New Seat Details - Uxbridge and Northolt

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Uxbridge and Northolt 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
LAB	24,962	46.4%
CON	24,395	45.3%
LIB	1,859	3.5%
UKIP	1,748	3.2%
Green	874	1.6%
LAB Majority	567	1.1%

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.

Uxbridge and Northolt: Map

List of old seats forming part of Uxbridge and Northolt

Old seat: Ealing North

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

Old seat: Ealing 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
Ealing	Cleveland	9,209	Ealing North and Sudbury	2,304	3,537	234	57	159	0	0	0	6,291
Ealing	Greenford Broadway	10,465	Ealing North and Sudbury	1,827	5,443	165	80	57	0	0	0	7,572
Ealing	Greenford Green	8,405	Ealing North and Sudbury	2,134	3,818	152	76	109	0	0	0	6,289
Ealing	Hobbayne	8,858	Ealing North and Sudbury	1,748	4,027	188	70	143	0	0	0	6,176
Ealing	North Greenford	8,849	Ealing North and Sudbury	1,721	4,299	140	184	42	0	0	0	6,386
Ealing	Northolt Mandeville	9,381	Uxbridge and Northolt	1,839	4,357	132	191	51	0	0	0	6,570
Ealing	Northolt West End	9,598	Uxbridge and Northolt	1,434	4,800	104	190	47	0	0	0	6,575
Ealing	Perivale	8,938	Ealing North and Sudbury	1,934	4,355	159	73	134	0	0	0	6,655
	Total	73,703		14,941	34,636	1,274	921	742	0	0	0	52,514

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

Old seat: Uxbridge and South Ruislip

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

Old seat: Uxbridge and South Ruislip				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
Hillingdon	Brunel	7,831	Uxbridge and Northolt	3,003	2,778	206	222	143	0	0	0	6,352
Hillingdon	Cavendish	8,433	Uxbridge and Northolt	3,192	1,709	193	176	109	0	0	0	5,379
Hillingdon	Hillingdon East	8,481	Uxbridge and Northolt	2,998	2,407	303	202	55	0	0	0	5,965
Hillingdon	Manor	8,236	Uxbridge and Northolt	3,066	1,668	228	172	109	0	0	0	5,243
Hillingdon	South Ruislip	8,305	Uxbridge and Northolt	2,927	2,272	215	215	93	0	0	0	5,722
Hillingdon	Uxbridge North	9,225	Uxbridge and Northolt	3,227	1,921	197	169	103	0	0	0	5,617
Hillingdon	Uxbridge South	7,698	Uxbridge and Northolt	2,709	3,050	281	211	164	0	0	0	6,415
Hillingdon	Yiewsley	8,397	Hayes and Harlington	2,594	2,877	211	210	108	0	0	0	6,000
	Total	66,606		23,716	18,682	1,834	1,577	884	0	0	0	46,693

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

New seat: Uxbridge and Northolt

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: Uxbridge and Northolt
Ealing	Northolt Mandeville	9,354	Ealing North	1,839	4,357	132	191	51	0	0	0	6,570
Ealing	Northolt West End	9,361	Ealing North	1,434	4,800	104	190	47	0	0	0	6,575
Hillingdon	Brunel	9,515	Uxbridge and South Ruislip	3,003	2,778	206	222	143	0	0	0	6,352
Hillingdon	Cavendish	8,057	Uxbridge and South Ruislip	3,192	1,709	193	176	109	0	0	0	5,379
Hillingdon	Hillingdon East	8,933	Uxbridge and South Ruislip	2,998	2,407	303	202	55	0	0	0	5,965
Hillingdon	Manor	7,854	Uxbridge and South Ruislip	3,066	1,668	228	172	109	0	0	0	5,243
Hillingdon	South Ruislip	8,569	Uxbridge and South Ruislip	2,927	2,272	215	215	93	0	0	0	5,722
Hillingdon	Uxbridge North	8,413	Uxbridge and South Ruislip	3,227	1,921	197	169	103	0	0	0	5,617
Hillingdon	Uxbridge South	9,610	Uxbridge and South Ruislip	2,709	3,050	281	211	164	0	0	0	6,415
	Total	79,666		24,395	24,962	1,859	1,748	874	0	0	0	53,838

And these are the implied results for 2017 for the new seat of Uxbridge and Northolt. 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:	Unknown (changed seat) (LAB)
County/Area:	Hillingdon (London)
Electorate:	79,666
Turnout:	67.6%

Uxbridge and Northolt: New Boundaries 2018 Calculation

Uxbridge and Northolt: Overview

Introduction