Social Choice
Session 22
Carmen Pasca and John Hey
Mattia de Grassi di Pianura
A note about the last session (Thursday)
• On Thursday we will be talking about assessment.
• We will be giving advice about the written examination - and
talking specifically about the specimen paper which you can
find on the site.
• We will also be giving advice about the Group Project.
• The title should be in the form of a question and should be
agreed with the docenti.
• We can give advise about the title and about the structure of
the Project but not about the detail. We want to be fair (we
would not give advice on detail in an examination!)
• (Note: the docenti have two roles in the Italian system –
teachers and examiners.)
Session 22: Overview
• The purpose of this session is to give an
overview of the course as a whole.
• It is a huge course, ranging from economics,
through sociology, politics and philosophy, to
political science.
• You are not expected to know all the detail –
just the general ideas and principles.
• You will be assessed on your understanding of
these generalities.
Implications
• Neither the written examination nor the
Group Project need to be full of remembered
facts.
• We do not expect you to remember lots of
detail – it is not a test of memory.
• We are looking for arguments which use and
illustrate those of the course.
• We want you to demonstrate competence in
understanding general principles.
Session 1
• Introduction and Overview
• Here we talked about the material that we
were going to cover and about our
pedagogical methodology.
• We talked about different media: lectures,
experiments, discussions, debates and films.
• We warned you about not getting bogged
down in detail but instead concentrating on
the main principles.
Session 2
• How Can Societies Choose? (part 1)
• This was the first of two sessions devoted to
Arrow’s famous Impossibility theorem
concerned with the question of aggregating
individual preferences into Society’s.
• His theorem showed the incompatibility of
Universal Domain, Consistency, Pareto and the
Independence of Irrelevant Alternatives.
• Surprising? Important? Implications?
Session 3
• How Can Societies Choose? (part 2)
• We continued with Arrow’s framework
(crucially ordinal non-comparable
preferences) and asked if, by weakening his
axioms, we could make any progress.
• We considered various weakenings
(particularly that of a complete ordering, Sen’s
idea of ‘local’ responsibility, Gibbard’s idea of
inalienable rights) but reached the same
impasse. Surprising?
Session 4
• How Can Societies Choose? (part 3)
• Here we took a different tack.
• Rather than asking if we can aggregate
preferences in some way into Society’s
preferences... (e.g. over distributions)
• ... we asked whether we might be able to
reach agreement on general principles for
choosing (between distributions).
• Similar (and other) difficulties.
Session 5
• An Experiment trying to discover what axioms
people agree with.
• This is a follow-up to the Fleurbaey book.
• We gave subjects a choice between different
axioms and asked them which they preferred.
• Notice that this follows up the methodology
of asking which axioms they prefer for
deciding between distributions, rather than
asking which distributions people prefer.
Session 6
• How Can Societies Choose? (part 4)
• Here we made a stronger assumption about
preferences. Up to now assumed ordinal.
• We explored in this session the possibility and
implications of them being cardinal and
comparable.
• If possible it makes the question of Social
Choice much much easier.
• But does it make sense?
Session 7
• Strategic Decision Making.
• An introduction to Game Theory.
• Useful for studying the outcome for groups/societies
when decision-making is individual.
• We studied simple static games, sequential games,
dynamic (repeated) games, and hinted at evolutionary
games.
• The key concept is that of a Nash Equilibrium in such
games.
• We discussed whether we agree with this concept and
whether it is empirically valid. (Naples/Sweden)
Session 8
• A Public Goods Experiment
• Here we executed an economics experiment in the
classroom...
• ... reproducing the public goods problem with
‘appropriate incentives’.
• We showed that the predictions of the theory were
not exactly correct immediately...
• ... but that we observed convergence towards it.
• We discussed whether we might be able to change
the outcome with different rules.
Session 9
• Public Goods and the Free-Rider problem.
• We began with a definition of a public good – non-rival
and non-excludable.
• We showed with a bit of Game Theory and the concept
of a Nash Equilibrium that everyone would free-ride and
that consequently the public good would not be
provided.
• Is this an argument for state provision?
• And hence the existence of the state?
• With different rules things might be different.
• Do we need a State to impose those rules?
Session 10
• How Do We Get Round the Free-Rider
Problem?
