New Seat Details - Monmouthshire

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Monmouthshire 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	29,401	52.9%
LAB	20,573	37.0%
LIB	2,101	3.8%
Plaid	1,566	2.8%
UKIP	994	1.8%
Green	859	1.5%
OTH	117	0.2%
CON Majority	8,828	15.9%

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.

Monmouthshire: Map

List of old seats forming part of Monmouthshire

Old seat: Monmouth

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

Old seat: Monmouth				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	Plaid Votes	MIN Votes	OTH Votes	Total Votes
Monmouthshire	Caerwent	1,615	Monmouthshire	692	313	20	14	14	23	0	0	1,076
Monmouthshire	Cantref	1,579	Monmouthshire	684	423	41	16	21	22	0	0	1,207
Monmouthshire	Castle	1,507	Monmouthshire	642	376	86	19	22	26	0	0	1,171
Monmouthshire	Croesonen	1,607	Monmouthshire	442	788	40	20	23	23	0	0	1,336
Monmouthshire	Crucorney	1,691	Monmouthshire	791	372	29	18	22	45	0	0	1,277
Monmouthshire	Devauden	1,174	Monmouthshire	611	179	55	10	13	19	0	0	887
Monmouthshire	Dixton with Osbaston	1,793	Monmouthshire	792	393	164	24	33	33	0	0	1,439
Monmouthshire	Drybridge	2,423	Monmouthshire	930	850	71	31	91	127	0	0	2,100
Monmouthshire	Goetre Fawr	1,833	Monmouthshire	987	355	34	19	21	24	0	0	1,440
Monmouthshire	Grofield	1,285	Monmouthshire	433	473	120	20	26	33	0	0	1,105
Monmouthshire	Lansdown	1,540	Monmouthshire	392	817	44	21	22	18	0	0	1,314
Monmouthshire	Larkfield	1,475	Monmouthshire	542	412	114	24	24	39	0	0	1,155
Monmouthshire	Llanbadoc	1,014	Monmouthshire	468	232	18	11	15	19	0	0	763
Monmouthshire	Llanelly Hill	3,014	Monmouthshire	1,211	767	74	40	46	182	0	0	2,320
Monmouthshire	Llanfoist Fawr	1,616	Monmouthshire	758	324	26	16	20	19	0	0	1,163
Monmouthshire	Llangybi Fawr	1,439	Monmouthshire	793	230	17	12	15	32	0	0	1,099
Monmouthshire	Llanover	1,717	Monmouthshire	887	386	16	13	17	16	0	0	1,335
Monmouthshire	Llantilio Crossenny	1,422	Monmouthshire	721	225	18	11	15	33	0	0	1,023
Monmouthshire	Llanwenarth Ultra	1,073	Monmouthshire	352	404	19	12	13	14	0	0	814
Monmouthshire	Mardy	1,331	Monmouthshire	548	312	69	18	20	41	0	0	1,008
Monmouthshire	Mitchel Troy	953	Monmouthshire	537	161	15	8	10	22	0	0	753
Monmouthshire	Overmonnow	1,509	Monmouthshire	648	615	52	19	27	35	0	0	1,396
Monmouthshire	Portskewett	1,684	Monmouthshire	675	481	29	19	18	36	0	0	1,258
Monmouthshire	Priory	1,437	Monmouthshire	526	494	97	21	22	30	0	0	1,190
Monmouthshire	Raglan	1,510	Monmouthshire	697	369	27	17	18	28	0	0	1,156
Monmouthshire	Shirenewton	1,754	Monmouthshire	815	369	61	18	25	27	0	0	1,315
Monmouthshire	St Arvans	1,253	Monmouthshire	695	203	18	10	14	15	0	0	955
Monmouthshire	St Christopher's	1,762	Monmouthshire	556	860	52	25	27	41	0	0	1,561
Monmouthshire	St Kingsmark	2,226	Monmouthshire	1,144	420	147	24	31	29	0	0	1,795
Monmouthshire	St Mary's	1,414	Monmouthshire	482	528	113	21	28	48	0	0	1,220
Monmouthshire	Thornwell	1,860	Monmouthshire	608	873	46	26	23	37	0	0	1,613
Monmouthshire	Trellech United	2,122	Monmouthshire	1,065	422	37	20	28	40	0	0	1,612
Monmouthshire	Usk	1,862	Monmouthshire	1,141	391	65	22	32	32	0	0	1,683
Monmouthshire	Wyesham	1,644	Monmouthshire	620	489	46	19	63	35	0	0	1,272
Torfaen	Croesyceiliog North	2,580	Torfaen	752	1,124	66	34	33	29	0	0	2,038
Torfaen	Croesyceiliog South	1,420	Torfaen	434	531	30	42	17	23	0	0	1,077
Torfaen	Llanyrafon North	1,492	Torfaen	423	668	47	22	20	17	0	0	1,197
Torfaen	Llanyrafon South	2,099	Torfaen	915	578	43	27	24	27	0	0	1,614
	Total	62,729		26,409	18,207	2,066	763	953	1,339	0	0	49,737

