New Seat Details - Test Valley

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Test Valley 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	33,057	59.8%
LIB	14,359	26.0%
LAB	6,564	11.9%
Green	607	1.1%
UKIP	492	0.9%
OTH	156	0.3%
CON Majority	18,698	33.9%

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.

Test Valley: Map

List of old seats forming part of Test Valley

Old seat: Hampshire North West

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

Old seat: Hampshire North 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
Basingstoke and Deane	Baughurst and Tadley North	4,353	Hampshire North West	1,991	643	440	47	43	0	0	0	3,164
Basingstoke and Deane	Burghclere, Highclere and St Mary Bourne	4,556	Hampshire North West	2,549	538	237	37	40	0	0	0	3,401
Basingstoke and Deane	East Woodhay	2,221	Hampshire North West	1,251	290	76	41	20	0	0	0	1,678
Basingstoke and Deane	Kingsclere	3,860	Hampshire North West	1,976	610	230	36	38	0	0	0	2,890
Basingstoke and Deane	Oakley and North Waltham	5,388	Hampshire North West	2,617	757	281	103	99	0	0	0	3,857
Basingstoke and Deane	Overton, Laverstoke and Steventon	3,795	Hampshire North West	1,438	961	331	38	100	0	0	0	2,868
Basingstoke and Deane	Sherborne St John	147	Hampshire North West	83	17	7	1	2	0	0	0	110
Basingstoke and Deane	Tadley Central	2,067	Hampshire North West	926	334	262	25	24	0	0	0	1,571
Basingstoke and Deane	Tadley South	4,374	Hampshire North West	2,077	782	424	51	52	0	0	0	3,386
Basingstoke and Deane	Whitchurch	4,007	Hampshire North West	1,656	731	526	93	51	0	0	0	3,057
Test Valley	Alamein	6,818	Hampshire North West	2,571	1,782	579	157	191	0	0	0	5,280
Test Valley	Amport	1,820	Test Valley	883	274	70	51	19	0	0	0	1,297
Test Valley	Anna	3,740	Test Valley	2,156	467	192	73	38	0	0	0	2,926
Test Valley	Bourne Valley	1,641	Hampshire North West	895	208	93	28	14	0	0	0	1,238
Test Valley	Charlton	1,520	Hampshire North West	771	226	79	39	17	0	0	0	1,132
Test Valley	Harroway	5,740	Hampshire North West	2,898	1,082	310	146	180	0	0	0	4,616
Test Valley	Millway	5,512	Hampshire North West	2,700	959	378	132	162	0	0	0	4,331
Test Valley	Penton Bellinger	3,601	Test Valley	1,950	480	200	72	30	0	0	0	2,732
Test Valley	St Mary's	6,804	Hampshire North West	2,210	1,565	578	153	140	0	0	0	4,646
Test Valley	Winton	6,075	Hampshire North West	2,872	1,087	414	146	74	0	0	0	4,593
	Total	78,039		36,470	13,793	5,707	1,469	1,334	0	0	0	58,773

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

Old seat: Romsey and Southampton North

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

Old seat: Romsey and Southampton 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
Southampton	Bassett	8,890	Southampton Test	4,351	2,200	1,318	0	247	0	0	40	8,156
Southampton	Swaythling	7,385	Southampton Test	3,212	3,022	1,182	0	246	0	0	105	7,767
Test Valley	Abbey	3,786	Test Valley	1,469	408	667	0	73	0	0	13	2,630
Test Valley	Ampfield and Braishfield	1,803	Test Valley	883	141	208	0	13	0	0	7	1,252
Test Valley	Blackwater	4,103	New Forest East	2,062	306	434	0	66	0	0	5	2,873
Test Valley	Broughton and Stockbridge	3,582	Test Valley	1,865	278	396	0	24	0	0	28	2,591
Test Valley	Chilworth, Nursling and Rownhams	5,160	Test Valley	2,493	436	647	0	37	0	0	7	3,620
Test Valley	Cupernham	3,895	Test Valley	1,474	417	872	0	33	0	0	7	2,803
Test Valley	Dun Valley	1,733	New Forest East	895	140	270	0	12	0	0	4	1,321
Test Valley	Harewood	1,748	Test Valley	988	124	142	0	10	0	0	6	1,270
Test Valley	Kings Somborne and Michelmersh	2,106	Test Valley	1,046	160	259	0	13	0	0	3	1,481
Test Valley	North Baddesley	5,382	Test Valley	2,014	563	1,269	0	40	0	0	10	3,896
Test Valley	Over Wallop	1,369	Test Valley	948	125	139	0	8	0	0	2	1,222
Test Valley	Romsey Extra	3,395	Test Valley	1,174	279	416	0	52	0	0	19	1,940
Test Valley	Tadburn	3,989	Test Valley	1,446	435	1,034	0	38	0	0	7	2,960
Test Valley	Valley Park	5,575	Test Valley	2,345	580	1,410	0	42	0	0	8	4,385
	Total	63,901		28,665	9,614	10,663	0	954	0	0	271	50,167

