Proportional Electoral Systems

1
Proportional Electoral Systems
Lecture 6
German General Election 2002 The Green vote
(8.1)
2
Objectives

• (i) to establish the principles of, and
  variations in, PR electoral systems
• (ii) To learn about the relation between
  electoral system and shape of government

3
Introduction

• In contrast to UK no western European country
  operates by a first past the post rule in
  single member constituencies
• Most countries have systems based on Proportional
  Representation

4
Purpose of elections

• Representation of citizens in an assembly
• To give voice to citizens in the political arena
  (not on singles issues, but on packages)
• To create link between citizens and those in
  power
• Symbolic function gives voters the feeling of
  being represented
• Incentive for politicians to be responsive
• To reflect the plurality of interests

5
Purpose of electoral systems (for parliaments)

• Translate votes into seats
• Two conflicting targets
• avoid disproportionality (bias)
• avoid fragmentation
• No electoral system is perfectly representative

6
Electoral rules

• Cover a wide range of arrangements
• E.g. who can vote
• How people are registered as electors
• When elections are held
• How candidates are nominated
• Drawing up constituency boundaries
• Party finance
• Conduct of campaigns

7
Electoral systems

• consist of a set of rules according to which
• People cast their votes ballot structure
• The size of the electoral constituency
  constituency structure
• Votes are translated/converted into seats in
  Parliament electoral formula

8
Electoral formula

• how votes get translated into seats.
• Majoritarian the party winning the majority
  (50x) of votes wins all the seats
• Plurality the party winning the most votes wins
  all the seats.
• Proportional representation seats are allocated
  according to the percentage of votes won
  (thresholds etc.).

9
District magnitude

• the number of seats to be allocated
• Single member districts one seat only
• Multi-member districts multiple seats
• Most countries have one of two combinations
• Plurality rule plus single member districts, or
  SMP.
• PR plus multi-member districts.
• Voting in SMP systems is candidate based.
• Voting PR systems is party based. Voters vote for
  party lists, not individuals.

10
First Past the Post

• E.g. UK, USA, Canada, India, Thailand
• winner takes all simple plurality
• Leading candidate elected on first and only
  ballot
• Regarded as the simplest method of electing
  representatives
• Big parties favoured (bonus)
• Third parties disadvantaged
• Disproportionality vs fragmentation

11
FPTP case study

• Hypothetical example A country with three
  parties (X,Y,Z) and 3 districts
• District 1 X wins 60, Y wins 10, Z wins 30.
  X WINS SEAT.
• District 2 X wins 10, Y wins 60, Z wins 30.
  Y WINS SEAT.
• District 3 X wins 51, Y wins 1, Z wins 48. X
  WINS SEAT.
• Overall, Z wins NO SEATS, even though it won at
  least 30 of the vote (36 total if population
  equal in all districts)
• Y 24 of the vote, one seat

12
Malapportionment

• Voters do not want to waste their votes each
  vote should carry the same weight
• Malapportionment districts are
• Of very unequal size (in terms of electors)
• Drawn in way that favours one party
• From the parties point of view, it is crucial
  that their support is distributed efficiently
• No support in districts that they cant win
• Only enough support to win a plurality

13
Gerrymandering

• District boundaries drawn in non-obvious way to
  favour a single political party
• Packing Cracking
• Named after Massachusetts Governor E. Gerry (1812)

14
First Past the Post
UK 1951 Lab 48.8 votes 259 seats Cons 48.0
votes 321 seats UK 1974 Labour 37.1 votes 301
seats Con 37.8 votes 297 seats UK 1983
Lab 27.6 votes 32.1 seats Lib/SD 25.4
votes 3.5 seats UK 2001 Lab 41.0
votes 64 seats Cons 32.0 votes 25
seats Lib 18.0 votes 8 seats
!
!
15
The PR principle

• E.g. Israel, Scandinavia, most of continental
  Europe and Latin America
• Most states adopted PR after WWII
• Seats in parliament should reflect as closely as
  possible the distribution of opinion/policy
  preferences amongst the electorate
• Seats obtained by quota in multimember
  constituencies
• Ballot is cast for a partys list of candidates
• In some PR countries voters can express support
  for individual candidates on the list

