POLS2010 Chap.8 Electoral Systems and Electoral Change
Electoral Systems and Electoral Change
Week 8 has two halves. The first compares the families of electoral systems, majority and plurality rules against proportional representation, with their effects on parties, representation and turnout, then asks which way causation runs: Duverger has rules shaping parties, Colomer has parties choosing rules. It explains why parties rarely reform the rules that elected them and the two paths to reform.
The second half follows electoral change: the theory of party identification and the funnel of causality, partisan dealignment in Australia and elsewhere, the decline of class and religion, the rise of education, generation and gender, and the personalisation of politics.
Both halves feed the tutorial topic, which asks you to evaluate the advantages and disadvantages of proportional and plurality systems with reference to real countries.
The chapter therefore pairs each argument with a case: New Zealand for mixed-member proportional voting, Canada and the United States for first past the post, and Australia for dealignment.
What this chapter covers
- 01
Majority and plurality rules versus PR
- 02
Duverger’s laws and Colomer’s reversal
- 03
The Micromega rule and electoral reform
- 04
Party identification and the funnel of causality
- 05
Partisan dealignment
- 06
Education, generation and gender as new bases
- 07
The personalisation of politics
Worked example · free
Ordering causes in the funnel of causality
- 1Growing up in a union family is an ascribed characteristic at the wide end of the funnel.
- 1The inherited Labor attachment is partisanship, formed early through socialisation.
- 1The impression made by the leader belongs to the election campaign stage, with issues and leaders.
- 1The Labor vote is the outcome at the narrow end, explained by all earlier stages.
Key terms
- Micromega rule
- Colomer’s generalisation that large parties prefer small assemblies, small districts and plurality rules, while small parties prefer the opposite.
- Party identification
- A long-term emotional attachment to a political party, usually formed early in life, that shapes how a voter sees politics.
- Partisan dealignment
- The weakening of voters’ attachments to the major parties, leading to more volatility and minor party support.
- Personalisation
- The growing role of party leaders, rather than parties, as the cue voters use at elections.
- Electoral volatility
- The extent to which voters change their party choice from one election to the next.
Electoral Systems and Electoral Change FAQ
Does proportional representation cause multiparty systems?
Duverger argued that electoral rules shape the number of parties, but Colomer shows that parties also choose the rules, so PR often maintains a multiplicity that already existed. An essay should treat the relationship as running in both directions.
Why is turnout higher under proportional representation?
Cross-national survey research finds turnout tends to be higher under PR, and that greater disproportionality between votes and seats goes with more abstention. One explanation is that PR raises political efficacy, the belief that taking part makes a difference.
Is partisan dealignment happening in Australia?
Yes, though more slowly than in some countries. Non-partisans now make up about one in four voters, and in 2025 dealigned voters outnumbered Liberal partisans for the first time. Compulsory voting and frequent elections have slowed the trend.
What is negative partisanship?
It is a lasting dislike of a party rather than attachment to one. The lecture argues it explains much support for the radical right in Europe and helps account for tactical voting, where people vote mainly to keep a disliked party out.
Why do parties rarely reform electoral systems?
The conventional view is that the winners under existing rules have little reason to change them. Katz shows reform is more common than that implies, because parties misjudge effects, need partners or face public pressure, and Renwick finds referendums can force reforms that elites cannot fully control.
Exam move
Learn the two arrows of causation, Duverger and Colomer, and practise a paragraph that uses both on a real case such as New Zealand’s move to MMP. Keep Renwick’s two paths to reform and Katz’s point about incumbents as ready evidence for questions on why reform happens. For electoral change, draw the funnel of causality from memory and attach one Australian fact to dealignment.
Then prepare a short answer on what is replacing class and religion, naming education, generation and gender, because this connects directly to the cleavages chapter and to the UK case. A good final drill is to write the PR versus plurality essay plan in ten minutes: a thesis, one PR case and one plurality case with a fact each, the turnout evidence, and a closing judgement.
Then write a second plan on whether dealignment threatens democracy, using the Australian figures and the lecture’s list of consequences.
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