Transcript Document

Social Choice
Lecture 12
Carmen Pasca and John Hey
Voting Systems
• Plan for today: to examine actual voting systems in use in
Europe and to discuss their properties.
• Electoral systems in Europe: We examine the rules and
mechanisms used in democratic elections across the
parliaments of Europe.
• Elections lie at the heart of representative democracy,
enacting citizens' rights to have a say in by whom they are
governed.
• The electoral process is the ultimate symbol and act of
modern democratic societies.
Desirable features of voting systems 1
• All electoral systems seek to take account of at least some or
all of the features on this and the following two slides; which
of these are deemed most important tends to shape people's
preference of electoral system.
• Ensuring a representative parliament: parliaments should
reflect the population that chose it, both in terms of political
support, but also regionally and ethnically.
• Making elections accessible and meaningful: Voters should
feel that their taking part will make a difference to the result,
or else they will increasingly refuse to participate,
undermining the legitimacy of the results.
Desirable features of voting systems 2
• Facilitating efficient and stable government. The system
should make it possible for the government of the day to
enact legislation, run the economy and carry out the other
tasks of government. The system should also be set up in such
a way that it does not favour one party at the expense of the
others.
• Holding the government and representatives accountable for
their actions. This is one of the corner stones of electoral
systems. They must provide a check on the actions of
individuals once elected, and provide an opportunity at
regular intervals to remove those who the electorate feel are
no longer suitable for office.
Desirable features of voting systems 3
• Promoting and respecting a parliamentary opposition. To be
effective, governments also need to have an opposition to
assess proposals critically, speak up for the interests of those
not represented by the government, and provide reassurance
to the electorate that there is always the possibility of
changing governments at a later date.
• On the next few slides we discuss the different types of voting
systems that exist in practice.
Majoritarian systems
• Majoritarian, or plurality, systems represent the oldest and
simplest electoral system category, based on the principle
that whichever candidate receives the most votes in a
constituency is deemed elected.
• The following three slides discuss three varieties of majority
systems which operate on the basis of single-member
constituencies.
'First-past-the-post' (FPTP) or simple majority
• This is the most straightforward electoral system, and is
found in the UK, USA, Canada and India.
• To win, a candidate need only receive one more vote than
any other candidate. Since a minimum threshold (i.e. a
minimum level - usually a percentage - of the popular vote
required for a party to be allowed to gain parliamentary
representation) is rarely a part of this system and an absolute
majority is not required, the winner may still win with a
relatively small proportion of the vote.
Second Ballot Majority Runoff or absolute majority
• This system requires a candidate to obtain one more vote
than half the votes cast in order to be elected. If no candidate
gets that many votes, a second round is held.
• In this system, either a simple majority is sufficient in the
second round, or a "run-off" election is held between the two
candidates who received the most votes in the first round,
also along absolute majority lines. France and the Ukraine
both use variations of this system.
Alternative Vote
• This system also seeks to ensure that a candidate is elected by an
absolute majority, but does so in a single round using Preferential
Voting (i.e. expressing a rank order of preferences) instead of a
two-stage system. Constituents vote for a single candidate but
indicate, in declining order, their preferences for other candidates.
If none of the candidate gets an absolute majority on the first
count, the candidate who polled the fewest votes is eliminated, and
his preferences are distributed among the remaining candidates.
This is repeated until one of the candidates has an absolute
majority. This is used in Australia and for the Irish presidential
elections.
• In the UK there will be a referendum in May to decide whether this
system will be introduced there.
Properties of Majoritarian systems 1
• Majoritarian systems are simple. They do not require complex
mathematics to produce their results and they encourage
transparency, since votes are easily translated into
parliamentary seats. Many proportional systems, such as
Single Transferable Vote, are unattractive in that they involve
very lengthy and complex calculations.
• The 'winner-takes-all' philosophy behind these systems
focuses on producing a clear, strong and stable body of
representatives and government, not on mirroring the makeup of the general population.
Properties of Majoritarian systems 2
• Because of the way that majoritarian systems disproportionately
reward large parties over small parties, the leading party is rarely
required to build a coalition to create a government.
