The UK Party System and Party Politics Part 1: The ... · The UK Party System and Party Politics...

35
The UK Party System and Party Politics Part 1: The electoral dimension Patrick Dunleavy Gv 311: British Politics course, Lecture 9 Michaelmas Term 2014-15 London School of Economics © P. Dunleavy 2014

Transcript of The UK Party System and Party Politics Part 1: The ... · The UK Party System and Party Politics...

The UK Party System and Party Politics

Part 1: The electoral dimension

Patrick Dunleavy

Gv 311: British Politics course, Lecture 9 Michaelmas Term 2014-15

•London School of Economics © P. Dunleavy 2014

A ‘party system’ is constituted by

a. How voters behave

b. Electoral institution effects, favouring one or more parties over others

c. Party ideologies and cleavages

d. Governance institutions favouring some parties

e. How parties recruit elites and how they behave in office and opposition

f. How much parties shape public policies

This week I cover

1. Duverger’s Law, and how it completely ceased to apply in the UK

2. Current trends and characterizing the GB party system now

3. The role of disproportionality (measured as DV scores) in sustaining major party dominance at general elections

4. Tracking party system expansion with the effective number of parties (ENP)

• Plurality rule (‘first past the post’) elections always produce/ tend to encourage the emergence of a two-party system. Formulated in 1955 at height of post-war re-growth period.

• Initially framed at national level, but that pattern soon collapsed

• Then re-framed to apply only within local electoral districts (constituencies)

• Supplementary Duverger’s Hypothesis – proportional systems encourage more parties to emerge and survive

Duverger’s Law

Source: Dunleavy and Diwakar, 2013. Analysing multiparty competition in plurality rule elections, Party Politics, vol 19: p.855

‘Mechanical’ and ‘psychological’ mechanisms in Duverger’s Law

• Andrew Cox’s 1997 reformulation says – for any electoral system the maximum number of parties per district N = M + 1 (where M is district magnitude).

• In plurality rule, M size = 1, so UK maximum number of (effective or major?) parties per constituency should = 2

• Nationalization of parties is a separate issue driven by regional identities etc – so Cox’s theoretical max N for UK could be 646 x 2 = 1292. A pretty safe bet here!

Duverger’s Law updated

• Under plurality rule, a social group with 67%+ support in a constituency can split two ways, knowing they will still always beat the opposition

• Splitting majority vote is rational in maximizing the welfare of the majority of the majority – MP closer to their view

• Implies – we should never see a top party

P1 > 67%

• If opposition also splits, the majority social group may fragment further, yet still win

Dickson and Scheve (partial) counter-theory

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100To

tal vo

te f

or

all o

ther

part

ies in

each

ele

cto

ral

dis

tric

t

Top national party lead over second national party in each electoral district

Double APT

Crown

Top national party ahead of 2nd Second national party ahead of top

67% 67%

Second national

party

Topnational party

Second national party wins local majority

Top national partywins local majority

The Crown diagram

USA House of Representatives district-level outcomes 2006 election

- USA is almost the only modern super-Duvergerian two-party system

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Republican lead over Democrats in each electoral district

To

tal v

ote

fo

r a

ll o

the

r p

art

ies

in

ea

ch

ele

cto

ral d

istr

ict

Double APT

Crown

Republicans ahead of DemocratsDemocrats ahead of Republicans

67%67%

A non-Duvergerian pattern – the Indian district-level outcomes in the

2004 general election. 43 parties in Lok Sabha, 18 in coalition government

Constituency outcomes in the 1955 general election, in Great

Britain - then a predominantly two-party system

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Conservatives lead over Labour in each local seat (%)

To

tal v

ote

sh

are

fo

r a

ll o

the

r p

art

ies

(%

)

Conservative MPs

with a local majority

Labour MPs with

a local majority

Other MPs

with a local

majority

Constituency outcomes in the 2005 general election, Great Britain

Constituency outcomes in the 2010 general election, in Great Britain

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

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%

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Conservative lead over Labour in each local seat (%)

on

serv

ati

ve lead

over

Lab

ou

r in

each

lo

cal seat

(%)

