New Seat Details - Lanarkshire South West

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Lanarkshire South West 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
SNP	20,431	38.9%
LAB	16,479	31.4%
CON	13,407	25.6%
LIB	1,562	3.0%
UKIP	581	1.1%
SNP Majority	3,952	7.5%

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.

Lanarkshire South West: Map

List of old seats forming part of Lanarkshire South West

Old seat: East Kilbride, Strathaven and Lesmahagow

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

Old seat: East Kilbride, Strathaven and Lesmahagow				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	SNP Votes	MIN Votes	OTH Votes	Total Votes
South Lanarkshire	Avondale and Stonehouse	12,446	Lanarkshire South West	2,465	2,075	207	93	0	3,557	0	0	8,397
South Lanarkshire	Clydesdale North	54	Dumfriesshire and Lanarkshire South East	11	12	1	0	0	12	0	0	36
South Lanarkshire	Clydesdale South	7,335	Lanarkshire Mid; Lanarkshire South West	1,184	1,854	103	121	0	1,925	0	0	5,187
South Lanarkshire	East Kilbride Central North	14,162	Lanarkshire South West	2,190	3,380	304	109	0	3,663	0	0	9,646
South Lanarkshire	East Kilbride Central South	11,181	Lanarkshire South West	1,541	2,860	285	88	0	2,907	0	0	7,681
South Lanarkshire	East Kilbride East	9,780	Lanarkshire South West	1,465	2,319	247	79	0	2,529	0	0	6,639
South Lanarkshire	East Kilbride South	11,698	Lanarkshire South West	1,780	2,614	260	73	0	3,534	0	0	8,261
South Lanarkshire	East Kilbride West	12,550	Lanarkshire South West	3,069	2,043	183	64	0	2,897	0	0	8,256
	Total	79,206		13,705	17,157	1,590	627	0	21,024	0	0	54,103

Old seat: Lanark and Hamilton East

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

Old seat: Lanark and Hamilton East				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	SNP Votes	MIN Votes	OTH Votes	Total Votes
South Lanarkshire	Avondale and Stonehouse	835	Lanarkshire South West	224	134	17	6	0	250	0	0	631
South Lanarkshire	Bothwell and Uddingston	10,040	Lanarkshire Mid	2,441	1,655	129	46	0	1,952	0	0	6,223
South Lanarkshire	Clydesdale East	3,324	Dumfriesshire and Lanarkshire South East	1,032	381	50	13	0	844	0	0	2,320
South Lanarkshire	Clydesdale North	11,639	Dumfriesshire and Lanarkshire South East	2,631	2,318	183	54	0	2,442	0	0	7,628
South Lanarkshire	Clydesdale South	608	Lanarkshire Mid	112	122	8	8	0	131	0	0	381
South Lanarkshire	Clydesdale West	14,815	Dumfriesshire and Lanarkshire South East	3,078	3,138	294	125	0	3,263	0	0	9,898
South Lanarkshire	Hamilton North and East	9,137	Lanarkshire Mid	1,775	1,949	148	52	0	2,101	0	0	6,025
South Lanarkshire	Hamilton South	10,495	Lanarkshire Mid	2,052	2,738	160	64	0	2,185	0	0	7,199
South Lanarkshire	Hamilton West and Earnock	633	Lanarkshire West	137	167	15	7	0	167	0	0	493
South Lanarkshire	Larkhall	14,334	Lanarkshire Mid	2,694	3,482	210	176	0	3,109	0	0	9,671
	Total	75,860		16,176	16,084	1,214	551	0	16,444	0	0	50,469

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

New seat: Lanarkshire South West

District	Ward	Electorate 2017	Old Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	SNP Votes	MIN Votes	OTH Votes	Total Votes
New seat: Lanarkshire South West
South Lanarkshire	Avondale and Stonehouse	12,487	East Kilbride, Strathaven and Lesmahagow	2,465	2,075	207	93	0	3,557	0	0	8,397
South Lanarkshire	Avondale and Stonehouse	966	Lanark and Hamilton East	224	134	17	6	0	250	0	0	631
South Lanarkshire	Clydesdale South	4,383	East Kilbride, Strathaven and Lesmahagow	673	1,054	59	69	0	1,094	0	0	2,949
South Lanarkshire	East Kilbride Central North	14,342	East Kilbride, Strathaven and Lesmahagow	2,190	3,380	304	109	0	3,663	0	0	9,646
South Lanarkshire	East Kilbride Central South	11,420	East Kilbride, Strathaven and Lesmahagow	1,541	2,860	285	88	0	2,907	0	0	7,681
South Lanarkshire	East Kilbride East	9,871	East Kilbride, Strathaven and Lesmahagow	1,465	2,319	247	79	0	2,529	0	0	6,639
South Lanarkshire	East Kilbride South	12,282	East Kilbride, Strathaven and Lesmahagow	1,780	2,614	260	73	0	3,534	0	0	8,261
South Lanarkshire	East Kilbride West	12,274	East Kilbride, Strathaven and Lesmahagow	3,069	2,043	183	64	0	2,897	0	0	8,256
	Total	78,025		13,407	16,479	1,562	581	0	20,431	0	0	52,460

And these are the implied results for 2017 for the new seat of Lanarkshire South West. 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:	Lisa Cameron (SNP)
County/Area:	Ayrshire and Lanark (Scotland)
Electorate:	78,025
Turnout:	67.2%

Lanarkshire South West: New Boundaries 2018 Calculation

Lanarkshire South West: Overview

Introduction