Filton and Bradley Stoke: New Boundaries Calculation

Due to changes in ward boundaries, some new wards are divided among several old constituencies (though never between two new constituencies). Such wards are shown divided into several parts, called [1], [2], and so on.

Election results from a recent local election are given. This is usually the local election from 2003, 2004 or 2006. 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. Where zero votes are shown, the ward is not needed because the entire old seat is unsplit.

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.

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% of its votes from each ward. 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 on a ward-by-ward basis using these common percentages.

More details of the calculation formulas are available.

The old seat(s) needed are:

• Northavon
• Kingswood
• Bristol North West

Old seat: Northavon

					Actual Results				Turnout-adjusted Results					Transfer-adjusted Results
District	Ward	Electorate 2005	Old Seat	New Seat	CON Votes	LAB Votes	LIB Votes	OTH Votes	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes
South Gloucestershire	Almondsbury	3,047	Northavon	Filton and Bradley Stoke	858	82	503	0	1,318	126	773	0	2,217	1,272	124	747	72	2,217
South Gloucestershire	Alveston	2,489	Northavon	Thornbury and Yate	380	58	498	0	735	112	963	0	1,810	709	110	931	58	1,810
South Gloucestershire	Boyd Valley	5,639	Northavon	Thornbury and Yate	2,525	745	1,760	0	2,059	608	1,435	0	4,102	1,987	599	1,387	126	4,102
South Gloucestershire	Bradley Stoke Bowsland [2]	4,144	Northavon	Filton and Bradley Stoke	662	380	1,741	0	717	412	1,886	0	3,015	692	406	1,823	92	3,015
South Gloucestershire	Charfield	2,678	Northavon	Thornbury and Yate	221	82	592	0	481	179	1,289	0	1,949	464	176	1,246	61	1,949
South Gloucestershire	Chipping Sodbury	5,151	Northavon	Thornbury and Yate	1,898	506	2,568	0	1,431	381	1,936	0	3,748	1,381	375	1,872	118	3,748
South Gloucestershire	Cotswold Edge	2,960	Northavon	Thornbury and Yate	501	47	799	0	801	75	1,277	0	2,153	773	73	1,234	70	2,153
South Gloucestershire	Dodington	5,377	Northavon	Thornbury and Yate	545	300	1,798	0	807	444	2,661	0	3,912	779	437	2,573	121	3,912
South Gloucestershire	Frampton Cotterrell	5,086	Northavon	Thornbury and Yate	1,159	732	2,208	0	1,046	661	1,993	0	3,700	1,009	651	1,927	110	3,700
South Gloucestershire	Ladden Brook	2,914	Northavon	Thornbury and Yate	379	88	672	0	705	164	1,251	0	2,120	680	161	1,209	67	2,120
South Gloucestershire	Pilning and Severn Beach	2,801	Northavon	Filton and Bradley Stoke	384	184	470	0	754	361	923	0	2,038	727	356	892	61	2,038
South Gloucestershire	Severn	2,853	Northavon	Thornbury and Yate	1,034	27	752	0	1,184	31	861	0	2,076	1,143	30	832	69	2,076
South Gloucestershire	Thornbury North	5,437	Northavon	Thornbury and Yate	1,734	408	2,344	261	1,445	340	1,953	217	3,955	1,395	335	1,888	336	3,955
South Gloucestershire	Thornbury South	5,102	Northavon	Thornbury and Yate	1,550	496	2,132	0	1,377	441	1,894	0	3,712	1,329	434	1,831	116	3,712
South Gloucestershire	Westerleigh	2,685	Northavon	Thornbury and Yate	389	117	772	0	595	179	1,180	0	1,954	574	176	1,141	61	1,954
South Gloucestershire	Winterbourne [3]	7,136	Northavon	Filton and Bradley Stoke	5,486	833	3,989	0	2,763	420	2,009	0	5,192	2,667	414	1,942	167	5,192
South Gloucestershire	Yate Central	5,289	Northavon	Thornbury and Yate	729	461	2,048	0	866	548	2,434	0	3,848	836	540	2,353	117	3,848
South Gloucestershire	Yate North	5,555	Northavon	Thornbury and Yate	819	336	2,612	0	879	360	2,802	0	4,041	848	355	2,709	127	4,041
South Gloucestershire	Yate West	4,830	Northavon	Thornbury and Yate	494	441	2,034	0	585	522	2,407	0	3,514	564	514	2,327	106	3,514
	Total		Northavon						20,548	6,364	31,927	217	59,056	19,839	6,277	30,871	2,068	59,056

