electoral system
Electoral systems
electoral system types
majoritarian
single-member constituencies
single-member plurality (SMD) / ‘first-past-the-post’
two-round system (TRS)
alternative vote (AV)
majoritarian SMD rules
1 MP elected in each constituency
each party presents 1 candidate in each constituency
citizens vote (X) for 1 of the candidates
candidate with the most votes in a constituency wins a seat
examples: Botswana, Canada, India, Jamaica, UK, USA, Zambia
majoritarian TRS rules
1 MP elected in each constituency
each party presents 1 candidate in each constituency
citizens vote (X) for 1 of the candidates
if no-one wins 50% (usually), the top 2 go through to a ‘run-off’
candidate with the most votes in a constituency wins a seat
examples: Belarus, Congo, France, Togo (and many presidential elections)
majoritarian AV rules
1 MP elected in each constituency
each party presents 1 candidate in each constituency
citizens rank the candidates (1, 2, 3, 4, 5, etc)
if no one wins >50% (usually) of first preference votes, the candidates with the fewest votes is eliminated and their 2nd preferences are re-allocated to the remaining candidates, and so on, until someone wins >50%
examples: Australia, Fiji, Papua New Guinea
proportional
multi-member constituencies
closed-list PR (CLPR)
open-list PR (OLPR)
single-transferable-vote (STV)
a proportional - or ‘proportional representation’ (PR) - electoral system uses multi-member constituencies
the rationale behind PR systems is to produce a proportional translation of votes into seats: parties should win proportionally as many seats as they win votes
PR systems can be divided into systems where:
citizens vote for parties (closed-list PR)
citizens vote for individual candidates (open-list PR, single-transferable-vote)
proportional CLPR rules
several MPs elected in each constituency (’multi-member’)
each party presents a list of candidates in each constituency
citizens vote (X) for one of the party lists in the constituency
seats are allocated to parties in each constituency in proportion to the votes they received in that constituency
most countries have local or regional multi-member constituencies, while a few have only one single national constituency (e.g. Israel)
examples: Argentina, Austria, Israel, Nicaragua, Poland, Spain, South Africa, Turkey
proportional OLPR rules
several MPs elected in each constituency (’multi-member’)
each party presents a list of candidates in each constituency
citizens vote (X) either for a party (a ‘party vote’) or for an individual candidate (a ‘personal vote’)
seats are allocated to parties in proportion to the total votes they receive in a constituency (party votes + personal votes)
seats are allocated to candidates within parties according to the number of personal votes each candidate receives
examples: Belgium, Denmark, Brazil, Chile, Czech Republic, Estonia, Finland, Sweden, Switzerland
proportional STV rules
same as alternative vote, but in a multi-member constituency
several MPs elected in each constituency (’multi-member’)
each party presents several candidates in each constituency
citizens rank the candidates (1, 2, 3, 4, 5, etc)
if any candidate reaches a ‘quota’ of votes, s/he is elected
if not enough candidates reach the quota the bottom candidate is eliminated and his/her 2nd preferences are allocated to the remaining candidates, and so on, until all the seats have been allocated
examples: Ireland, Malta, Scottish Local Councils
mixed
single-member & multi-member constituencies
mixed-member proportional (MMP)
mixed-member majoritarian (MMM)
rules
the electoral system has 2 tiers:
some MPs are elected in single-member constituencies
some MPs are elected in a multi-member constituencies
each party presents 1 candidate in a single-member constituency and a list of candidates in a multi-member (regional or national) constituency
citizens (usually) have 2 votes: 1. for a candidate in a single-member constituency; and 2. for a party on a regional/national party list
in each single-member constituency the candidate with the most votes is elected and…
in a mixed member proportional systems: the party-list seats are allocated to compensate those parties who have not won enough single-member seats given their overall vote-share → examples: Bolivia, Germany, Mexico, New Zealand, Scottish Parliament
in mixed member majoritarian systems: the party-list seats are allocated separately, in proportion to the votes received by parties in the multi-member party list constituencies → examples: Japan, Lesotho, Thailand
constituency seats
299 single-member constituencies
list seats
410 seats allocated in 16 regional (Länder) constituencies, to top-up/compensate parties for not winning enough SMD seats given their vote-share
trade-offs in electoral systems
Duverger’s law
