Oldham: New Boundaries 2018 Calculation

Oldham: Overview

 Projection: LAB seat 

Implied MP at 2017: Jim McMahon  (LAB)
County/Area: Eastern Manchester (North West)
Electorate: 73,825
Turnout: 62.5%

 Implied 2017 VotesImplied 2017 Share
LAB28,23561.2%
CON13,71429.7%
UKIP2,8516.2%
LIB1,0532.3%
Green2560.6%
OTH90.0%
LAB Majority14,52131.5%

See overview of other seats in North West.

Oldham : Political and Demographic indicators

The table below shows some political and demographic numerical indicators for the new Oldham 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 Position6° Left6° Left
National Position10° Nat2° Nat1° Int
EU Leave %64%54%52%
British Identity28%28%29%
Good Health46%46%48%
UK Born82%92%88%
Good Education40%37%39%
Good Job46%49%51%
High SEC40%48%51%
Average Age43.348.648.5
ABC1 Class49%50%53%

Oldham ranks #83 for "Leave", #445 for "Right" and #112 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

Oldham: 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 Oldham 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 Oldham

The old seat(s) needed are:

Old seat: Manchester Central

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

Old seat: Manchester CentralTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
ManchesterAncoats and Clayton11,115Manchester Central8114,7391832419000586,122
ManchesterArdwick12,131Manchester Central5125,787266137600296,683
ManchesterBradford10,661Manchester Central7994,7541181174700375,872
ManchesterCity Centre11,899Manchester Central1,9793,774547701840016,555
ManchesterHulme11,465Manchester Central9204,9171377525100156,315
ManchesterMiles Platting and Newton Heath9,988Manchester Central5714,5221572042800195,501
ManchesterMoss Side13,196Manchester Central5066,418158415900257,270
ManchesterMoston9,805Oldham9463,578113744120095,402
 Total90,260 7,04438,4891,6791,4688470019349,720

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

Old seat: Oldham East and Saddleworth

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

Old seat: Oldham East and SaddleworthTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
OldhamAlexandra8,597Failsworth and Droylsden1,5753,6637428600005,598
OldhamCrompton7,614Littleborough and Saddleworth2,1942,24820930800004,959
OldhamSaddleworth North6,868Littleborough and Saddleworth2,2521,84325912000004,474
OldhamSaddleworth South7,142Littleborough and Saddleworth2,6601,65423210500004,651
OldhamSaddleworth West and Lees7,855Littleborough and Saddleworth2,1712,47917229300005,115
OldhamShaw7,483Littleborough and Saddleworth1,8802,42027030300004,873
OldhamSt James'8,182Oldham1,7423,07211739700005,328
OldhamSt Mary's9,949Failsworth and Droylsden1,3214,82222710800006,478
OldhamWaterhead8,535Oldham1,6523,42712235800005,559
 Total72,225 17,44725,6281,6822,278000047,035

The full details of these calculations are given on the Oldham East and Saddleworth seat details page. Click on "Show workings".

Old seat: Oldham West and Royton

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

Old seat: Oldham West and RoytonTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
OldhamChadderton Central7,335Oldham1,7022,61844218560004,638
OldhamChadderton North7,847Oldham1,7882,88770176410004,962
OldhamChadderton South7,782Oldham1,4363,02942361510004,919
OldhamColdhurst9,269Oldham8934,5163836630005,861
OldhamHollinwood7,815Failsworth and Droylsden1,2333,27856311630004,941
OldhamMedlock Vale8,787Failsworth and Droylsden1,2713,94174198720005,556
OldhamRoyton North7,264Oldham1,7792,43678251480004,592
OldhamRoyton South7,683Oldham1,7762,67284280450004,857
OldhamWerneth8,635Failsworth and Droylsden7714,46812537590005,460
 Total72,417 12,64929,8459561,89843800045,786

The full details of these calculations are given on the Oldham West and Royton seat details page. Click on "Show workings".

New seat: Oldham

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

New seat: Oldham
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
ManchesterMoston11,166Manchester Central9463,578113744120095,402
OldhamChadderton Central7,782Oldham West and Royton1,7022,61844218560004,638
OldhamChadderton North8,114Oldham West and Royton1,7882,88770176410004,962
OldhamChadderton South7,509Oldham West and Royton1,4363,02942361510004,919
OldhamColdhurst7,933Oldham West and Royton8934,5163836630005,861
OldhamRoyton North7,736Oldham West and Royton1,7792,43678251480004,592
OldhamRoyton South8,105Oldham West and Royton1,7762,67284280450004,857
OldhamSt James'7,556Oldham East and Saddleworth1,7423,07211739700005,328
OldhamWaterhead7,924Oldham East and Saddleworth1,6523,42712235800005,559
 Total73,825 13,71428,2351,0532,85125600946,118

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


© 2017 Martin Baxter
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