• A one-party government (which, one should remember, is already a
complex coalition of interests) is therefore free of the problems
that can emerge from being involved in a coalition which might
make it weak: government is immediately broadly united; policy
need not be diluted as it might in a coalition where a partner party
may demand policy concessions; ministerial portfolios can be
distributed without fear of party political battles or major policy
cleavages (although other battles will still rage); the identity and
message of a party in government need not be confused, or
aggravated, by its close association with another party.
Properties of Majoritarian systems 3
• Just as a majoritarian system tends to create strong
government, it also tends to lead to a strong alternative party,
such as in the UK and the USA.
• This creates a dynamic political arena where government needs
to work hard because there is always a viable and strong
alternative which the public can chose to replace them with
• Smaller parties are not effectively represented in majoritarian
systems can be seen to have some advantages. They encourage
minority groups to integrate into the larger parties, which is
desirable both for the minority group (which can gain the
political support for some or all of its concerns) and the large
group (which gains the electoral support of the minority).
Properties of Majoritarian systems 4
• Different groups are brought together by political need which
encourages cooperation and the creation of parties with 'broad
church' appeal, rather than division by electoral systems which
may only serve to highlight differences and keep minorities at a
distance. It can also serve to discourage extremist minority
parties from gaining parliamentary representation,
• Individual citizens feel that they are part of the democratic
process through a single representative, who is there to help
with individual or community casework. The election of
representatives by a proportional system in a multi-member
constituency (which may even be the entire country) would not
determine this link.
Properties of Majoritarian systems 5
• Single-member constituencies which operate in majoritarian
systems also encourage the linkage of an elected
representative to a particular geographic area and the
residents of that area, who become his or her constituents.
This link encourages those elected to prioritise serving their
constituents above satisfying the party hierarchy, since their
re-election will depend entirely on those same people.
• This link is particularly important in the UK, where MPs have
always been viewed as representatives of a specific area, not
of the UK as a whole.
Proportional Systems 1
• While majoritarian systems provide the oldest model for
electoral systems, proportional representation (PR) systems
are currently the most widely used in Europe. Its focus is on
the creation of a parliamentary chamber which accurately
reflects the diverse make-up of an electorate. The two main
PR system categories are Party List and Single Transferable
Vote. Both of these carry a range of considerations in creating
representative parliaments.
Proportional Systems 2
• The size of the constituency (also refered to as 'district
magnitude') is important since it can affect how 'accurate' the
results reflect a general electorate. 'Full PR' considers the
whole country as a single constituency, with seats allocated
on a pro rata basis according to the number of votes cast. This
is considered to yield the most 'pure' form of PR. 'Limited PR'
sees elections taking place in several constituencies, and is
considered to not produce as accurate a snapshot of the
population, since the greater the number of constituencies
(and hence the fewer the number of seats available per
constituency), the harder it is to ensure complete
proportionality.
Proportional Systems 3
• Many systems used include a threshold.
• This aims to reduce the extent to which proportionality is
taken. By putting in place a minimum level of national support
required for a political party to be allowed to gain
parliamentary representation, it limits the ability for very
small parties to gain representation. It is understood that the
electoral threshold had its origin in inter-war Germany, as a
result of the Weimar Republic's concern with extremist
groups. Some thresholds are nominal, others are so large that
it challenges the basic idea behind using a PR system.
Proportional Systems 4
• In some countries, political parties not reaching the
thresholds and getting no seats can potentially waste millions
of votes. Another requirement which some countries (many
in central and eastern Europe) also have in place is a
minimum quorum level, which demands that for an election
to be deemed valid and fully representative the turnout must
meet or exceed a percentage of the electorate.
Party List system 1
• A Party List system presents multi-member constituency
electorates with political parties putting forward slates or lists
of candidates.
• It represents the principal PR system in operation, although
there are many variations of it, based on constituency size (as
covered above), thresholds and quorums (also examined
above), rules about whether the electorate can have
preferences for individuals on party lists, whether the
Greatest Remainder or Highest Average systems are used and
which formulas are used within them.
