Overview

 Projection: CON seat 

Implied MP at 2017: Marcus Fysh  (CON)
County/Area: Somerset (South West)
Electorate: 76,351
Turnout: 77.8%

 Implied 2017 VotesImplied 2017 Share
CON32,36754.5%
LIB17,64629.7%
LAB7,41712.5%
Green1,0521.8%
OTH9171.5%
CON Majority14,72124.8%

See overview of other seats in South West.

Yeovil and Somerset South : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Yeovil and Somerset South 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 Position4° Right1° Right
National Position3° Nat1° Nat1° Int
EU Leave %58%53%52%
British Identity24%27%29%
Good Health50%47%48%
UK Born95%92%88%
Good Education42%40%39%
Good Job46%50%51%
High SEC45%52%51%
Average Age49.350.548.5
ABC1 Class48%54%53%

Yeovil and Somerset South ranks #183 for "Leave", #249 for "Right" and #276 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

Yeovil and Somerset South: 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 Yeovil and Somerset South 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 Yeovil and Somerset South

The old seat(s) needed are:

Old seat: Yeovil

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

Old seat: YeovilTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
South SomersetBlackdown1,782Yeovil and Somerset South918692710800101,276
South SomersetBrympton5,629Yeovil and Somerset South2,1955431,23202900344,033
South SomersetChard Avishayes2,062Yeovil and Somerset South7202973970900541,477
South SomersetChard Combe1,645Yeovil and Somerset South6459735307300101,178
South SomersetChard Crimchard2,122Yeovil and Somerset South793137577050081,520
South SomersetChard Holyrood2,500Yeovil and Somerset South9771995930700161,792
South SomersetChard Jocelyn1,854Yeovil and Somerset South728154309019001191,329
South SomersetCoker4,126Yeovil and Somerset South1,82124685401900182,958
South SomersetCrewkerne6,075Yeovil and Somerset South2,2434471,328030800274,353
South SomersetEggwood1,878Yeovil and Somerset South805774420150061,345
South SomersetHamdon2,106Yeovil and Somerset South8487554802400131,508
South SomersetIlminster4,672Yeovil and Somerset South1,7783551,031015800253,347
South SomersetIvelchester3,351Yeovil and Somerset South1,556182383040002402,401
South SomersetNeroche1,874Yeovil and Somerset South97868281070061,340
South SomersetParrett1,799Yeovil and Somerset South795464180220081,289
South SomersetSouth Petherton3,781Yeovil and Somerset South1,4271601,06403800202,709
South SomersetSt Michael's1,793Yeovil and Somerset South7769139301300111,284
South SomersetTatworth and Forton2,067Yeovil and Somerset South880139335020001061,480
South SomersetWindwhistle1,792Yeovil and Somerset South881663070200091,283
South SomersetYeovil Central5,959Yeovil and Somerset South1,9398581,40403200364,269
South SomersetYeovil East5,919Yeovil and Somerset South1,8309961,34602900404,241
South SomersetYeovil South6,867Yeovil and Somerset South2,6688731,32901300364,919
South SomersetYeovil West5,949Yeovil and Somerset South2,1207871,29503000314,263
South SomersetYeovil Without5,310Yeovil and Somerset South2,0464551,156011400343,805
 Total82,912 32,3677,41717,64601,0520091759,399

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

New seat: Yeovil and Somerset South

The new seat of Yeovil and Somerset South is made up of the following wards, with the transfer-adjusted votes shown.

New seat: Yeovil and Somerset South
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
South SomersetBlackdown1,846Yeovil918692710800101,276
South SomersetBrympton4,822Yeovil2,1955431,23202900344,033
South SomersetChard Avishayes1,806Yeovil7202973970900541,477
South SomersetChard Combe1,590Yeovil6459735307300101,178
South SomersetChard Crimchard1,847Yeovil793137577050081,520
South SomersetChard Holyrood2,052Yeovil9771995930700161,792
South SomersetChard Jocelyn1,812Yeovil728154309019001191,329
South SomersetCoker4,098Yeovil1,82124685401900182,958
South SomersetCrewkerne6,092Yeovil2,2434471,328030800274,353
South SomersetEggwood1,911Yeovil805774420150061,345
South SomersetHamdon2,040Yeovil8487554802400131,508
South SomersetIlminster4,404Yeovil1,7783551,031015800253,347
South SomersetIvelchester2,275Yeovil1,556182383040002402,401
South SomersetNeroche1,975Yeovil97868281070061,340
South SomersetParrett1,855Yeovil795464180220081,289
South SomersetSouth Petherton3,898Yeovil1,4271601,06403800202,709
South SomersetSt Michael's1,754Yeovil7769139301300111,284
South SomersetTatworth and Forton2,083Yeovil880139335020001061,480
South SomersetWindwhistle1,830Yeovil881663070200091,283
South SomersetYeovil Central4,785Yeovil1,9398581,40403200364,269
South SomersetYeovil East4,656Yeovil1,8309961,34602900404,241
South SomersetYeovil South6,159Yeovil2,6688731,32901300364,919
South SomersetYeovil West4,910Yeovil2,1207871,29503000314,263
South SomersetYeovil Without5,851Yeovil2,0464551,156011400343,805
 Total76,351 32,3677,41717,64601,0520091759,399

And these are the implied results for 2017 for the new seat of Yeovil and Somerset South.


© 2017 Martin Baxter
Powered by TigerLib (11-Sep-2017 15:41)