The transfer table below shows the votes cast in the old seat of Northavon at the general election, as well as the total local turnout-adjusted votes. The number of votes to transfer, shown in the fourth and fifth columns, are the difference between the general and local votes. Strong parties will have votes transferred away, and weak parties will have votes transferred into them. The final column describes how votes will be transferred away from or into that party on a ward-by-ward basis. If a party is too strong, it will lose a percentage of its votes in each ward which go into that ward's transfer pool. If a party is too weak, it will gain votes from each ward's transfer pool in proportion to the number of transfer votes it needs over the whole old seat.

Party	General Election 2005 Votes	Local Election Turnout-adjusted Votes	Votes to transfer away	Votes to transfer into	Ward Transfers needed
CON	19,839	20,548	709	0	Transfer away 3.5% (= 709 / 20548) of ward's CON votes
LAB	6,277	6,364	87	0	Transfer away 1.4% (= 87 / 6364) of ward's LAB votes
LIB	30,872	31,927	1,055	0	Transfer away 3.3% (= 1055 / 31927) of ward's LIB votes
OTH	2,068	217	0	1,851	Transfer in 100.0% (= 1851 / 1851) of ward's transfer pool votes
Total	59,056	59,056	1,851	1,851

After transfer adjustment, the totals for each party over all the wards match the general election vote in the old seat.

Old seat: Kingswood

					Actual Results				Turnout-adjusted Results					Transfer-adjusted Results
District	Ward	Electorate 2005	Old Seat	New Seat	CON Votes	LAB Votes	LIB Votes	OTH Votes	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes
City Of Bristol	Frome Vale	8,188	Kingswood	Bristol East	1,820	1,881	1,042	313	1,980	2,047	1,134	341	5,502	1,873	2,288	941	399	5,502
City Of Bristol	Hillfields	8,955	Kingswood	Bristol East	1,073	2,475	1,504	272	1,213	2,797	1,700	307	6,017	1,147	3,082	1,410	375	6,017
South Gloucestershire	Bitton [1]	821	Kingswood	Kingswood	467	255	472	0	216	118	218	0	552	204	157	180	9	552
South Gloucestershire	Downend	8,399	Kingswood	Filton and Bradley Stoke	4,576	2,405	1,357	1,581	2,603	1,368	772	899	5,642	2,462	1,586	640	951	5,642
South Gloucestershire	Hanham [1]	4,869	Kingswood	Kingswood	4,393	3,324	1,734	0	1,521	1,151	600	0	3,272	1,439	1,299	497	35	3,272
South Gloucestershire	Kings Chase	8,206	Kingswood	Kingswood	2,103	4,018	777	0	1,681	3,211	621	0	5,513	1,590	3,369	515	37	5,513
South Gloucestershire	Longwell Green [1]	4,210	Kingswood	Kingswood	2,765	990	611	0	1,791	641	396	0	2,828	1,694	772	328	31	2,828
South Gloucestershire	Parkwall	6,199	Kingswood	Kingswood	1,081	1,823	944	0	1,170	1,973	1,022	0	4,165	1,107	2,163	848	45	4,165
South Gloucestershire	Rodway	7,745	Kingswood	Kingswood	2,316	4,291	1,111	0	1,561	2,893	749	0	5,203	1,476	3,063	621	40	5,203
South Gloucestershire	Siston	12,137	Kingswood	Kingswood	5,606	3,432	4,062	0	3,489	2,136	2,528	0	8,153	3,301	2,633	2,098	119	8,153
South Gloucestershire	Staple Hill	5,591	Kingswood	Filton and Bradley Stoke	786	2,289	464	0	834	2,430	492	0	3,756	789	2,533	408	24	3,756
South Gloucestershire	Winterbourne [2]	57	Kingswood	Filton and Bradley Stoke	5,486	833	3,989	0	20	3	15	0	38	18	5	12	0	38
South Gloucestershire	Woodstock	8,439	Kingswood	Kingswood	2,068	4,360	911	0	1,598	3,368	704	0	5,670	1,511	3,533	584	39	5,670
	Total		Kingswood						19,677	24,136	10,951	1,547	56,311	18,618	26,491	9,089	2,113	56,311