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

Old seat: Newport East

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

Old seat: Newport East				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	Plaid Votes	MIN Votes	OTH Votes	Total Votes
Monmouthshire	Caldicot Castle	1,736	Monmouthshire	382	429	16	25	0	48	0	4	904
Monmouthshire	Dewstow	1,370	Monmouthshire	274	545	14	31	0	51	0	16	931
Monmouthshire	Green Lane	1,363	Monmouthshire	311	520	16	30	0	27	0	16	920
Monmouthshire	Mill	2,242	Monmouthshire	697	498	17	38	0	20	0	14	1,284
Monmouthshire	Rogiet	1,303	Monmouthshire	341	403	42	32	0	26	0	13	857
Monmouthshire	Severn	1,269	Monmouthshire	256	490	15	25	0	40	0	9	835
Monmouthshire	The Elms	2,408	Monmouthshire	828	659	23	45	0	35	0	16	1,606
Monmouthshire	West End	1,438	Monmouthshire	273	591	15	30	0	25	0	18	952
Newport	Alway	5,427	Newport	1,034	2,619	86	123	0	45	0	10	3,917
Newport	Beechwood	5,353	Newport	1,135	2,026	140	125	0	70	0	10	3,506
Newport	Langstone	3,620	Monmouthshire	1,370	597	43	59	0	26	0	4	2,099
Newport	Liswerry	7,897	Newport	1,792	3,671	87	179	0	81	0	15	5,825
Newport	Llanwern	2,645	Monmouthshire	784	535	20	41	0	25	0	7	1,412
Newport	Ringland	5,732	Newport	1,077	2,683	115	136	0	34	0	14	4,059
Newport	St Julians	5,876	Newport	1,279	2,334	187	149	0	95	0	12	4,056
Newport	Victoria	4,280	Newport	967	2,205	130	113	0	233	0	10	3,658
	Total	53,959		12,800	20,805	966	1,181	0	881	0	188	36,821

