Sheffield South East: New Boundaries 2018 Calculation

Sheffield South East: Overview

Projection: LAB seat

Implied MP at 2017:Clive Betts  (LAB)
County/Area:South Yorkshire (Yorks/Humber)
Electorate:76,126
Turnout:62.9%

PartyImplied 2017 VotesImplied 2017 Share
LAB28,70660.0%
CON14,43430.2%
UKIP3,0346.3%
LIB1,4953.1%
OTH1280.3%
Green720.2%
LAB Majority14,27229.8%

See overview of other seats in Yorks/Humber.



Introduction

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

Sheffield South East: Map

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

List of old seats forming part of Sheffield South East

The old seat(s) needed are:

Old seat: Sheffield Brightside and Hillsborough

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

Old seat: Sheffield Brightside and HillsboroughTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
SheffieldBurngreave13,617Sheffield North and Ecclesfield;
Sheffield South East
1,7908,017155542182006710,753
SheffieldFirth Park13,772Sheffield North and Ecclesfield1,6835,76615754413300318,314
SheffieldHillsborough13,707Sheffield Central2,0334,11638048415700327,202
SheffieldShiregreen and Brightside13,576Sheffield North and Ecclesfield1,8565,41217755914300158,162
SheffieldSouthey13,045Sheffield North and Ecclesfield1,6894,88319251612100407,441
 Total67,717 9,05128,1941,0612,6457360018541,872

The full details of these calculations are given on the Sheffield Brightside and Hillsborough seat details page. Click on "Show workings".

Old seat: Sheffield South East

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

Old seat: Sheffield South EastTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
SheffieldBeighton13,027Sheffield South East3,0334,204282536000138,068
SheffieldBirley12,591Sheffield South East2,3994,576300542000157,832
SheffieldDarnall14,743Sheffield South East2,6447,4592336230003810,997
SheffieldMosborough13,490Sheffield South East3,0964,366360558000148,394
SheffieldWoodhouse13,136Sheffield South East2,5514,915258560000218,305
 Total66,987 13,72325,5201,4332,81900010143,596

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

New seat: Sheffield South East

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

New seat: Sheffield South East
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
SheffieldBeighton12,760Sheffield South East3,0334,204282536000138,068
SheffieldBirley12,385Sheffield South East2,3994,576300542000157,832
SheffieldBurngreave7,180Sheffield Brightside and Hillsborough7113,186622157200274,273
SheffieldDarnall17,391Sheffield South East2,6447,4592336230003810,997
SheffieldMosborough13,277Sheffield South East3,0964,366360558000148,394
SheffieldWoodhouse13,133Sheffield South East2,5514,915258560000218,305
 Total76,126 14,43428,7061,4953,034720012847,869

And these are the implied results for 2017 for the new seat of Sheffield South East. 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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