Ipswich: New Boundaries 2018 Calculation

Ipswich: Overview

Projection: LAB seat

Implied MP at 2017:Sandy Martin  (LAB)
County/Area:Suffolk (Anglia)
Electorate:80,644
Turnout:68.7%

PartyImplied 2017 VotesImplied 2017 Share
LAB25,65946.3%
CON25,64046.3%
UKIP1,5632.8%
LIB1,4102.5%
Green9761.8%
OTH1200.2%
LAB Majority190.0%

See overview of other seats in Anglia.



Introduction

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

Ipswich: Map

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

List of old seats forming part of Ipswich

The old seat(s) needed are:

Old seat: Ipswich

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

Old seat: IpswichTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
IpswichAlexandra5,618Ipswich1,8702,344149669000214,540
IpswichBixley5,434Ipswich2,0041,07079100490043,306
IpswichBridge5,223Ipswich1,7042,05787129660094,052
IpswichGainsborough5,747Ipswich1,6692,19945125620064,106
IpswichGipping5,191Ipswich1,6212,23873127670074,133
IpswichHolywells5,040Ipswich1,9011,50892105600063,672
IpswichPriory Heath5,796Ipswich1,8192,14569122600054,220
IpswichRushmere5,862Ipswich1,8611,731125112670053,901
IpswichSprites5,003Ipswich1,4281,5175096400043,135
IpswichSt John's6,054Ipswich2,0101,966116126720064,296
IpswichSt Margaret's5,912Ipswich2,1051,32413950740053,697
IpswichStoke Park4,910Ipswich1,6401,6046558490073,423
IpswichWestgate4,912Ipswich1,7632,520991568400354,657
 Total70,702 23,39524,2231,1881,3728400012051,138

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

Old seat: Suffolk Central and Ipswich North

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

Old seat: Suffolk Central and Ipswich NorthTransfer-adjusted Results
DistrictWardElectorate
2017
New SeatCON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
IpswichCastle Hill5,582Ipswich2,2451,4362221911360004,230
IpswichWhitehouse5,655Central Suffolk2,0752,3722202401640005,071
IpswichWhitton5,588Central Suffolk2,1202,09923388850004,625
Mid SuffolkBarking and Somersham1,785Central Suffolk7553177961210001,233
Mid SuffolkBramford and Blakenham3,406Central Suffolk1,330608163115430002,259
Mid SuffolkClaydon and Barham3,604Central Suffolk1,731624167471090002,678
Mid SuffolkDebenham1,866Central Suffolk7814045557560001,353
Mid SuffolkEye1,701Central Suffolk7333623726730001,231
Mid SuffolkFressingfield1,931Central Suffolk8613356722220001,307
Mid SuffolkHelmingham and Coddenham1,799Central Suffolk9512666619220001,324
Mid SuffolkHoxne1,670Central Suffolk7803221918340001,173
Mid SuffolkMendlesham1,802Central Suffolk8023623025710001,290
Mid SuffolkPalgrave1,806Central Suffolk9063162523510001,321
Mid SuffolkStradbroke and Laxfield2,125Central Suffolk1,0203223226610001,461
Mid SuffolkThe Stonhams1,801Central Suffolk9032857221530001,334
Mid SuffolkWetheringsett1,993Central Suffolk1,0063232523640001,441
Mid SuffolkWorlingworth1,923Central Suffolk1,0652581822220001,385
Suffolk CoastalFramlingham4,236Central Suffolk2,138736691431430003,229
Suffolk CoastalFynn Valley2,470Central Suffolk1,2553613829700001,753
Suffolk CoastalGrundisburgh2,540Central Suffolk1,25846210230330001,885
Suffolk CoastalHacheston2,221Central Suffolk1,0913757125700001,632
Suffolk CoastalKesgrave East4,841Central Suffolk2,5601,19125369730004,146
Suffolk CoastalKesgrave West5,333Central Suffolk2,4561,198140171750004,040
Suffolk CoastalTower4,059Central Suffolk1,9308249452510002,951
Suffolk CoastalWickham Market2,083Central Suffolk8774639571290001,535
Suffolk CoastalWoodbridge878Suffolk Coastal364182392129000635
 Total74,698 33,99316,8032,4311,6351,66000056,522

The full details of these calculations are given on the Suffolk Central and Ipswich North seat details page. Click on "Show workings".

New seat: Ipswich

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

New seat: Ipswich
DistrictWardElectorate
2017
Old Seat CON
Votes
LAB
Votes
LIB
Votes
UKIP
Votes
Green
Votes
NAT
Votes
MIN
Votes
OTH
Votes
Total
Votes
IpswichAlexandra6,640Ipswich1,8702,344149669000214,540
IpswichBixley4,835Ipswich2,0041,07079100490043,306
IpswichBridge5,927Ipswich1,7042,05787129660094,052
IpswichCastle Hill5,846Suffolk Central and Ipswich North2,2451,4362221911360004,230
IpswichGainsborough6,007Ipswich1,6692,19945125620064,106
IpswichGipping6,046Ipswich1,6212,23873127670074,133
IpswichHolywells5,372Ipswich1,9011,50892105600063,672
IpswichPriory Heath6,172Ipswich1,8192,14569122600054,220
IpswichRushmere5,706Ipswich1,8611,731125112670053,901
IpswichSprites4,586Ipswich1,4281,5175096400043,135
IpswichSt John's6,282Ipswich2,0101,966116126720064,296
IpswichSt Margaret's5,407Ipswich2,1051,32413950740053,697
IpswichStoke Park5,006Ipswich1,6401,6046558490073,423
IpswichWestgate6,812Ipswich1,7632,520991568400354,657
 Total80,644 25,64025,6591,4101,5639760012055,368

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


© 2024 Electoral Calculus Ltd
Powered by TigerLib (14-Mar-2024 12:19, Py3L, sc675)