The transfer table below shows the votes cast in the old seat of Kingswood at the general election, as well as the total local turnout-adjusted votes. The number of votes to transfer, shown in the fourth and fifth columns, are the difference between the general and local votes. Strong parties will have votes transferred away, and weak parties will have votes transferred into them. The final column describes how votes will be transferred away from or into that party on a ward-by-ward basis. If a party is too strong, it will lose a percentage of its votes in each ward which go into that ward's transfer pool. If a party is too weak, it will gain votes from each ward's transfer pool in proportion to the number of transfer votes it needs over the whole old seat.

Party	General Election 2005 Votes	Local Election Turnout-adjusted Votes	Votes to transfer away	Votes to transfer into	Ward Transfers needed
CON	18,618	19,677	1,059	0	Transfer away 5.4% (= 1059 / 19677) of ward's CON votes
LAB	26,491	24,136	0	2,355	Transfer in 80.6% (= 2355 / 2921) of ward's transfer pool votes
LIB	9,089	10,951	1,862	0	Transfer away 17.0% (= 1862 / 10951) of ward's LIB votes
OTH	2,113	1,547	0	566	Transfer in 19.4% (= 566 / 2921) of ward's transfer pool votes
Total	56,311	56,311	2,921	2,921

After transfer adjustment, the totals for each party over all the wards match the general election vote in the old seat.

Old seat: Bristol North West

					Actual Results				Turnout-adjusted Results					Transfer-adjusted Results
District	Ward	Electorate 2005	Old Seat	New Seat	CON Votes	LAB Votes	LIB Votes	OTH Votes	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes
City Of Bristol	Avonmouth	8,847	Bristol North West	Bristol North West	1,406	2,522	1,111	311	1,418	2,543	1,120	314	5,395	1,390	2,902	720	382	5,395
City Of Bristol	Henbury	7,323	Bristol North West	Bristol North West	1,397	2,017	1,029	0	1,404	2,027	1,034	0	4,465	1,376	2,360	665	63	4,465
City Of Bristol	Horfield [1]	7,106	Bristol North West	Bristol North West	1,543	1,887	1,230	334	1,339	1,638	1,067	290	4,334	1,312	1,980	686	354	4,334
City Of Bristol	Kingsweston [1]	5,489	Bristol North West	Bristol North West	941	1,556	1,532	429	707	1,168	1,150	322	3,347	693	1,524	739	389	3,347
City Of Bristol	Lockleaze [1]	6,637	Bristol North West	Bristol North West	488	1,542	1,880	242	476	1,503	1,833	236	4,048	466	2,060	1,178	341	4,048
City Of Bristol	Southmead	7,603	Bristol North West	Bristol North West	946	2,106	771	243	1,079	2,402	879	277	4,637	1,057	2,683	565	330	4,637
South Gloucestershire	Bradley Stoke Baileys Court	3,136	Bristol North West	Filton and Bradley Stoke	242	149	446	0	553	340	1,019	0	1,912	542	654	655	59	1,912
South Gloucestershire	Bradley Stoke Bowsland [1]	1,895	Bristol North West	Filton and Bradley Stoke	662	380	1,741	0	275	158	723	0	1,156	269	379	464	41	1,156
South Gloucestershire	Bradley Stoke Sherbourne	4,240	Bristol North West	Filton and Bradley Stoke	720	345	1,037	0	886	424	1,276	0	2,586	868	821	820	75	2,586
South Gloucestershire	Filton	7,751	Bristol North West	Filton and Bradley Stoke	2,532	3,279	1,142	139	1,688	2,186	761	93	4,728	1,654	2,442	489	141	4,728
South Gloucestershire	Patchway	8,045	Bristol North West	Filton and Bradley Stoke	1,156	2,202	2,766	137	906	1,726	2,168	107	4,907	888	2,391	1,394	233	4,907
South Gloucestershire	Stoke Gifford	8,788	Bristol North West	Filton and Bradley Stoke	4,415	2,447	2,849	0	2,437	1,351	1,572	0	5,360	2,388	1,862	1,011	97	5,360
South Gloucestershire	Winterbourne [1]	1,012	Bristol North West	Filton and Bradley Stoke	5,486	833	3,989	0	328	50	239	0	617	321	127	153	14	617
	Total		Bristol North West						13,496	17,516	14,841	1,639	47,492	13,230	22,192	9,544	2,525	47,492

