The UK General Election of 2015

Patrick Dunleavy

Briefing for Institute of Governance and Policy Analysis seminar,

University of Canberra, 23 April 2015

The 2015 party system, in England

Conservative

centre

Labour Lib

Dems

BNP Greens

UKIP

left right

Respect

Longer term view of the English top five parties – taking out ‘noise’ and opinion poll differences

Con Lab LD SNP

S. Greens UKIP

The changing Scottish party

system in 2015

left centre right

Credit: www.Scotcen.org.uk

Current party performance across both

party systems

Polling averages as at 27 April, 2015, last six polls

Will the 2015 general election mark the ‘bitter end’ for political scientists’

Belief in Duverger’s Law?

Duverger’s Law in full effect: US House of Representatives election, 2006

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Republican lead over Democrats in each electoral district

To

tal v

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ies

in

ea

ch

ele

cto

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istr

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Double APT

Crown

Republicans ahead of DemocratsDemocrats ahead of Republicans

67%67%

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Conservatives lead over Labour in each local seat (%)

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(%

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Conservative MPs

with a local majority

Labour MPs with

a local majority

Other MPs

with a local

majority

Duverger’s Law working pretty well: the general election, Great Britain 1955

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Conservative lead over Labour in each local seat (%)

To

tal vo

te s

hare

fo

r all o

ther

part

ies in

each

seat

(%)

Labour MPs with

a local majority

Conservative MPs

with a local majority

Other MPs

with a local

majority

67% 67%

Duverger’s Law not working at all: the general election, Great Britain 2010

Duverger’s Law refuted , Great Britain 2015 (predicted outcome)

Making a coalition government in the UK

The UK general election of 2010 and the coalition outcome

Party

Another

resource

% Votes

Key

resource

% of all

MPs

% coalitional

potential score

(normalized

Banzahf index)

Conservative 36.1 47.6 36.7

Labour 29.0 40.0 22.0

Liberal Democrat 23.0 8.8 22.0

Democratic Unionists 0.6 1.2 7.3

Scottish National Party 1.7 0.9 5.5

Plaid Cymru 0.6 0.5 1.8

Social Dem & Lab P

(NI) 0.4 0.5 1.8

Green 1.0 0.2 0.9

Alliance Party (NI) 0.1 0.2 0.9

Others (no seats) 7.5 0.2 0.9

Total 100% 100 % 100 %

Con share of Con + Lib Dem C score = 56%

Party Low CENTRAL High

CON 243 284 325

LAB 234 276 321

SNP 26 41 53

LIB DEM 15 25 35

Plaid Cymru 1 3 5

Greens 0 1 2

UKIP 0 1 1

The range of possible party MP numbers from Electionforecast.co.uk

Not shown: 18 Northern Ireland seats - An overall majority needs 323 seats

Party MPs % of MPs Coalitionality score %

CON 284 44.0 33.2

LAB 276 42.7 28.4

SNP 41 6.7 28.1

LIB DEM 25 3.9 2.6

Plaid Cymru 3 0.5 1

Greens 1 0.2 0.1

UKIP 1 0.2 0.1

Party coalitionality scores from MPs in Electionforecast.com central projection

Not shown: 18 Northern Ireland parties - An overall majority needs 323 seats

Party MPs % of MPs

Coalitionality score %

CON 288 44.6 36.7

LAB 263 40.7 23.3

SNP 51 7.9 23.3

LIB DEM 24 3.7 6.6

Plaid Cymru 3 0.5 1

Greens 1 0.2 0.1

UKIP 1 0.2 0.1

Party coalitionality scores from MPs in ElectionsEtc.com projection

Not shown: 18 Northern Ireland parties - An overall majority needs 323 seats

Who may have an overall majority & probabilities from ElectionsEtc.com team (Fisher)

Inner circle shows probability of being Largest party

Source: Elections etc.com

For more discussion on UK, see these LSE blogs:

http://blogs.lse.ac.uk/politicsandpolicy/

www.EUROPP.eu

www.DemocraticAudit.com