New Seat Details - Islington South and Finsbury

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Islington South and Finsbury 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	35,233	64.2%
CON	10,810	19.7%
LIB	6,285	11.4%
Green	1,468	2.7%
UKIP	1,032	1.9%
OTH	81	0.1%
LAB Majority	24,423	44.5%

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.

Islington South and Finsbury: Map

List of old seats forming part of Islington South and Finsbury

Old seat: Islington North

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

Old seat: Islington 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
Islington	Finsbury Park	9,184	Finsbury Park and Stoke Newington	752	5,954	512	35	295	0	0	61	7,609
Islington	Highbury East	8,102	Finsbury Park and Stoke Newington	888	4,056	861	90	263	0	0	30	6,188
Islington	Highbury West	10,748	Finsbury Park and Stoke Newington	1,261	5,715	608	33	333	0	0	41	7,991
Islington	Hillrise	7,912	Finsbury Park and Stoke Newington	716	4,459	731	39	245	0	0	34	6,224
Islington	Junction	7,888	Camden and St Pancras	894	4,689	465	36	267	0	0	55	6,406
Islington	Mildmay	8,541	Islington South and Finsbury	886	5,045	476	102	271	0	0	81	6,861
Islington	St George's	8,011	Camden and St Pancras	768	4,699	784	36	267	0	0	32	6,586
Islington	Tollington	8,822	Finsbury Park and Stoke Newington	705	5,469	510	42	288	0	0	49	7,063
	Total	69,208		6,870	40,086	4,947	413	2,229	0	0	383	54,928

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

Old seat: Islington South and Finsbury

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

Old seat: Islington South and Finsbury				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
Islington	Barnsbury	7,705	Islington South and Finsbury	1,341	3,591	598	82	142	0	0	0	5,754
Islington	Bunhill	8,444	Islington South and Finsbury	1,518	4,054	700	279	165	0	0	0	6,716
Islington	Caledonian	8,301	Islington South and Finsbury	1,285	4,362	632	104	156	0	0	0	6,539
Islington	Canonbury	8,039	Islington South and Finsbury	1,127	3,434	901	94	136	0	0	0	5,692
Islington	Clerkenwell	7,084	Islington South and Finsbury	1,026	3,242	913	89	145	0	0	0	5,415
Islington	Holloway	9,633	Islington South and Finsbury	1,054	4,888	831	116	175	0	0	0	7,064
Islington	St Mary's	7,800	Islington South and Finsbury	1,255	3,348	623	81	141	0	0	0	5,448
Islington	St Peter's	7,923	Islington South and Finsbury	1,318	3,269	611	85	137	0	0	0	5,420
	Total	64,929		9,924	30,188	5,809	930	1,197	0	0	0	48,048

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

New seat: Islington South and Finsbury

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: Islington South and Finsbury
Islington	Barnsbury	8,327	Islington South and Finsbury	1,341	3,591	598	82	142	0	0	0	5,754
Islington	Bunhill	9,719	Islington South and Finsbury	1,518	4,054	700	279	165	0	0	0	6,716
Islington	Caledonian	9,463	Islington South and Finsbury	1,285	4,362	632	104	156	0	0	0	6,539
Islington	Canonbury	8,237	Islington South and Finsbury	1,127	3,434	901	94	136	0	0	0	5,692
Islington	Clerkenwell	7,835	Islington South and Finsbury	1,026	3,242	913	89	145	0	0	0	5,415
Islington	Holloway	10,224	Islington South and Finsbury	1,054	4,888	831	116	175	0	0	0	7,064
Islington	Mildmay	9,346	Islington North	886	5,045	476	102	271	0	0	81	6,861
Islington	St Mary's	7,884	Islington South and Finsbury	1,255	3,348	623	81	141	0	0	0	5,448
Islington	St Peter's	7,845	Islington South and Finsbury	1,318	3,269	611	85	137	0	0	0	5,420
	Total	78,880		10,810	35,233	6,285	1,032	1,468	0	0	81	54,909

And these are the implied results for 2017 for the new seat of Islington South and Finsbury. 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:	Emily Thornberry (LAB)
County/Area:	Islington (London)
Electorate:	78,880
Turnout:	69.6%

Islington South and Finsbury: New Boundaries 2018 Calculation

Islington South and Finsbury: Overview

Introduction