Conservative MPs

with a local majority

Labour MPs with

a local majority

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Conservative MPs

with a local majority

Labour MPs with

a local majority

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Conservative MPs

with a local majority

Labour MPs with

a local majority

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Conservative MPs

with a local majority

Labour MPs with

a local majority

South-east North-west

ScotlandWales

The patterns of constituency outcomes across four different regions in the 2010 general election

Rows consistent with Duverger’s Law

Comparing with other countries

Election districts with a given number of parties receiving 1% or more of local votes

United States, House of

Representatives 2006

Indian general election 2004

Great Britain, general election

2005

One 7.8 0 0 Two 52.6 3.9 0

Three 29.0 13.8 3.5 Four 9.2 23.4 32.3 Five 0.7 26.7 41.1 Six 0.2 18.4 17.5

Seven 0.2 8.6 4.9 Eight 0.2 3.1 0.6

Nine or more 0 2.0 0 Total 100% 100% 100%

No of cases 435 546 628

The UK party system now

1. GB has not been a ‘two-party system’ since 1974 - nor a 2.5 or 3 party system since 2000

2. In terms of voting Great Britain is a standard European multi-party system

3. Voters’ multi-partism has previously been artificially suppressed by plurality rule voting at general elections

Trends in the vote shares for the top two parties and for

smaller parties, 1970 to 2010

80 79

50 50

62

4046

5348 45

3530

0

10

20

30

40

50

60

70

80

90

100

1966 1970 1974

FEB

1974

OCT

1979 1983 1987 1992 1997 2001 2005 2010

Two party (Con plus Lab) Two party lead over Rest Liberal Democrats All other parties

Note: The numbers in grey area here show the combined Conservative and Labour per cent support, minus

the combined support for the Liberal Democrats and all other parties, that is the ‘two party lead over the Rest’.

40

50

60

70

40

50

60

70

80

90

100

Com

bin

ed %

Con a

nd L

ab v

ote

s

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Election y ear

The decline of the Labour and Conservatives two party system at general elections since 1950

% o

f Seats

wh

ere

Lab

vs C

on

are

top

2 p

artie

s

1974 hung

Parliament

1983 Labour slump: SDLP

New Labour period

Source: Prof Ron Johnston, Bristol

Party running top in 2014 Euro election votes, by local authority areas

SNP

UKIP

Lab

Con

Lib Dem

Source: House of Commons Library, European Parliament Elections 2014, Research Paper 14/32, 11 June 2014. http://www.parliament.uk/business/publications/research/briefing-papers/RP14-32/european-parliament-elections-2014

% vote share

Lab Con Lib Dem

UKIP Greens Rest Lab lead

2005 36 33 23 2 1 5 + 3

2010 29.5 37 23.5 3 1 6 -7.5

2013 EP

25.5 24 7 27.5 8 8 +1.5

Polls (Nov 2014)

33 32 8 15 5 7 + 1

State of the Parties since 2005

The 2014 party system, in England

Conservative

centre

Labour Lib

Dems

BNP Greens

UKIP

left right

Respect

Con Lab LD SNP SSP Grn

The Scottish party system

UKIP

Conservative

centre

Labour Lib

Dems

BNP Greens

UKIP

left

Respect

The English party system

A lot has changed - the 2010 English party system

Conservative

centre

Labour Lib Dems

Con Lab LD SNP Grn

- the 2010 Scottish party system

BNP GREEN UKIP

UKIP

left

left

right

right

SSP

Respect

BNP

Three key motors of party system change despite the non-reform of Westminster and local voting

• Class dealignment • PR elections since 1997, introducing new

voting systems, especially the Supplementary Vote, Additional Member System, and List PR – broadening voters’ experience nationwide

• Multi-tier elections – European elections, and devolved governments in Scotland, Wales and London (+ Northern Ireland) – so-called cross-tier “contagion effects”

Occupational class

Conservative Labour Liberal

Democrat

Other

parties Total

Upper non-manual

(AB) 39 26 29 7 100%

Routine non-manual

(C1) 39 28 24 9 100%

Skilled manual (C2) 37 29 22 12 100%

Unskilled manual/ not

working (DE) 31 40 17 12 100%

Per cent of each ‘occupational class’ voting for

main parties, general election 2010

Source: Ipsos MORI (2010) ‘How Britain Voted 2010’. http://www.ipsos-mori.com/researchpublications/researcharchive/poll.aspx?oItemId=2613