french political scientist Maurice Duverger (1954) made the following proposition
majoritarian systems → two-party systems
proportional systems → multi-party systems
he suggested 2 reasons for this:
mechanical: majoritarian systems → big parties win proportionally more seats than their vote-shares, while small parties win proportionally less seats than their vote-shares
psychologically: majoritarian systems → people vote strategically for bigger parties if their most preferred party has no chance of winning in a constituency
Cox’s correction of Duverger
Gary Cox (1997) pointed out that Duverger’s logic only works at the constituency level
if voters are strategic, then they should ‘coordinate’ around only those candidates/parties that have a realistic chance of being elected
Cox predicts that in each constituency the number of competitive candidates should equal the number of seats to be elected plus one. for example
1 (single-member) ⇒ 2 competitive candidates
6 (multi-member) ⇒ 7 competitive candidates
Cox’s correction
a single-member system will only produce 2 parties, if the same 2 parties are the top parties in every constituency
in geographically heterogeneous societies (e.g. Canada, UK, India), a single-member system will produce a multi-party system
representative parliaments vs. accountable governments
proportional systems
maximise representation
vote-shares map ‘fairly; onto seat-shares
parliament is a ‘microcosm’ of society
but, governments (and usually coalitions) form after elections
low ‘clarity of responsibility’
majoritarian systems
maximise government accountability
small vote shifts → big seat shifts (more ‘responsive’)
limits number of parties → single-party government more likely (’high clarity’)
but, (often) produce highly disproportional outcomes
cohesive parties vs. accountable politicians
closed-list PR → voters can’t remove unpopular politicians from parliament as long as they rank high on the party list and their party gets enough votes, they would need to vote for another party: parties can “force” politicians into parliament
SMD → non-career politicians have more chances under SMD systems, while closed-list PR favours career politicians (”moving up the ranks”)
open-list PR → voters can remove unpopular politicians from parliament by supporting other candidates from the same party: more accountability, incentive for MPs to listen to their constituents
open-list PR → creates more “mavericks” that vote against the party line (and their own government): less cohesion but more accountability
PR can be “modified” to limit the number of parties in a parliament, and/or to give extra seats to the biggest parties
small multi-member districts (low district magnitude) → more seats for big parties, less seats for small parties - e.g. Finland, Spain, Portugal, Czech Republic
high electoral threshold (e.g. 5% of votes minimum to win a seat) e.g. Germany (5), Sweden (4), New Zealand (5), Austria (4)
mixed-member majoritarian - e.g. Japan, Thailand, South Korea, Taiwan, Hungary
by reducing the number of parties elected and/or giving extra seats to the biggest parties, these mechanisms make government formation easier, and encourage voters to support larger parties
district magnitude
the number of members elected in a district: the average size of the constituencies can constitute an effective threshold
a low average district magnitude can produce two-party systems
reason: small parties do not get seats in small constituencies with few seats → small districts can work like hidden thresholds
effect → whenever the district magnitude is small, the outcome is likely to be disproportionate regardless of the particular formula used to translate votes into seats
electoral system outcomes
voter turnout
electoral systems, efficacy and turnout
efficacy is a concept in a political science that captures whether voters perceive their votes to make a difference or to count at all
internal → perception of understanding politics and whether one can participate (”politics is too complicated”, “interest in politics”)
external → perception that government and politics are responsive to individual views (”my vote counts”, “voting makes no difference”)
citizen protest and contact
summary
there are 3 families of electoral systems: proportional representation (PR), majoritarian, and mixed systems
there are 2 trade-offs in the choice of electoral systems:
fair representation (PR) vs. decisive election results (majoritarian)
votes for parties (closed-list PR) vs. votes for politicians (open-list PR)
electoral systems have an impact on
how representative parliaments are
how many parties there are in government
how politicians and parties behave
citizens’ political behaviout (voting, contacting & protesting)
… and ultimately what governments do