New Seat Details - Aldridge, Brownhills and Bloxwich

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Aldridge, Brownhills and Bloxwich 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.

Party	Implied 2017 Votes	Implied 2017 Share
CON	31,834	63.1%
LAB	15,987	31.7%
LIB	1,446	2.9%
UKIP	646	1.3%
OTH	564	1.1%
CON Majority	15,847	31.4%

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.

Aldridge, Brownhills and Bloxwich: Map

List of old seats forming part of Aldridge, Brownhills and Bloxwich

Old seat: Aldridge-Brownhills

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

Old seat: Aldridge-Brownhills				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
Walsall	Aldridge Central and South	10,770	Aldridge, Brownhills and Bloxwich	5,070	1,742	351	0	0	0	0	97	7,260
Walsall	Aldridge North and Walsall Wood	9,918	Aldridge, Brownhills and Bloxwich	4,399	2,150	311	0	0	0	0	72	6,932
Walsall	Brownhills	9,218	Aldridge, Brownhills and Bloxwich	3,813	2,466	238	0	0	0	0	83	6,600
Walsall	Pelsall	8,758	Aldridge, Brownhills and Bloxwich	4,026	1,612	136	0	0	0	0	187	5,961
Walsall	Rushall-Shelfield	9,030	Aldridge, Brownhills and Bloxwich	3,608	2,465	155	0	0	0	0	61	6,289
Walsall	Streetly	10,665	Aldridge, Brownhills and Bloxwich	5,402	1,575	152	0	0	0	0	64	7,193
	Total	58,359		26,318	12,010	1,343	0	0	0	0	564	40,235

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

Old seat: Walsall North

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

Old seat: Walsall North				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
Walsall	Birchills Leamore	9,516	Walsall and Oscott	2,522	3,394	43	201	0	0	0	0	6,160
Walsall	Blakenall	8,023	Walsall and Oscott	2,357	2,791	30	334	0	0	0	0	5,512
Walsall	Bloxwich East	8,672	Aldridge, Brownhills and Bloxwich	2,481	2,084	46	310	0	0	0	0	4,921
Walsall	Bloxwich West	9,541	Aldridge, Brownhills and Bloxwich	3,035	1,893	57	336	0	0	0	0	5,321
Walsall	Short Heath	8,583	Wolverhampton East and Willenhall	2,602	1,516	139	356	0	0	0	0	4,613
Walsall	Willenhall North	9,275	Wolverhampton East and Willenhall	2,956	1,715	143	374	0	0	0	0	5,188
Walsall	Willenhall South	10,576	Wolverhampton East and Willenhall	2,967	2,925	129	384	0	0	0	0	6,405
	Total	64,186		18,920	16,318	587	2,295	0	0	0	0	38,120

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

New seat: Aldridge, Brownhills and Bloxwich

District	Ward	Electorate 2017	Old Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
New seat: Aldridge, Brownhills and Bloxwich
Walsall	Aldridge Central and South	10,891	Aldridge-Brownhills	5,070	1,742	351	0	0	0	0	97	7,260
Walsall	Aldridge North and Walsall Wood	10,401	Aldridge-Brownhills	4,399	2,150	311	0	0	0	0	72	6,932
Walsall	Bloxwich East	8,689	Walsall North	2,481	2,084	46	310	0	0	0	0	4,921
Walsall	Bloxwich West	9,394	Walsall North	3,035	1,893	57	336	0	0	0	0	5,321
Walsall	Brownhills	9,901	Aldridge-Brownhills	3,813	2,466	238	0	0	0	0	83	6,600
Walsall	Pelsall	8,943	Aldridge-Brownhills	4,026	1,612	136	0	0	0	0	187	5,961
Walsall	Rushall-Shelfield	9,435	Aldridge-Brownhills	3,608	2,465	155	0	0	0	0	61	6,289
Walsall	Streetly	10,792	Aldridge-Brownhills	5,402	1,575	152	0	0	0	0	64	7,193
	Total	78,446		31,834	15,987	1,446	646	0	0	0	564	50,477

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

Implied MP at 2017:	Wendy Morton (CON)
County/Area:	Black Country (West Midlands)
Electorate:	78,446
Turnout:	64.3%

Aldridge, Brownhills and Bloxwich: New Boundaries 2018 Calculation

Aldridge, Brownhills and Bloxwich: Overview

Introduction