Sefton Central: New Boundaries 2018 Calculation

Sefton Central: Overview

 Projection: LAB seat 

Implied MP at 2017: Bill Esterson  (LAB)
County/Area: Merseyside (North West)
Electorate: 76,378
Turnout: 77.1%

 Implied 2017 VotesImplied 2017 Share
LAB37,26963.3%
CON19,01632.3%
LIB1,7563.0%
Green7941.3%
OTH380.1%
LAB Majority18,25331.0%

See overview of other seats in North West.

Sefton Central : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Sefton Central constituency, the 'North 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.

IndicatorSeatNorth WestAll GB
Party WinnerLABLABCON
Economic Position14° Left6° Left
National Position8° Int2° Nat1° Int
EU Leave %42%54%52%
British Identity26%28%29%
Good Health49%46%48%
UK Born95%92%88%
Good Education42%37%39%
Good Job53%49%51%
High SEC57%48%51%
Average Age51.548.648.5
ABC1 Class57%50%53%

Sefton Central ranks #496 for "Leave", #536 for "Right" and #461 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

Sefton Central: 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 Sefton Central 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 Sefton Central

The old seat(s) needed are:

Old seat: Bootle

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

Old seat: BootleTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
SeftonChurch8,908Bootle9714,825151017300276,147
SeftonDerby9,143Bootle5845,6105004600206,310
SeftonFord9,511Bootle7005,7366303800266,563
SeftonLinacre9,115Bootle3485,71314013100856,291
SeftonLitherland8,441Bootle5415,04314806800255,825
SeftonNetherton and Orrell9,279Bootle6285,6141605100956,404
SeftonSt Oswald8,629Bootle4855,28018063001095,955
SeftonVictoria9,846Sefton Central1,8044,438377013900386,796
 Total72,872 6,06142,25983707090042550,291

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

Old seat: Sefton Central

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

Old seat: Sefton CentralTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
SeftonBlundellsands9,174Sefton Central2,4424,03631601280006,922
SeftonHarington9,762Sefton Central3,6343,51311901010007,367
SeftonManor10,096Sefton Central2,1075,2931370790007,616
SeftonMolyneux10,537Sefton Central1,8206,003330950007,951
SeftonPark9,706Sefton Central2,3204,6503010530007,324
SeftonRavenmeols9,625Sefton Central2,7724,19117701220007,262
SeftonSudell10,119Sefton Central2,1175,1452960770007,635
 Total69,019 17,21232,8311,379065500052,077

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

New seat: Sefton Central

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

New seat: Sefton Central
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
SeftonBlundellsands9,004Sefton Central2,4424,03631601280006,922
SeftonHarington9,560Sefton Central3,6343,51311901010007,367
SeftonManor9,574Sefton Central2,1075,2931370790007,616
SeftonMolyneux9,766Sefton Central1,8206,003330950007,951
SeftonPark9,456Sefton Central2,3204,6503010530007,324
SeftonRavenmeols9,162Sefton Central2,7724,19117701220007,262
SeftonSudell9,686Sefton Central2,1175,1452960770007,635
SeftonVictoria10,170Bootle1,8044,438377013900386,796
 Total76,378 19,01637,2691,7560794003858,873

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


© 2017 Martin Baxter
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