Staffordshire South: New Boundaries 2018 Calculation

Staffordshire South: Overview

Projection: CON seat

Implied MP at 2017:Gavin Williamson  (CON)
County/Area:Staffordshire (West Midlands)
Electorate:73,454
Turnout:69.6%

PartyImplied 2017 VotesImplied 2017 Share
CON35,65769.8%
LAB12,92125.3%
LIB1,3472.6%
Green1,1852.3%
CON Majority22,73644.5%

See overview of other seats in West Midlands.



Introduction

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Staffordshire 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.

Staffordshire South: Map

Boundary Lines courtesy of Ordnance Survey OpenData © Crown copyright 2015, Map © OpenStreetMap contributors

List of old seats forming part of Staffordshire South

The old seat(s) needed are:

Old seat: Staffordshire South

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

Old seat: Staffordshire SouthTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
South StaffordshireBilbrook3,160Staffordshire South1,5436297301130002,358
South StaffordshireBrewood and Coven5,374Staffordshire South2,4171,037900600003,604
South StaffordshireCheslyn Hay North and Saredon3,327Staffordshire South1,4247366101120002,333
South StaffordshireCheslyn Hay South2,908Staffordshire South1,340655680370002,100
South StaffordshireCodsall North3,265Staffordshire South1,688426620370002,213
South StaffordshireCodsall South3,135Staffordshire South1,812355520370002,256
South StaffordshireEssington4,020Staffordshire South1,899665620460002,672
South StaffordshireFeatherstone and Shareshill3,663Staffordshire South1,8949569201860003,128
South StaffordshireGreat Wyrley Landywood3,639Staffordshire South1,685906710440002,706
South StaffordshireGreat Wyrley Town4,936Staffordshire South2,0871,119850540003,345
South StaffordshireHimley and Swindon1,788Staffordshire South810210220600001,102
South StaffordshireHuntington and Hatherton3,835Staffordshire South1,4241,261680450002,798
South StaffordshireKinver5,912Staffordshire South3,160636840660003,946
South StaffordshirePattingham and Patshull1,805Staffordshire South986193270200001,226
South StaffordshirePerton Dippons1,530Staffordshire South845214300200001,109
South StaffordshirePerton East1,689Staffordshire South903279460270001,255
South StaffordshirePerton Lakeside4,657Staffordshire South2,4318671220700003,490
South StaffordshireTrysull and Seisdon1,759Staffordshire South997182180160001,213
South StaffordshireWombourne North and Lower Penn5,203Staffordshire South2,800622900560003,568
South StaffordshireWombourne South East3,119Staffordshire South1,625386560360002,103
South StaffordshireWombourne South West3,408Staffordshire South1,887587680430002,585
 Total72,132 35,65712,9211,34701,18500051,110

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

New seat: Staffordshire South

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

New seat: Staffordshire South
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
South StaffordshireBilbrook3,391Staffordshire South1,5436297301130002,358
South StaffordshireBrewood and Coven5,179Staffordshire South2,4171,037900600003,604
South StaffordshireCheslyn Hay North and Saredon3,353Staffordshire South1,4247366101120002,333
South StaffordshireCheslyn Hay South3,018Staffordshire South1,340655680370002,100
South StaffordshireCodsall North3,180Staffordshire South1,688426620370002,213
South StaffordshireCodsall South3,244Staffordshire South1,812355520370002,256
South StaffordshireEssington3,840Staffordshire South1,899665620460002,672
South StaffordshireFeatherstone and Shareshill4,495Staffordshire South1,8949569201860003,128
South StaffordshireGreat Wyrley Landywood3,889Staffordshire South1,685906710440002,706
South StaffordshireGreat Wyrley Town4,808Staffordshire South2,0871,119850540003,345
South StaffordshireHimley and Swindon1,583Staffordshire South810210220600001,102
South StaffordshireHuntington and Hatherton4,021Staffordshire South1,4241,261680450002,798
South StaffordshireKinver5,671Staffordshire South3,160636840660003,946
South StaffordshirePattingham and Patshull1,762Staffordshire South986193270200001,226
South StaffordshirePerton Dippons1,594Staffordshire South845214300200001,109
South StaffordshirePerton East1,803Staffordshire South903279460270001,255
South StaffordshirePerton Lakeside5,014Staffordshire South2,4318671220700003,490
South StaffordshireTrysull and Seisdon1,743Staffordshire South997182180160001,213
South StaffordshireWombourne North and Lower Penn5,127Staffordshire South2,800622900560003,568
South StaffordshireWombourne South East3,023Staffordshire South1,625386560360002,103
South StaffordshireWombourne South West3,716Staffordshire South1,887587680430002,585
 Total73,454 35,65712,9211,34701,18500051,110

And these are the implied results for 2017 for the new seat of Staffordshire South. Please note that the wards used are those of 2015 in order to be consistent with those used by the Boundary Commissions.


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