DV (deviation from proportionality) score

• We calculate the differences in seats shares compared with votes shares for each party

• Add up all the scores ignoring + or - signs

• Divide by 2 to remedy double-counting

• Gives DV score • Note: Minimum DV score is 0% No maximum DV score – unless all MPs go to a party with no votes at all, which is not a democracy

Party Vote

%

Seats %

Deviation

Con 35 45 +10

Lab 30 38 +8

Lib 20 7 -13

Other 5 0 -5

Total (Ignore = or -) 36

Deviation from Proportionality

18%

‘Deviation from proportionality’ scores, 1992-2012

Practicable minimum score for any voting system is around 4%

17.4

21

22.4

20.7

22.7

0 5 10 15 20 25

1992

1997

1999 Scotland

1999 Wales

1999 Europe

2000 London

2001

2003 Scotland

2003 Wales

2004 London

2004 Europe

2005

2007 Scotland

2007 Wales

2008 London

2009 Europe

2010

2011 Scotland

2011 Wales

2012 London

Deviation from proportionality score

Plurality election

‘Deviation from proportionality’ scores, 1992-2012

Practicable minimum score for any voting system is around 4%

E

E

E

17.4

21

22.4

20.7

22.7

10.3

10.6

13.9

14.8

12.1

14.1

14.8

13.7

10.2

17.7

8.1

11.7

11.8

14.7

12.1

0 5 10 15 20 25

1992

1999 Scotland

1999 Europe

2001

2003 Wales

2004 Europe

2007 Scotland

2008 London

2010

2011 Wales

DV

score

Plurality election British AMS (PR) election

Local DV scores in the 2010 general election By Chris Hanretty (Univ of East Anglia) The darker the colour, the higher the DV score in the 30 seats around constituency X

Durham

South west

Source: Democratic Audit blog, 5/10/2013 http://www.democraticaudit.com/?p=1496

Local DV score %

Counting parties – the ENP score

• We calculate the effective number of parties (ENP) by squaring the decimal vote shares, summing and dividing 1 by the sum

• The squaring process weights the contribution of large parties highly, and marginalizes that of small parties

• Here 1 divided by 0.312 = 3.21 parties

Party Vote Vote sq

Con .38 0.144

Lab .35 0.123

Lib .20 .04

Others .07 .005

Total 0.312

‘Effective number of party’ scores since 1992

Practicable minimum score for any voting system is around 1.5 parties

0 1 2 3 4 5 6 7

1992

1999 Scotland

1999 Europe

2001

2003 Wales

2004 Europe

2007 Scotland

2008 London

2010

2011 Wales

Effective number of parties

Plurality election

2.21

3.06

2.63

3.4

3.6

3.3

3

4.7

4.2

3

5.8

4.65

4.59

4.57

3.5

4.4

3.5

0 1 2 3 4 5 6 7

1992

1999 Scotland

1999 Europe

2001

2003 Wales

2004 Europe

2007 Scotland

2008 London

2010

2011 Wales

EN

P

Plurality election British AMS (PR) election

‘Effective number of party’ scores, 1992-2012

Practicable minimum score for any voting system is around 1.5 parties

‘Effective number of party’ scores, 1992-2012

Practicable minimum score for any voting system is around 1.5 parties

2.21

3.06

2.63

3.4

3.6

3.3

3

4.7

4.2

3

5.8

4.65

4.59

4.57

3.5

4.4

3.5

4.3

5.1

6.3

0 1 2 3 4 5 6 7

1992

1999 Scotland

1999 Europe

2001

2003 Wales

2004 Europe

2007 Scotland

2008 London

2010

2011 Wales

EN

P

Plurality election British AMS (PR) election Euro election

Outcomes of the European Parliament elections in Great Britain in 1999, 2004 and 2009, using regional list PR systems

0

10

20

30

40

50

60

70

80

90

100

-100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Conservative % lead over Labour in each local seat

To

tal %

vo

te s

ha

re f

or

all o

the

r p

art

ies

in

ea

ch

lo

ca

l

se

at

2009 2004 1999

Conservatives ahead of Labour Labour ahead of Conservatives

67%67%

Crown

Thanks for listening

Next week: Party System – Ideology, Strategy,

Governance and Policy-making aspects