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

Old seat: Winchester

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

Old seat: Winchester				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
Eastleigh	Chandler's Ford East	3,644	Test Valley	1,230	312	1,184	56	24	0	0	6	2,812
Eastleigh	Chandler's Ford West	4,581	Test Valley	1,583	281	1,570	61	29	0	0	5	3,529
Eastleigh	Hiltingbury East	4,021	Test Valley	1,814	211	895	51	21	0	0	6	2,998
Eastleigh	Hiltingbury West	4,105	Test Valley	1,927	218	991	46	25	0	0	14	3,221
Winchester	Colden Common and Twyford	4,252	Test Valley	1,762	268	1,123	51	24	0	0	5	3,233
Winchester	Compton and Otterbourne	3,251	Test Valley	1,607	107	675	31	14	0	0	3	2,437
Winchester	Itchen Valley	1,575	Winchester	818	45	234	5	7	0	0	5	1,114
Winchester	Kings Worthy	3,475	Winchester	1,196	213	1,081	41	20	0	0	14	2,565
Winchester	Littleton and Harestock	2,716	Winchester	1,198	124	735	15	15	0	0	2	2,089
Winchester	Olivers Battery and Badger Farm	3,044	Winchester	1,033	229	1,046	38	28	0	0	3	2,377
Winchester	Sparsholt	1,329	Winchester	768	37	311	6	10	0	0	6	1,138
Winchester	St Barnabas	4,618	Winchester	1,956	352	1,229	26	83	0	0	5	3,651
Winchester	St Bartholomew	4,557	Winchester	1,790	496	1,301	27	104	0	0	6	3,724
Winchester	St John and All Saints	3,935	Winchester	1,461	1,018	1,022	62	95	0	0	21	3,679
Winchester	St Luke	3,365	Winchester	1,333	739	1,506	25	83	0	0	22	3,708
Winchester	St Michael	4,433	Winchester	2,239	377	1,161	57	111	0	0	11	3,956
Winchester	St Paul	3,899	Winchester	1,711	463	1,530	53	110	0	0	5	3,872
Winchester	The Alresfords	4,869	Winchester	2,150	300	1,221	28	27	0	0	8	3,734
Winchester	Wonston and Micheldever	4,372	Winchester	2,155	219	917	16	16	0	0	3	3,326
	Total	70,041		29,731	6,009	19,732	695	846	0	0	150	57,163

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

New seat: Test Valley

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: Test Valley
Eastleigh	Chandler's Ford East	3,567	Winchester	1,230	312	1,184	56	24	0	0	6	2,812
Eastleigh	Chandler's Ford West	4,476	Winchester	1,583	281	1,570	61	29	0	0	5	3,529
Eastleigh	Hiltingbury East	3,801	Winchester	1,814	211	895	51	21	0	0	6	2,998
Eastleigh	Hiltingbury West	4,085	Winchester	1,927	218	991	46	25	0	0	14	3,221
Test Valley	Abbey	3,523	Romsey and Southampton North	1,469	408	667	0	73	0	0	13	2,630
Test Valley	Ampfield and Braishfield	1,678	Romsey and Southampton North	883	141	208	0	13	0	0	7	1,252
Test Valley	Amport	1,797	Hampshire North West	883	274	70	51	19	0	0	0	1,297
Test Valley	Anna	4,054	Hampshire North West	2,156	467	192	73	38	0	0	0	2,926
Test Valley	Broughton and Stockbridge	3,468	Romsey and Southampton North	1,865	278	396	0	24	0	0	28	2,591
Test Valley	Chilworth, Nursling and Rownhams	4,848	Romsey and Southampton North	2,493	436	647	0	37	0	0	7	3,620
Test Valley	Cupernham	3,754	Romsey and Southampton North	1,474	417	872	0	33	0	0	7	2,803
Test Valley	Harewood	1,701	Romsey and Southampton North	988	124	142	0	10	0	0	6	1,270
Test Valley	Kings Somborne and Michelmersh	1,984	Romsey and Southampton North	1,046	160	259	0	13	0	0	3	1,481
Test Valley	North Baddesley	5,217	Romsey and Southampton North	2,014	563	1,269	0	40	0	0	10	3,896
Test Valley	Over Wallop	1,635	Romsey and Southampton North	948	125	139	0	8	0	0	2	1,222
Test Valley	Penton Bellinger	3,785	Hampshire North West	1,950	480	200	72	30	0	0	0	2,732
Test Valley	Romsey Extra	2,598	Romsey and Southampton North	1,174	279	416	0	52	0	0	19	1,940
Test Valley	Tadburn	3,963	Romsey and Southampton North	1,446	435	1,034	0	38	0	0	7	2,960
Test Valley	Valley Park	5,875	Romsey and Southampton North	2,345	580	1,410	0	42	0	0	8	4,385
Winchester	Colden Common and Twyford	4,100	Winchester	1,762	268	1,123	51	24	0	0	5	3,233
Winchester	Compton and Otterbourne	3,091	Winchester	1,607	107	675	31	14	0	0	3	2,437
	Total	73,000		33,057	6,564	14,359	492	607	0	0	156	55,235

And these are the implied results for 2017 for the new seat of Test Valley. 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:	Caroline Nokes (CON)
County/Area:	Hampshire (South East)
Electorate:	73,000
Turnout:	75.7%

Test Valley: New Boundaries 2018 Calculation

Test Valley: Overview

Introduction