16
origins of PR

• 4 types of explanation
• Rokkan way of dealing with ethnic heterogeneity
• Sartori device to protect liberal parties in
  face of the rising tide of socialism and the
  arrival of mass politics
• Normative argument about fairness
• Enlightenment mathematicians experimented with
  fair voting systems

Denmark 1855 Netherlands 1917 Switzerland
1891 Austria Belgium 1899 Italy Finland 1906
Germany Sweden 1907 France
1918
17
Types of PR

• In fact many different versions of PR
• Country-specific
• (Exception France has a two-ballot system)
• Three dimensions
• Ballot structure
• Constituencies
• Electoral formulae

18
Single Transferable Vote
19
Single Transferable Vote

• Often considered as a variant of PR that requires
  no list
• Voter can assign rank to each candidate
• Quota to win a seat
• E.g. 200 voters, 4 seats -gt 41 votes required
• Any candidate with at least the quota a winner
• Transfer surplus votes of winners proportionally
  according to second preferences of their voters.
  Winner(s)? Repeat, otherwise
• Eliminate candidate with fewest vote, transfer
  votes proportionally
• Used in Ireland, Malta, Australia
• PR, but no list!

20
Types of PR

• In fact many different versions of PR
• Country-specific
• (Exception France has a two-ballot system)
• Three dimensions
• Ballot structure
• Constituencies
• Electoral formulae

21
Ballot Structure

• One vote Finland, Belgium, Netherlands, Denmark
• - For candidate or party list -
• Two votes (MMS) Germany
• One for constituency candidate
• One for a party list
• As many votes as seats Luxemburg, Switzerland
• Fewer votes than seats (limited vote) Italy
  (pre-1994)
• - Variations of party list voting
  (closed/half-open/open)

?
?
?
?
?
?
?
? ? ? ? ?
?
?
22
PR MMS two votes
23
Constituencies

• Electoral unit on which seats are based
• In PR systems constituencies are relatively large
  
• More than one MP per const. (usually at least 3-5
  members, sometimes the whole country)
• Germany 50 Bundestag seats based on
  constituency vote 50 Bundestag seats based on
  party vote (PR)
• Italy (post 1994) 75 chamber of deputies based
  on constituency vote, 25 allocated by PR

24
Electoral Formulae

• Various quotas often differences very small in
  practice
• Legal thresholds to avoid fragmentation (e.g.
  five per cent in Germany)
• In countries with small constituencies (low
  number of seats) effective threshold (de facto)
  much more important
• Unless there is an upper tier for redistribution
  of votes

25
Political effects of PR

• Gives representation to small parties
• Leads to coalition governments
• Danger of fragmentation banned since introduction
  of thresholds (Weimar Republic, French 4th
  republic, post-war Italy)
• Openness easier for new parties to break through
• Fairness government can claim to have majority
  of votes
• Turnout rates higher
• Bigger choice for voters

26
How to measure proportionality?

• Abundance of measures Gallagher-Index rather
  popular
• Root of sum of squared differences between
  vote/seat share, divided by two range 0/100
• Actually a measure of disproportionality
• UK 2005
• Vote shares for Lab, Con, Lib, Others 35, 32,
  22, 10 per cent
• Seats in the Commons 55, 30, 10, 5 per cent
• GI 17 (between 1974-2002 usually between 1222)
• Index for Austria typically between 13, Germany
  between 25, Belgium around 3, France between
  2025

27
Summary PR vs FPTP

• Duvergers Law SMP systems tend to produce two
  parties, PR systems tend to produce more than two
  parties
• Mechanical effects
• Psychological effects
• CLAIM I Plurality systems produce
  disproportional results but ensure stable
  governments
• Exception France
• Claim II Plurality systems favor big parties
  (yet UK Libs survive UK Green party?)
• CLAIM III PR systems produce proportional
  results but produce unstable governments
• Exception (Netherlands), Germany