New Seat Details - Harrow South and Kenton

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Harrow South and Kenton 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	33,029	56.7%
CON	22,962	39.4%
LIB	1,300	2.2%
Green	696	1.2%
UKIP	220	0.4%
OTH	28	0.0%
LAB Majority	10,067	17.3%

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.

Harrow South and Kenton: Map

List of old seats forming part of Harrow South and Kenton

Old seat: Brent North

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

Old seat: Brent 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
Brent	Alperton	8,991	Wembley	1,345	4,535	200	0	63	0	0	13	6,156
Brent	Barnhill	9,956	Wembley	2,192	4,430	186	0	96	0	0	48	6,952
Brent	Fryent	8,035	Wembley	1,819	3,821	147	0	78	0	0	28	5,893
Brent	Kenton	8,568	Harrow South and Kenton	2,635	2,503	123	0	57	0	0	16	5,334
Brent	Northwick Park	8,919	Ealing North and Sudbury	2,404	3,014	130	0	62	0	0	20	5,630
Brent	Preston	9,237	Wembley	2,543	3,903	192	0	83	0	0	41	6,762
Brent	Queensbury	9,697	Harrow South and Kenton	2,553	3,892	136	0	64	0	0	12	6,657
Brent	Sudbury	8,874	Ealing North and Sudbury	1,577	4,601	262	0	88	0	0	49	6,577
Brent	Wembley Central	9,087	Wembley	1,367	4,796	238	0	71	0	0	13	6,485
	Total	81,364		18,435	35,495	1,614	0	662	0	0	240	56,446

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

Old seat: Harrow East

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

Old seat: Harrow East				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
Harrow	Belmont	7,695	Harrow North	3,074	2,238	205	0	59	0	0	0	5,576
Harrow	Canons	9,272	Harrow North	3,533	2,197	311	0	75	0	0	0	6,116
Harrow	Edgware	7,014	Harrow South and Kenton	2,415	3,119	116	0	59	0	0	0	5,709
Harrow	Harrow Weald	7,968	Harrow North	2,887	2,244	344	0	79	0	0	0	5,554
Harrow	Kenton East	7,329	Harrow South and Kenton	2,314	3,004	97	0	50	0	0	0	5,465
Harrow	Kenton West	8,036	Harrow South and Kenton	2,702	2,588	139	0	50	0	0	0	5,479
Harrow	Queensbury	7,392	Harrow South and Kenton	2,491	3,100	142	0	135	0	0	0	5,868
Harrow	Stanmore Park	8,349	Harrow North	3,657	1,668	86	0	60	0	0	0	5,471
Harrow	Wealdstone	6,809	Harrow North	2,057	3,214	134	0	205	0	0	0	5,610
	Total	69,864		25,130	23,372	1,574	0	772	0	0	0	50,848

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

Old seat: Harrow West

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

Old seat: Harrow West				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
Harrow	Greenhill	7,343	Harrow South and Kenton	1,875	3,695	219	68	142	0	0	0	5,999
Harrow	Harrow on the Hill	7,357	Harrow South and Kenton	2,521	3,142	132	75	57	0	0	0	5,927
Harrow	Headstone North	7,593	Harrow North	2,149	2,527	96	71	38	0	0	0	4,881
Harrow	Headstone South	7,445	Harrow North	1,773	3,341	192	32	53	0	0	0	5,391
Harrow	Marlborough	7,523	Harrow North	1,736	3,914	94	40	141	0	0	0	5,925
Harrow	Rayners Lane	7,539	Harrow North	1,964	3,124	167	76	91	0	0	0	5,422
Harrow	Roxbourne	8,078	Harrow South and Kenton	1,676	4,294	148	34	44	0	0	0	6,196
Harrow	Roxeth	7,432	Harrow South and Kenton	1,780	3,692	48	43	38	0	0	0	5,601
Harrow	West Harrow	7,115	Harrow North	1,853	2,910	170	31	47	0	0	0	5,011
	Total	67,425		17,327	30,639	1,266	470	651	0	0	0	50,353

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

New seat: Harrow South and Kenton

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: Harrow South and Kenton
Brent	Kenton	7,800	Brent North	2,635	2,503	123	0	57	0	0	16	5,334
Brent	Queensbury	9,734	Brent North	2,553	3,892	136	0	64	0	0	12	6,657
Harrow	Edgware	8,057	Harrow East	2,415	3,119	116	0	59	0	0	0	5,709
Harrow	Greenhill	8,316	Harrow West	1,875	3,695	219	68	142	0	0	0	5,999
Harrow	Harrow on the Hill	8,217	Harrow West	2,521	3,142	132	75	57	0	0	0	5,927
Harrow	Kenton East	7,713	Harrow East	2,314	3,004	97	0	50	0	0	0	5,465
Harrow	Kenton West	7,733	Harrow East	2,702	2,588	139	0	50	0	0	0	5,479
Harrow	Queensbury	8,281	Harrow East	2,491	3,100	142	0	135	0	0	0	5,868
Harrow	Roxbourne	8,587	Harrow West	1,676	4,294	148	34	44	0	0	0	6,196
Harrow	Roxeth	7,765	Harrow West	1,780	3,692	48	43	38	0	0	0	5,601
	Total	82,203		22,962	33,029	1,300	220	696	0	0	28	58,235

And these are the implied results for 2017 for the new seat of Harrow South and Kenton. 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:	Gareth Thomas (LAB)
County/Area:	Harrow (London)
Electorate:	82,203
Turnout:	70.8%

Harrow South and Kenton: New Boundaries 2018 Calculation

Harrow South and Kenton: Overview

Introduction