New Seat Details - Chesham and Amersham

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Chesham and Amersham 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	37,878	61.7%
LAB	12,523	20.4%
LIB	7,534	12.3%
Green	1,769	2.9%
UKIP	1,581	2.6%
OTH	57	0.1%
CON Majority	25,355	41.3%

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.

Chesham and Amersham: Map

List of old seats forming part of Chesham and Amersham

Old seat: Aylesbury

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

Old seat: Aylesbury				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
Aylesbury Vale	Aston Clinton and Stoke Mandeville	7,422	Aylesbury	3,485	1,228	269	119	114	0	0	42	5,257
Aylesbury Vale	Bedgrove	4,886	Aylesbury	2,057	864	241	85	80	0	0	92	3,419
Aylesbury Vale	Central and Walton	4,233	Aylesbury	1,632	1,203	416	82	89	0	0	33	3,455
Aylesbury Vale	Coldharbour	6,070	Aylesbury	2,409	1,672	707	127	119	0	0	49	5,083
Aylesbury Vale	Elmhurst	4,285	Aylesbury	1,501	1,566	439	79	86	0	0	41	3,712
Aylesbury Vale	Gatehouse	4,798	Aylesbury	1,625	1,415	532	100	91	0	0	38	3,801
Aylesbury Vale	Mandeville and Elm Farm	6,329	Aylesbury	2,608	1,479	381	121	115	0	0	44	4,748
Aylesbury Vale	Oakfield and Bierton	3,905	Aylesbury	1,590	976	460	84	67	0	0	31	3,208
Aylesbury Vale	Riverside	4,966	Aylesbury	1,226	927	281	68	28	0	0	23	2,553
Aylesbury Vale	Southcourt	4,070	Aylesbury	1,391	1,521	431	74	76	0	0	36	3,529
Aylesbury Vale	Walton Court and Hawkslade	4,179	Aylesbury	1,538	1,244	521	92	44	0	0	32	3,471
Aylesbury Vale	Watermead	1,656	Aylesbury	748	332	141	28	15	0	0	12	1,276
Aylesbury Vale	Wendover and Halton	6,288	Aylesbury	2,855	1,115	286	102	109	0	0	38	4,505
Wycombe	Bledlow and Bradenham	2,149	Wycombe	1,237	266	59	14	29	0	0	27	1,632
Wycombe	Greater Hughenden	6,486	Chesham and Amersham	3,192	894	291	46	83	0	0	48	4,554
Wycombe	Lacey Green, Speen and the Hampdens	2,043	Chesham and Amersham	1,172	256	62	11	27	0	0	9	1,537
Wycombe	Stokenchurch and Radnage	4,137	Wycombe	2,048	659	143	64	63	0	0	27	3,004
	Total	77,902		32,314	17,617	5,660	1,296	1,235	0	0	622	58,744

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

Old seat: Chesham and Amersham

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

Old seat: Chesham and Amersham				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
Chiltern	Amersham Common	1,865	Chesham and Amersham	809	339	316	52	43	0	0	0	1,559
Chiltern	Amersham Town	3,339	Chesham and Amersham	1,418	625	596	97	81	0	0	0	2,817
Chiltern	Amersham-on-the-Hill	3,520	Chesham and Amersham	1,716	626	487	49	79	0	0	0	2,957
Chiltern	Asheridge Vale and Lowndes	3,580	Chesham and Amersham	1,434	679	634	44	74	0	0	0	2,865
Chiltern	Ashley Green, Latimer and Chenies	1,725	Chesham and Amersham	814	220	222	21	29	0	0	0	1,306
Chiltern	Austenwood	1,646	Chesham and Amersham	842	200	199	39	30	0	0	0	1,310
Chiltern	Ballinger, South Heath and Chartridge	1,703	Chesham and Amersham	691	242	270	48	81	0	0	0	1,332
Chiltern	Central	3,091	Chesham and Amersham	1,788	462	203	94	61	0	0	0	2,608
Chiltern	Chalfont Common	3,075	Chesham and Amersham	1,538	409	273	77	51	0	0	0	2,348
Chiltern	Chalfont St Giles	5,202	Chesham and Amersham	2,986	675	367	139	97	0	0	0	4,264
Chiltern	Chesham Bois and Weedon Hill	3,831	Chesham and Amersham	2,011	573	352	80	77	0	0	0	3,093
Chiltern	Cholesbury, The Lee and Bellingdon	1,837	Chesham and Amersham	902	228	162	46	34	0	0	0	1,372
Chiltern	Gold Hill	1,582	Chesham and Amersham	767	319	137	51	33	0	0	0	1,307
Chiltern	Great Missenden	1,693	Chesham and Amersham	950	246	133	27	38	0	0	0	1,394
Chiltern	Hilltop and Townsend	3,330	Chesham and Amersham	1,279	737	454	97	163	0	0	0	2,730
Chiltern	Holmer Green	3,279	Chesham and Amersham	1,682	436	186	41	50	0	0	0	2,395
Chiltern	Little Chalfont	3,815	Chesham and Amersham	1,690	628	366	96	71	0	0	0	2,851
Chiltern	Little Missenden	1,869	Chesham and Amersham	1,086	230	114	23	33	0	0	0	1,486
Chiltern	Newtown	1,701	Chesham and Amersham	702	523	145	23	92	0	0	0	1,485
Chiltern	Penn and Coleshill	3,450	Chesham and Amersham	2,085	345	187	38	55	0	0	0	2,710
Chiltern	Prestwood and Heath End	5,029	Chesham and Amersham	2,652	702	369	138	96	0	0	0	3,957
Chiltern	Ridgeway	1,782	Chesham and Amersham	749	452	281	30	43	0	0	0	1,555
Chiltern	Seer Green	1,721	Chesham and Amersham	932	239	131	48	32	0	0	0	1,382
Chiltern	St Mary's and Waterside	3,444	Chesham and Amersham	1,407	834	378	103	184	0	0	0	2,906
Chiltern	Vale	1,451	Chesham and Amersham	584	404	219	23	32	0	0	0	1,262
	Total	68,560		33,514	11,373	7,181	1,524	1,659	0	0	0	55,251