Party List system 2
•
Before looking at the Greatest Remainder and Highest Average systems, one must
cover perhaps the most important variant in the Party List system: the ability of
the voter to influence the party list. The ability of the voter to influence the party
lists acknowledges that voters will often have preferences for individual
candidates within party lists and that they might also wish to satisfy those
preferences regardless of what the party hierarchies have put in front of them.
The extent to which a voter can have choice in a Party List PR system is
determined by one of the following variations. Preferential Voting allows voters to
decide their own order of preference, different from that indicated by the party.
The voters may only, however, vote for one list. Vote-Splitting allows voters to
select candidates from competing lists, and thus draw up their own list. The
commonest used variation is the Closed List system, where the electorate are
simply allowed to vote for one party list, not an individual. It is up to the party to
decide who should get the chance to fill the seats given to them (usually
determined well in advance with the candidates placed in order of priority).
Preferential Voting
• Preferential Voting allows voters to decide their own order of
preference, different from that indicated by the party.
• The voters may only, however, vote for one list. Vote-Splitting
allows voters to select candidates from competing lists, and
thus draw up their own list.
• The commonest used variation is the Closed List system,
where the electorate are simply allowed to vote for one party
list, not an individual. It is up to the party to decide who
should get the chance to fill the seats given to them (usually
determined well in advance with the candidates placed in
order of priority).
Proportional Representation
• The experience of PR has been that it has increased the
number of women in parliaments. Some political parties have
taken affirmative action and drawn up official targets for the
proportion of women and those from ethnic minorities on
their party lists. Defenders of such targets argue that
although artificial, its aim is to temporarily speed-up change
to the status quo, which can often only be done by such
targets in closed PR systems.
• PR tends not to result in one party having an absolute
majority of the votes, thus making coalition government the
norm. This leads, in theory at least, to a more consensual and
inclusive style of government.
Mixed Systems 1
• There are a range of systems which try to strike a balance
between majoritarian and proportional representation
systems, and are generally (if rather untidily) categorised as
Mixed Systems.
• These can broadly be divided into those which try to bring
together elements of majoritarian and proportional systems
to try and come up with a seat-distributing mechanism
incorporating the best of both world (but end up tending to
lean more towards one system or the other), and systems
where both majoritarian and proportional mechanisms are
used in different stages.
Mixed Systems 2
• Cumulative or Block Vote.
• Voters have a number of votes equal to the number of seats
available and are free to distribute them as they please
among all the candidates, even to the extent that one
candidate can receive all the votes of one voter, or
conversely, where the voter can give each candidate one
vote. Seats are distributed among candidates polling the most
votes. A variation of this is Party Block Vote, where voters are
only allowed to vote once for one entire party list, which
results in the entire list of candidates of the winning party list
taking all the seats in a multi-member constituency.
Mixed Systems 3
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•
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Limited Voting. Used in multi-member constituencies, voters may vote for several
candidates on the ballot paper, but always fewer than the number of seats to be
filled. Candidates polling the most votes are elected. It was used in some UK
constituencies in the late 19th century.
Single Non-Transferable Vote. Under this system, there are several seats to be
allocated in each constituency. However, each voter may only vote for a single
candidate, with those candidates who gain the most votes being elected.
These systems, however, use separate majoritarian and proportional mechanisms
for different constituencies
Additional Member (or Parallel) system. A proportion of seats are distributed using
a majoritarian method, while the remaining seats are allocated using a PR system,
usually on a regional or nationwide basis. The Russian Duma, for example, has
seats elected by a majority vote in single-member constituencies, as well as by PR
nationally. Japan is also a user of this system.
Mixed Systems 4
• Mixed Member Proportional system (MMP). This system works very
similarly to Additional Member, in that it incorporates majority
voting for one portion of the seats and Party List PR for the other.
However, "under MMP the list PR seats compensate for any
disproportionality produces by the [ majoritarian system-elected]
district seat results. For example, if one party wins 10% of the
national votes but no district seats, then they would be awarded
enough seats from the PR lists to bring their representation up to
approximately 10% of the parliament". This 'compensating'
mechanism system is used in Germany, Hungary and New Zealand,
and is seen as particularly benefitial in its ability to keep local
constituency representation while also awarding smaller parties
their fair share of the popular vote.