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

New seat: Monmouthshire

District	Ward	Electorate 2017	Old Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	Plaid Votes	MIN Votes	OTH Votes	Total Votes
New seat: Monmouthshire
Monmouthshire	Caerwent	1,404	Monmouth	692	313	20	14	14	23	0	0	1,076
Monmouthshire	Caldicot Castle	1,404	Newport East	382	429	16	25	0	48	0	4	904
Monmouthshire	Cantref	1,574	Monmouth	684	423	41	16	21	22	0	0	1,207
Monmouthshire	Castle	1,528	Monmouth	642	376	86	19	22	26	0	0	1,171
Monmouthshire	Croesonen	1,744	Monmouth	442	788	40	20	23	23	0	0	1,336
Monmouthshire	Crucorney	1,667	Monmouth	791	372	29	18	22	45	0	0	1,277
Monmouthshire	Devauden	1,158	Monmouth	611	179	55	10	13	19	0	0	887
Monmouthshire	Dewstow	1,445	Newport East	274	545	14	31	0	51	0	16	931
Monmouthshire	Dixton with Osbaston	1,879	Monmouth	792	393	164	24	33	33	0	0	1,439
Monmouthshire	Drybridge	2,741	Monmouth	930	850	71	31	91	127	0	0	2,100
Monmouthshire	Goetre Fawr	1,881	Monmouth	987	355	34	19	21	24	0	0	1,440
Monmouthshire	Green Lane	1,430	Newport East	311	520	16	30	0	27	0	16	920
Monmouthshire	Grofield	1,442	Monmouth	433	473	120	20	26	33	0	0	1,105
Monmouthshire	Lansdown	1,715	Monmouth	392	817	44	21	22	18	0	0	1,314
Monmouthshire	Larkfield	1,505	Monmouth	542	412	114	24	24	39	0	0	1,155
Monmouthshire	Llanbadoc	996	Monmouth	468	232	18	11	15	19	0	0	763
Monmouthshire	Llanelly Hill	3,029	Monmouth	1,211	767	74	40	46	182	0	0	2,320
Monmouthshire	Llanfoist Fawr	1,518	Monmouth	758	324	26	16	20	19	0	0	1,163
Monmouthshire	Llangybi Fawr	1,433	Monmouth	793	230	17	12	15	32	0	0	1,099
Monmouthshire	Llanover	1,742	Monmouth	887	386	16	13	17	16	0	0	1,335
Monmouthshire	Llantilio Crossenny	1,336	Monmouth	721	225	18	11	15	33	0	0	1,023
Monmouthshire	Llanwenarth Ultra	1,063	Monmouth	352	404	19	12	13	14	0	0	814
Monmouthshire	Mardy	1,314	Monmouth	548	312	69	18	20	41	0	0	1,008
Monmouthshire	Mill	1,998	Newport East	697	498	17	38	0	20	0	14	1,284
Monmouthshire	Mitchel Troy	982	Monmouth	537	161	15	8	10	22	0	0	753
Monmouthshire	Overmonnow	1,821	Monmouth	648	615	52	19	27	35	0	0	1,396
Monmouthshire	Portskewett	1,643	Monmouth	675	481	29	19	18	36	0	0	1,258
Monmouthshire	Priory	1,556	Monmouth	526	494	97	21	22	30	0	0	1,190
Monmouthshire	Raglan	1,508	Monmouth	697	369	27	17	18	28	0	0	1,156
Monmouthshire	Rogiet	1,332	Newport East	341	403	42	32	0	26	0	13	857
Monmouthshire	Severn	1,297	Newport East	256	490	15	25	0	40	0	9	835
Monmouthshire	Shirenewton	1,715	Monmouth	815	369	61	18	25	27	0	0	1,315
Monmouthshire	St Arvans	1,245	Monmouth	695	203	18	10	14	15	0	0	955
Monmouthshire	St Christopher's	2,037	Monmouth	556	860	52	25	27	41	0	0	1,561
Monmouthshire	St Kingsmark	2,343	Monmouth	1,144	420	147	24	31	29	0	0	1,795
Monmouthshire	St Mary's	1,592	Monmouth	482	528	113	21	28	48	0	0	1,220
Monmouthshire	The Elms	2,497	Newport East	828	659	23	45	0	35	0	16	1,606
Monmouthshire	Thornwell	2,106	Monmouth	608	873	46	26	23	37	0	0	1,613
Monmouthshire	Trellech United	2,105	Monmouth	1,065	422	37	20	28	40	0	0	1,612
Monmouthshire	Usk	2,196	Monmouth	1,141	391	65	22	32	32	0	0	1,683
Monmouthshire	West End	1,481	Newport East	273	591	15	30	0	25	0	18	952
Monmouthshire	Wyesham	1,662	Monmouth	620	489	46	19	63	35	0	0	1,272
Newport	Langstone	3,263	Newport East	1,370	597	43	59	0	26	0	4	2,099
Newport	Llanwern	2,194	Newport East	784	535	20	41	0	25	0	7	1,412
	Total	75,521		29,401	20,573	2,101	994	859	1,566	0	117	55,611

And these are the implied results for 2017 for the new seat of Monmouthshire. 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:	David Davies (CON)
County/Area:	Gwent (Wales)
Electorate:	75,521
Turnout:	73.6%

Monmouthshire: New Boundaries 2018 Calculation

Monmouthshire: Overview

Introduction