Erewash: New Boundaries 2018 Calculation

Erewash: Overview

 Projection: CON seat 

Implied MP at 2017: Maggie Throup  (CON)
County/Area: Derbyshire (East Midlands)
Electorate: 75,973
Turnout: 71.3%

 Implied 2017 VotesImplied 2017 Share
CON28,55352.7%
LAB23,10242.6%
LIB1,2672.3%
Green7291.3%
OTH5201.0%
CON Majority5,45110.1%

See overview of other seats in East Midlands.

Erewash : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Erewash constituency, the 'East Midlands' 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.

IndicatorSeatEast MidlandsAll GB
Party WinnerCONCONCON
Economic Position3° Right3° Right
National Position11° Nat9° Nat1° Int
EU Leave %62%59%52%
British Identity27%27%29%
Good Health48%45%48%
UK Born96%91%88%
Good Education38%36%39%
Good Job50%48%51%
High SEC51%47%51%
Average Age49.649.148.5
ABC1 Class52%50%53%

Erewash ranks #106 for "Leave", #260 for "Right" and #99 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

Erewash: 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 Erewash 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 Erewash

The old seat(s) needed are:

Old seat: Derbyshire Mid

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

Old seat: Derbyshire MidTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
Amber ValleyBelper Central4,220Derbyshire Dales1,5341,3256902230003,151
Amber ValleyBelper East4,867Derbyshire Dales1,9541,4629901200003,635
Amber ValleyBelper North3,877Derbyshire Dales1,5761,0515202150002,894
Amber ValleyBelper South4,428Derbyshire Dales1,6661,3367502300003,307
Amber ValleyDuffield4,055Amber Valley2,01369021101150003,029
Amber ValleyKilburn, Denby and Holbrook72Amber Valley312020100054
DerbyAllestree10,933Amber Valley5,1182,3866170420008,163
DerbyOakwood10,651Derby East4,5572,9593620740007,952
DerbySpondon9,939Derby East4,3362,8721740380007,420
ErewashLittle Eaton and Stanley3,471Amber Valley1,684860260220002,592
ErewashOckbrook and Borrowash5,880Erewash2,6151,696230560004,390
ErewashWest Hallam and Dale Abbey5,073Amber Valley2,4301,241840320003,787
 Total67,466 29,51417,8981,79401,16800050,374

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

Old seat: Erewash

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

Old seat: ErewashTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
ErewashAwsworth Road3,657Erewash1,1141,3152301600262,494
ErewashBreaston3,459Erewash1,562740280700222,359
ErewashCotmanhay3,921Erewash1,1311,446506500282,675
ErewashDerby Road East4,080Erewash1,2471,4343904000232,783
ErewashDerby Road West5,681Erewash2,1151,49420202800363,875
ErewashDraycott and Risley3,274Erewash1,3657348602300252,233
ErewashHallam Fields3,753Erewash1,3361,1553201200252,560
ErewashKirk Hallam and Stanton-by-Dale5,212Erewash1,5931,914170600253,555
ErewashLarklands6,447Erewash1,9512,20369013400404,397
ErewashLittle Hallam3,521Erewash1,3289172807300552,401
ErewashLong Eaton Central5,567Erewash1,8651,60622103200733,797
ErewashNottingham Road3,512Erewash1,2441,0267702300242,394
ErewashSandiacre6,071Erewash2,3551,55150015000334,139
ErewashSawley5,145Erewash2,0031,35710202000273,509
ErewashShipley View3,867Erewash1,5001,039660800252,638
ErewashWilsthorpe5,823Erewash2,2291,47519903600333,972
 Total72,990 25,93821,4061,24406730052049,781

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

New seat: Erewash

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

New seat: Erewash
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
ErewashAwsworth Road3,431Erewash1,1141,3152301600262,494
ErewashBreaston3,706Erewash1,562740280700222,359
ErewashCotmanhay3,531Erewash1,1311,446506500282,675
ErewashDerby Road East3,587Erewash1,2471,4343904000232,783
ErewashDerby Road West5,583Erewash2,1151,49420202800363,875
ErewashDraycott and Risley3,232Erewash1,3657348602300252,233
ErewashHallam Fields3,502Erewash1,3361,1553201200252,560
ErewashKirk Hallam and Stanton-by-Dale4,975Erewash1,5931,914170600253,555
ErewashLarklands5,867Erewash1,9512,20369013400404,397
ErewashLittle Hallam3,437Erewash1,3289172807300552,401
ErewashLong Eaton Central5,180Erewash1,8651,60622103200733,797
ErewashNottingham Road3,658Erewash1,2441,0267702300242,394
ErewashOckbrook and Borrowash5,674Derbyshire Mid2,6151,696230560004,390
ErewashSandiacre5,922Erewash2,3551,55150015000334,139
ErewashSawley5,097Erewash2,0031,35710202000273,509
ErewashShipley View3,807Erewash1,5001,039660800252,638
ErewashWilsthorpe5,784Erewash2,2291,47519903600333,972
 Total75,973 28,55323,1021,26707290052054,171

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


© 2017 Martin Baxter
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