• Collective Action? (The “Big Society” – later)
• The paradigm of collective action (Olson): individuals
have no incentive to act for organisations that
provide public goods because they benefit anyway.
• Theories of collective behaviour
• Collective action today “gives the power to the
people”….
• The return of social questions….
Session 11
•
•
•
•
How Do Societies Choose? (part 1)
This session is definitional.
We have different methods at different levels.
We talked about different decision-making
procedures: monarchies, presidents, parliaments,
regional assemblies, district councils,
committees.
• We looked at the French and British cases and the
different structure of political institutions and
voting systems in the two countries.
Session 12
• How Do Societies Choose? (part 2)
• We broke this down into two levels : how are decision –
making bodies chosen or elected and how do they take
decisions.
• We examined different voting systems for parliaments,
regional and local assemblies in EU and around the
world.
• We discussed different voting systems: majoritarian,
proportional and mixed systems.
• The conclusion of this part: there is no perfect voting
system (see Arrow!).
Session 13
• How Do Societies Choose? (part 3)
• We discussed the voting systems used within
decision-making bodies.
• The case of French bureaucracy.
• The system in France today is a mix of history,
tradition, culture and reformation.
• The interest of this session is the comparison
with your own country.
Session 14
• Social Contract Theory (part 1)
• The birth of Social Contracts and the Social Contract
Theory through the three philosophical traditions:
• The Greek Tradition: Plato, Aristotle.
• The Modern tradition: Hobbes, Locke , Rousseau.
• The Contemporary Tradition: Rawls, Sen, Nozick.
• The various social contract theories : theories of justice
and distributive justice.
• In this part we focussed on idea of mutual agreement
between citizens and State in terms of duties and rights.
Session 15
• Social Contract Theory (part 2)
• We discussed the economic foundations of Social
Contract Theory and we focussed on the Rawlsian
principles of a Just society and the concept of
Distributive Justice.
• Sen’s approach of fairness, in terms of Capabilities
and Functionings related with personal well-being
(utility and resources).
• According to Sen the human well-being is based on
freedom of choice.
Session 16
• Social Contract Theory (part 3)
• We discussed the political concept of Welfare
State in EU and US.
• We analysed the passage from a Welfare State to a
Welfare Society.
• A Welfare State provides a range of goods to its
citizens through legal entitlements.
• The Welfare Society provides welfare through
private means in terms of social services.
• The new welfare today.
Session 17
• The US Constitution.
• The adoption of the US Constitution was one
of the crucial moments in the birth of
American Nation.
• The major feature of this Constituion is its flexibility.
• Why?
• The Constitution embodies the principle of Universal
Suffrage.
• It applies the logic of “common law”.
Session 18
• A comparison of different constitutions,
particularly those of the US, Italy and France.
• The preamble of the US Constitution mark the difference
with the other original Constitutions.
• The major characteristic of the US Constitution is the will
to protect citizens against any abuse of power!
• The Italian Constitution is born on with an historic
compromise and is based on labour.
• The French Constitution has undergone several reforms
up to the 1958 Constitution.
Session 19
• A debate/discussion on David Cameron’s idea
of the “Big Society”.
• Giving Power (back) to the People....
• ... and in doing so, getting people to take
social responsibility...
• ... getting round the free-rider problem.
• What was decided in the debate/discussion?
• A good idea or not?
Session 19
• A debate/discussion on David Cameron’s idea
of the “Big Society”.
• Giving Power (back) to the People....
• ... and in doing so, getting people to take
social responsibility...
• ... getting round the free-rider problem.
• What was decided in the debate/discussion?
• A good idea or not?
Session 20
• Cambridge Union Style debate on the motion
“This House Believes that Italy should adopt
the US Constitution”.
• Result?
Session 21
• The film “Bowling for Columbine”.
• As Mattia explained we showed this film to
emphasise the contentious issues involved
when different groups of society have
different principles and beliefs than others.
• In this kind of instance, can the state invoke
some general principles that are ‘above’ those
of certain citizens?
• Is there an answer?
And finally…
• On Thursday is the final session of the course.
• We will be talking mainly about assessment,
both with a written examination and through
a Group Project.
• If you have not yet started a project we
advise you to take the written examination.
• I am around this week until Friday and can
help (constrained by fairness) with projects.
• Book an appointment with us.