Devizes: New Boundaries 2018 Calculation

Devizes: Overview

 Projection: CON seat 

Implied MP at 2017: Claire Perry  (CON)
County/Area: Wiltshire (South West)
Electorate: 75,543
Turnout: 76.0%

 Implied 2017 VotesImplied 2017 Share
CON35,78662.3%
LAB12,18221.2%
LIB5,5479.7%
UKIP1,8603.2%
Green1,7363.0%
OTH2950.5%
CON Majority23,60441.1%

See overview of other seats in South West.

Devizes : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Devizes 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 Position7° Right1° Right
National Position6° Nat1° Nat1° Int
EU Leave %55%53%52%
British Identity25%27%29%
Good Health49%47%48%
UK Born98%92%88%
Good Education29%40%39%
Good Job41%50%51%
High SEC45%52%51%
Average Age49.550.548.5
ABC1 Class38%54%53%

Devizes ranks #265 for "Leave", #165 for "Right" and #227 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

Devizes: 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 Devizes 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 Devizes

The old seat(s) needed are:

Old seat: Devizes

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

Old seat: DevizesTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
WiltshireAldbourne and Ramsbury3,894Devizes1,848568153614000162,731
WiltshireBromham, Rowde and Potterne3,622Devizes1,473357148503550032,539
WiltshireBulford, Allington and Figheldean3,679Salisbury1,4427631314616500302,577
WiltshireBurbage and the Bedwyns3,606Devizes1,896484878500012,526
WiltshireDevizes and Roundway South3,236Devizes1,0337842345914300162,269
WiltshireDevizes East3,038Devizes971834155629600112,129
WiltshireDevizes North3,041Devizes9667851735813300162,131
WiltshireDurrington and Larkhill5,493Salisbury1,6274041,722592000193,851
WiltshireLudgershall and Perham Down4,370Devizes2,5022421461302900153,064
WiltshireMarlborough East3,013Devizes8907243391013300152,111
WiltshireMarlborough West3,229Devizes1,1786841781119200192,262
WiltshirePewsey3,455Devizes1,55963515110650012,421
WiltshirePewsey Vale3,328Devizes1,5793783138540012,333
WiltshireRoundway3,404Devizes1,4176871273411100102,386
WiltshireSummerham and Seend1,111Wiltshire West5231072510320000778
WiltshireThe Collingbournes and Netheravon3,094Devizes1,8492157411190012,169
WiltshireThe Lavingtons and Erlestoke4,354Devizes2,21358815847410043,051
WiltshireTidworth6,831Devizes3,8684212331864200384,788
WiltshireUrchfont and The Cannings3,184Devizes1,237474109350600022,232
WiltshireWest Selkley3,199Devizes1,674473504360042,241
 Total72,181 31,74510,6074,7061,7051,6040022250,589

The full details of these calculations are given on the Devizes 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
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
WiltshireBox and Colerne4,211Wiltshire North1,73154075259200483,168
WiltshireBrinkworth3,608Wiltshire North1,85440835831580052,714
WiltshireBy Brook3,642Wiltshire North1,919379347295400102,738
WiltshireCalne Central3,364Devizes1,239559582865100132,530
WiltshireCalne Chilvester and Abberd4,096Devizes1,773520586111810093,080
WiltshireCalne North3,862Devizes1,325752665796900142,904
WiltshireCalne Rural3,525Devizes1,660506319276400752,651
WiltshireCalne South and Cherhill3,800Devizes1,636512567607200112,858
WiltshireChippenham Cepen Park and Redlands64Wiltshire North271361100048
WiltshireChippenham Hardens and England21Wiltshire North6540000015
WiltshireCorsham Pickwick219Wiltshire West77512736000164
WiltshireCorsham Without and Box Hill1,828Wiltshire West85428018712350071,375
WiltshireCricklade and Latton4,020Wiltshire North1,69140484520560083,024
WiltshireKington3,975Wiltshire North2,03448437637550052,991
WiltshireLyneham4,412Wiltshire North2,3114053891166800293,318
WiltshireMalmesbury4,364Wiltshire North1,463762909261150093,284
WiltshireMinety3,827Wiltshire North1,916557291436000122,879
WiltshirePurton3,437Wiltshire North1,837372220294300852,586
WiltshireRoyal Wootton Bassett East3,562Wiltshire North1,9102404978170072,679
WiltshireRoyal Wootton Bassett North3,583Wiltshire North1,492538516944400112,695
WiltshireRoyal Wootton Bassett South4,152Wiltshire North1,601693695546700133,123
WiltshireSherston3,836Wiltshire North2,0454193821340052,886
 Total71,408 32,4019,3999,5208721,1420037653,710

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

New seat: Devizes

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

New seat: Devizes
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
WiltshireAldbourne and Ramsbury3,881Devizes1,848568153614000162,731
WiltshireBromham, Rowde and Potterne3,784Devizes1,473357148503550032,539
WiltshireBurbage and the Bedwyns3,719Devizes1,896484878500012,526
WiltshireCalne Central3,164Wiltshire North1,239559582865100132,530
WiltshireCalne Chilvester and Abberd3,770Wiltshire North1,773520586111810093,080
WiltshireCalne North3,095Wiltshire North1,325752665796900142,904
WiltshireCalne Rural3,398Wiltshire North1,660506319276400752,651
WiltshireCalne South and Cherhill3,689Wiltshire North1,636512567607200112,858
WiltshireDevizes and Roundway South3,392Devizes1,0337842345914300162,269
WiltshireDevizes East3,003Devizes971834155629600112,129
WiltshireDevizes North3,028Devizes9667851735813300162,131
WiltshireLudgershall and Perham Down3,350Devizes2,5022421461302900153,064
WiltshireMarlborough East3,170Devizes8907243391013300152,111
WiltshireMarlborough West2,848Devizes1,1786841781119200192,262
WiltshirePewsey3,743Devizes1,55963515110650012,421
WiltshirePewsey Vale3,451Devizes1,5793783138540012,333
WiltshireRoundway3,288Devizes1,4176871273411100102,386
WiltshireThe Collingbournes and Netheravon3,156Devizes1,8492157411190012,169
WiltshireThe Lavingtons and Erlestoke3,961Devizes2,21358815847410043,051
WiltshireTidworth3,759Devizes3,8684212331864200384,788
WiltshireUrchfont and The Cannings3,670Devizes1,237474109350600022,232
WiltshireWest Selkley3,224Devizes1,674473504360042,241
 Total75,543 35,78612,1825,5471,8601,7360029557,406

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


© 2017 Martin Baxter
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