New Seat Details - Luton South

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Luton South 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	31,215	60.7%
CON	17,442	33.9%
LIB	1,225	2.4%
UKIP	795	1.5%
Green	537	1.0%
OTH	172	0.3%
LAB Majority	13,773	26.8%

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.

Luton South: Map

List of old seats forming part of Luton South

Old seat: Bedfordshire South West

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

Old seat: Bedfordshire South 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
Central Bedfordshire	Caddington	2,845	Luton South	1,152	399	38	0	36	0	0	13	1,638
Central Bedfordshire	Dunstable-Central	3,332	Bedfordshire South West	1,434	843	75	0	27	0	0	14	2,393
Central Bedfordshire	Dunstable-Icknield	5,731	Bedfordshire South West	2,644	1,372	126	0	42	0	0	23	4,207
Central Bedfordshire	Dunstable-Manshead	3,575	Bedfordshire South West	1,462	1,225	77	0	29	0	0	33	2,826
Central Bedfordshire	Dunstable-Northfields	6,528	Bedfordshire South West	2,761	1,920	137	0	119	0	0	37	4,974
Central Bedfordshire	Dunstable-Watling	7,402	Bedfordshire South West	3,615	1,474	131	0	52	0	0	41	5,313
Central Bedfordshire	Eaton Bray	3,292	Bedfordshire South West	1,610	539	49	0	21	0	0	19	2,238
Central Bedfordshire	Heath and Reach	3,426	Bedfordshire South West	1,643	444	47	0	18	0	0	12	2,164
Central Bedfordshire	Houghton Hall	5,717	Luton North and Houghton Regis	2,017	1,830	322	0	95	0	0	9	4,273
Central Bedfordshire	Leighton Buzzard North	10,881	Bedfordshire South West	4,608	2,480	417	0	166	0	0	20	7,691
Central Bedfordshire	Leighton Buzzard South	9,303	Bedfordshire South West	3,810	1,943	375	0	129	0	0	34	6,291
Central Bedfordshire	Linslade	9,108	Bedfordshire South West	3,754	1,948	566	0	166	0	0	13	6,447
Central Bedfordshire	Parkside	3,220	Luton North and Houghton Regis	1,344	1,241	84	0	28	0	0	18	2,715
Central Bedfordshire	Tithe Farm	2,994	Luton North and Houghton Regis	1,104	1,135	186	0	22	0	0	14	2,461
	Total	77,354		32,958	18,793	2,630	0	950	0	0	300	55,631

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

Old seat: Luton North

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

Old seat: Luton 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
Luton	Barnfield	5,295	Luton South	1,411	2,012	128	0	64	0	0	0	3,615
Luton	Bramingham	5,366	Luton North and Houghton Regis	1,683	1,569	90	0	49	0	0	0	3,391
Luton	Challney	8,227	Luton North and Houghton Regis	1,667	4,337	136	0	98	0	0	0	6,238
Luton	Icknield	5,614	Luton North and Houghton Regis	1,782	1,720	90	0	54	0	0	0	3,646
Luton	Leagrave	7,492	Luton North and Houghton Regis	1,995	3,560	41	0	67	0	0	0	5,663
Luton	Lewsey	8,207	Luton North and Houghton Regis	1,654	4,080	82	0	74	0	0	0	5,890
Luton	Limbury	5,530	Luton North and Houghton Regis	1,346	2,264	48	0	47	0	0	0	3,705
Luton	Northwell	4,966	Luton North and Houghton Regis	1,043	2,693	48	0	52	0	0	0	3,836
Luton	Saints	8,501	Luton North and Houghton Regis	1,515	5,272	31	0	82	0	0	0	6,900
Luton	Sundon Park	5,354	Luton North and Houghton Regis	1,305	2,259	114	0	62	0	0	0	3,740
	Total	64,552		15,401	29,766	808	0	649	0	0	0	46,624

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

Old seat: Luton South

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

Old seat: Luton South				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
Central Bedfordshire	Caddington	4,422	Luton South	1,469	919	22	30	39	0	0	22	2,501
Luton	Biscot	8,351	Luton South	1,372	5,059	116	92	36	0	0	52	6,727
Luton	Crawley	4,696	Luton South	1,055	1,676	106	129	18	0	0	5	2,989
Luton	Dallow	8,243	Luton South	1,279	5,338	138	44	38	0	0	28	6,865
Luton	Farley	6,839	Luton South	1,499	3,359	130	61	34	0	0	8	5,091
Luton	High Town	4,206	Luton South	1,279	2,292	62	54	79	0	0	6	3,772
Luton	Round Green	7,566	Luton South	1,984	2,616	138	69	28	0	0	8	4,843
Luton	South	6,139	Luton South	1,811	3,653	108	73	124	0	0	15	5,784
Luton	Stopsley	5,294	Luton South	1,263	1,503	99	48	18	0	0	7	2,938
Luton	Wigmore	7,985	Luton South	1,868	2,389	140	195	23	0	0	8	4,623
	Total	63,741		14,879	28,804	1,059	795	437	0	0	159	46,133

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

New seat: Luton South

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: Luton South
Central Bedfordshire	Caddington	2,347	Bedfordshire South West	1,152	399	38	0	36	0	0	13	1,638
Central Bedfordshire	Caddington	3,644	Luton South	1,469	919	22	30	39	0	0	22	2,501
Luton	Barnfield	5,181	Luton North	1,411	2,012	128	0	64	0	0	0	3,615
Luton	Biscot	9,797	Luton South	1,372	5,059	116	92	36	0	0	52	6,727
Luton	Crawley	4,353	Luton South	1,055	1,676	106	129	18	0	0	5	2,989
Luton	Dallow	9,998	Luton South	1,279	5,338	138	44	38	0	0	28	6,865
Luton	Farley	7,414	Luton South	1,499	3,359	130	61	34	0	0	8	5,091
Luton	High Town	5,493	Luton South	1,279	2,292	62	54	79	0	0	6	3,772
Luton	Round Green	7,055	Luton South	1,984	2,616	138	69	28	0	0	8	4,843
Luton	South	8,423	Luton South	1,811	3,653	108	73	124	0	0	15	5,784
Luton	Stopsley	4,279	Luton South	1,263	1,503	99	48	18	0	0	7	2,938
Luton	Wigmore	6,731	Luton South	1,868	2,389	140	195	23	0	0	8	4,623
	Total	74,715		17,442	31,215	1,225	795	537	0	0	172	51,386

And these are the implied results for 2017 for the new seat of Luton South. 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:	Gavin Shuker (LAB)
County/Area:	Bedfordshire (Anglia)
Electorate:	74,715
Turnout:	68.8%

Luton South: New Boundaries 2018 Calculation

Luton South: Overview

Introduction