Systems for National Elections
in EU states 1
• The systems used for parliamentary elections in the member
states of the European Union present a varied picture, each
products of different political circumstances and traditions.
Bicameral, unicameral, majoritarian, proportional, and mixed
systems are all well represented in the EU, displaying a
diversity which is often augmented by certain aspects of the
electoral law not concerning the vote-distribution
mechanisms.
• Compulsory voting rules in Belgium and Greece, for example,
sit alongside the less demanding requirements of other
Member States.
Systems for National Elections
in EU states 2
• In the bicameral systems, the Lower House is the most
important, the result there determining the make-up of the
government. A wide range of systems are in use for
parliamentary elections, although proportional systems
dominate. The UK uses the FPTP system in single-member
constituencies. France also has single-member
constituencies, but uses the two-stage Second Ballot
Majority Runoff system, where an absolute majority is
required to gain a seat. Spain, and Italy use the Additional
Member system, while Germany uses the Mixed Member
Proportional system. Finland's system is principally PR, but
the representative for Finland is chosen by simple majority.
Systems for National Elections
in EU states 3
• Most of the Upper Houses are chosen by appointment or
indirect election, while three - Belgium, Spain and Italy - have
directly elected elements.
• Belgium uses the same proportionality-based voting system
as for the Lower House, but the representatives are chosen
along the lines of the regions and language communities.
• Italy uses a mixed system for the Upper House, most seats
being filled by simple majority voting, the rest by
proportionality.
• Spain's Upper House has most places filled by simple majority
voting, but about a sixth of seats are indirectly chosen by
regional assemblies.
Systems for National Elections
in EU states 4
• The indirectly appointed upper chambers have a variety of different
methods for choosing members.
• In four of the countries - Germany, Austria, Holland and Spain - the Upper
House is made up of members of regional or local assemblies. In France,
the Senate is made up of people chosen by local electoral colleges.
• In Ireland, appointments to the Upper House are made in part by the
Prime Minister and by indirect elections by some universities, county
councils, panels representing different interests in society or the outgoing
House. In the United Kingdom, there are four groups of members:
hereditary peers (aristocracy), life peers, Law lords, and certain bishops.
The government recently started a two-stage reform of the House of
Lords, removing the right to sit for all but 92 hereditary peers in an
"interim" house. Stage two will produce a final dispensation, following the
publication of the report from a Royal Commission to consider the
composition, roles and functions of the second chamber.
Summary of voting systems 1
• Absolute Majority: More than half the total number of votes
cast. For the Absolute Majority system, see Second Ballot
Majority Runoff.
• Additional Member (or Parallel) system: Mixed electoral
system where a proportion of seats are distributed using a
majoritarian system, and where others are distributed on a
proportional basis.
• Alternative Vote system: Preferential absolute majority
system, usually used in single-member constituencies, where
voters number candidates in order of preference. If there is
no outright winner, the least favoured candidate is eliminated
and his second preferences are redistributed. This continues
until someone gets over 50% of the vote.
Summary of voting systems 2
• Closed List: A list of candidates (in rank order of priority to be
given seats) drawn-up for elections taking place by a form of
Party List, which may not be adjusted by the voter.
• Constituency: A geographical area into which a country is
divided for elections. Can be a 'single-member constituency'
where only one parliamentary seat is being contested, or a
'multi-member constituency' where more than one seat is
being contested.
Summary of voting systems 3
• Cumulative (or Block) Vote: A majoritarian system for use in
multi-member constituencies where voters have a number of
votes equal to the number of candidates standing and are
free to distribute them as they please. Seats are filled
according to who receives the most votes.
• D'Hondt Quota: The most common divisor used in the
Highest Average Party PR system, it operates the following
dividers: 1, 2 , 3, 4, etc.