The transfer table below shows the votes cast in the old seat of Bristol North West at the general election, as well as the total local turnout-adjusted votes. The number of votes to transfer, shown in the fourth and fifth columns, are the difference between the general and local votes. Strong parties will have votes transferred away, and weak parties will have votes transferred into them. The final column describes how votes will be transferred away from or into that party on a ward-by-ward basis. If a party is too strong, it will lose a percentage of its votes in each ward which go into that ward's transfer pool. If a party is too weak, it will gain votes from each ward's transfer pool in proportion to the number of transfer votes it needs over the whole old seat.

Party	General Election 2005 Votes	Local Election Turnout-adjusted Votes	Votes to transfer away	Votes to transfer into	Ward Transfers needed
CON	13,230	13,496	266	0	Transfer away 2.0% (= 266 / 13496) of ward's CON votes
LAB	22,192	17,516	0	4,676	Transfer in 84.1% (= 4676 / 5562) of ward's transfer pool votes
LIB	9,545	14,841	5,296	0	Transfer away 35.7% (= 5296 / 14841) of ward's LIB votes
OTH	2,525	1,639	0	886	Transfer in 15.9% (= 886 / 5562) of ward's transfer pool votes
Total	47,492	47,492	5,562	5,562

After transfer adjustment, the totals for each party over all the wards match the general election vote in the old seat.

New seat: Filton and Bradley Stoke

District	Ward	Electorate 2005	Old Seat	New Seat	CON Votes	LAB Votes	LIB Votes	OTH Votes	Total Votes
South Gloucestershire	Almondsbury	3,047	Northavon	Filton and Bradley Stoke	1,272	124	747	72	2,217
South Gloucestershire	Bradley Stoke Baileys Court	3,136	Bristol North West	Filton and Bradley Stoke	542	654	655	59	1,912
South Gloucestershire	Bradley Stoke Bowsland [1]	1,895	Bristol North West	Filton and Bradley Stoke	269	379	464	41	1,156
South Gloucestershire	Bradley Stoke Bowsland [2]	4,144	Northavon	Filton and Bradley Stoke	692	406	1,823	92	3,015
South Gloucestershire	Bradley Stoke Sherbourne	4,240	Bristol North West	Filton and Bradley Stoke	868	821	820	75	2,586
South Gloucestershire	Downend	8,399	Kingswood	Filton and Bradley Stoke	2,462	1,586	640	951	5,642
South Gloucestershire	Filton	7,751	Bristol North West	Filton and Bradley Stoke	1,654	2,442	489	141	4,728
South Gloucestershire	Patchway	8,045	Bristol North West	Filton and Bradley Stoke	888	2,391	1,394	233	4,907
South Gloucestershire	Pilning and Severn Beach	2,801	Northavon	Filton and Bradley Stoke	727	356	892	61	2,038
South Gloucestershire	Staple Hill	5,591	Kingswood	Filton and Bradley Stoke	789	2,533	408	24	3,756
South Gloucestershire	Stoke Gifford	8,788	Bristol North West	Filton and Bradley Stoke	2,388	1,862	1,011	97	5,360
South Gloucestershire	Winterbourne [1]	1,012	Bristol North West	Filton and Bradley Stoke	321	127	153	14	617
South Gloucestershire	Winterbourne [2]	57	Kingswood	Filton and Bradley Stoke	18	5	12	0	38
South Gloucestershire	Winterbourne [3]	7,136	Northavon	Filton and Bradley Stoke	2,667	414	1,942	167	5,192
	Total			Filton and Bradley Stoke	15,564	14,106	11,457	2,034	43,163

And these are the implied results for 2005 for the new seat of Filton and Bradley Stoke.