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

New seat: Chesham and Amersham

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: Chesham and Amersham
Chiltern	Amersham Common	2,017	Chesham and Amersham	809	339	316	52	43	0	0	0	1,559
Chiltern	Amersham Town	3,644	Chesham and Amersham	1,418	625	596	97	81	0	0	0	2,817
Chiltern	Amersham-on-the-Hill	3,826	Chesham and Amersham	1,716	626	487	49	79	0	0	0	2,957
Chiltern	Asheridge Vale and Lowndes	3,707	Chesham and Amersham	1,434	679	634	44	74	0	0	0	2,865
Chiltern	Ashley Green, Latimer and Chenies	1,688	Chesham and Amersham	814	220	222	21	29	0	0	0	1,306
Chiltern	Austenwood	1,696	Chesham and Amersham	842	200	199	39	30	0	0	0	1,310
Chiltern	Ballinger, South Heath and Chartridge	1,721	Chesham and Amersham	691	242	270	48	81	0	0	0	1,332
Chiltern	Central	3,374	Chesham and Amersham	1,788	462	203	94	61	0	0	0	2,608
Chiltern	Chalfont Common	3,039	Chesham and Amersham	1,538	409	273	77	51	0	0	0	2,348
Chiltern	Chalfont St Giles	5,515	Chesham and Amersham	2,986	675	367	139	97	0	0	0	4,264
Chiltern	Chesham Bois and Weedon Hill	4,000	Chesham and Amersham	2,011	573	352	80	77	0	0	0	3,093
Chiltern	Cholesbury, The Lee and Bellingdon	1,774	Chesham and Amersham	902	228	162	46	34	0	0	0	1,372
Chiltern	Gold Hill	1,691	Chesham and Amersham	767	319	137	51	33	0	0	0	1,307
Chiltern	Great Missenden	1,801	Chesham and Amersham	950	246	133	27	38	0	0	0	1,394
Chiltern	Hilltop and Townsend	3,531	Chesham and Amersham	1,279	737	454	97	163	0	0	0	2,730
Chiltern	Holmer Green	3,098	Chesham and Amersham	1,682	436	186	41	50	0	0	0	2,395
Chiltern	Little Chalfont	3,687	Chesham and Amersham	1,690	628	366	96	71	0	0	0	2,851
Chiltern	Little Missenden	1,923	Chesham and Amersham	1,086	230	114	23	33	0	0	0	1,486
Chiltern	Newtown	1,921	Chesham and Amersham	702	523	145	23	92	0	0	0	1,485
Chiltern	Penn and Coleshill	3,504	Chesham and Amersham	2,085	345	187	38	55	0	0	0	2,710
Chiltern	Prestwood and Heath End	5,118	Chesham and Amersham	2,652	702	369	138	96	0	0	0	3,957
Chiltern	Ridgeway	2,011	Chesham and Amersham	749	452	281	30	43	0	0	0	1,555
Chiltern	Seer Green	1,789	Chesham and Amersham	932	239	131	48	32	0	0	0	1,382
Chiltern	St Mary's and Waterside	3,759	Chesham and Amersham	1,407	834	378	103	184	0	0	0	2,906
Chiltern	Vale	1,631	Chesham and Amersham	584	404	219	23	32	0	0	0	1,262
Wycombe	Greater Hughenden	6,398	Aylesbury	3,192	894	291	46	83	0	0	48	4,554
Wycombe	Lacey Green, Speen and the Hampdens	2,159	Aylesbury	1,172	256	62	11	27	0	0	9	1,537
	Total	80,022		37,878	12,523	7,534	1,581	1,769	0	0	57	61,342

And these are the implied results for 2017 for the new seat of Chesham and Amersham. 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:	Cheryl Gillan (CON)
County/Area:	Buckinghamshire (South East)
Electorate:	80,022
Turnout:	76.7%

Chesham and Amersham: New Boundaries 2018 Calculation

Chesham and Amersham: Overview

Introduction