• Droop Quota: Used for allocating seats in both the Greatest
Remainder Party List and the Single Tranferable Vote systems,
it
Summary of voting systems 4
• Elimination: In Alternative Vote and STV systems, it occurs
when candidates have too few votes to remain in a contest.
• 'First-Past-The-Post' (FTPT)(or Simple majority) system:
Candidate with the largest number of votes wins, regardless
of whether he or she has an absolute majority.
• Greatest (or Largest) Remainder system: A Party List PR
system which uses a type of formula (e.g. Hare, Imperiali, etc)
to devise a quota of the votes necessary for a party to secure
a seat. Once all seats have been distributed according to the
quota, remaining votes which do not reach the quota are
counted to distribute any remaining seats to those with the
most votes left-over.
Summary of voting systems 5
• Hare (or Simple) Quota: A variety of the Greatest Remainder Party
List PR system, it is a quota calculated as 'votes divided by seats'.
• Highest Average system: A Party List PR system which distributes
seats according to parties which have the highest averages after
being divided by a particular formula (e.g. d'Hondt, Sainte-Lague
system, etc).
• Imperiali Quota: The quota under this system is reached by
dividing the total number of votes cast by the number of seats to
be filled, increased by two.
• Limited Vote: Used in multi-member constituencies, voters may
vote for several candidates on the ballot paper, but always fewer
than the number of seats to be filled. Candidates polling the most
votes are elected.
Summary of voting systems 6
• Majoritarian systems: Generic term for systems where seat(s) are
distributed according to whichever candidate(s) get the most
individual votes.
• Mixed Member Proportional system (MMP): This system works
very similarly to Additional Member, in that it incorporates majority
voting for one portion of the seats and Party List PR for the other.
However, it differs in its ability to award seats through PR to overcompensate for parties which attracted a good share of the popular
vote in the majoritarian elections, but failed to make any gains.
• Mixed systems: Generic term for single electoral systems which are
either composed of elements of both majoritarian and proportional
systems or those which include separate majoritarian/proportional
procedures, such as the Additional Member system.
• Parallel system: See Additional Member system.
Summary of voting systems 7
• Party Block Vote: Voters are only allowed to vote once for
one entire party list, resulting in the entire list of candidates
of the winning party list taking all the seats in a multi-member
constituency.
• Party List system: The principal PR system, operated by either
Greatest Remainder or Highest Average formula, it is an
election in a multi-member constituency where all candidates
are placed on political party 'lists'. Depending on the variety,
an electorate may only be able to vote according to Closed
List rules, may be able to partake in Preferential Voting, or
could even pick and choose candidates from across the lists,
as allowed by Vote-Splitting.
Summary of voting systems 8
• Preferential Voting: Party List PR rule variant which enables
voters, once they have voted for one party list, to choose
their prefered ranking of candidates.
• Proportional Representation (PR): Generic term for systems
which seek to ensure that the results of elections are as
proportional as possible to the make-up of an electorate.
Party List systems and STV are varieties of PR.
Summary of voting systems 9
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Quorum: a minimum level - usually a percentage - of the full electorate required
to vote to validate the results of an election. (i.e. If only 29% of an electorate
voted in an election requiring a 35% quorum, the results would be deemed invalid
due to the low level of voter participation).
Single Non-Transferable Vote: A mixed system for use in multi-member
constituencies, where voters only have one vote. Those who receive the most
votes win.
Single Transferable Vote (STV): Main alternative PR system to Party List, a
candidate is elected as soon as he reaches the a quota calculated by the Droop
quota. Additional votes are redistributed to other candidates on the basis of
second choices. The same operation is carried out in the case of the candidate
who polled fewest votes, who is eliminated. If there are still seats to be filled after
the second count, the process continues.
Threshold: A minimum condition for securing representation. This divide limits
purely proportional results by distributing seats only to parties with …
Vote-Splitting: This allows voters to select candidates from competing lists in a
Party List PR system, and thus draw up their own list of candidates.
Conclusions
• There is no perfect voting system (but we
knew that from Arrow!).
• There is a big literature pointing out the
pros and cons of the various systems.
• Different countries have different systems.
• Why?
• Partly historical and partly cultural.