Speaker: Eva S. Hendriks
Title: The Generalized Condorcet Jury Theorem: Formalizing Democracy
Date and time: Friday 10 September 2010, 16:00
Location: Room A1.04, Science Park 904, Amsterdam

Abstract

Condorcet’s Jury Theorem (Condorcet 1785, hereafter: CJT) estimates the accuracy of outcomes of juries. Juries can be seen as committees voting on binary choices. In this paper a Generalized Condorcet’s Jury Theorem (GCJT) is introduced, discussing committees voting on any type of decision, be it binary, discrete, continuous or otherwise. In a framework where an optimal decision exists, but is unknown at the time of voting, committee members base their voting on the signals they receive. In this paper it is shown that it is optimal for voters to reveal their true signals, and that they will take a decision that is equal to the UMVU estimator of the optimal decision, regardless of the distribution of the signals.

With the formalization of the CJT into the GCJT, the fact emerges that, in the literature, information is not always used efficiently. The GCJT, by using all available information efficiently, reverses some results in the literature, for example it is shown how indirect democracy does not create a loss of accuracy of the decision, contrary to beliefs based on Boland (1989).

The value of this GCJT in legal policy lies in the formalization of democratic processes it enables. It creates the possibility to extend the common CJT analyses to other cases. The applications of the GCJT within the democratic framework are endless. This paper only discuses a few of them, amongst others that the GCJT can be used to determine the accuracy of democratic decisions based on the number of participants in the democratic decision process. It provides a way to quantify the value of democratic processes in their accuracy, and with that enables cost/benefit analyses with respect to committee sizes. The GCJT also discloses the foundations of the expressive function of law.

This is joint work with Giuseppe Dari-Mattiacci and Maarten Havinga.

For more information, see http://www.illc.uva.nl/~ulle/seminar/ or contact Ulle Endriss (ulle.endrissuva.nl).

6-17 December 2010, Logic Summer School, Canberra, Australia

As computers become more powerful, their ability to perform complicated reasoning tasks increases. In order to harness their power, we need to understand the reasoning they can do, and how they may do it more efficiently. This understanding begins with logic.

The Logic Summer School comprises a blend of practical and theoretical short courses on aspects of pure and applied logic taught by international and national experts. The school provides a unique learning experience for all participants, backed up with state-of-the-art computational science facilities at the Australian National University.

For more information, see http://lss.cecs.anu.edu.au/.

Logic and Games Seminar
Friday, September 3, 2010  4:15 pm   Room 4419, GC
Dr. Willemien Kets   (Santa Fe Institute (visiting scholar Stern NYU))
Finite belief hierarchies in games

Abstract. The decision-theoretic approach to game theory requires players to have beliefs about all relevant uncertainty, including
beliefs about other players’ beliefs, and so on, which naturally leads to infinite hierarchies of beliefs. However, players may not be able
to “reason all the way.” This paper constructs finite belief hierarchies by assuming that players’ language is too coarse to reason
about higher-order events. This gives a class of type structures which form a generalization of the standard Harsanyi structures.

Date and time: Monday, 23 August,  16:00-17:30

Location: Room 353, Xinzhai Building

Speaker: Prof. Sven Ove Hansson (Department of Philosophy and the History of Technology, Royal Institute of Technology, Sweden.)

Title: Cognitive realism in belief revision: Representing a finite mind

Abstract:  Since a human mind cannot deal directly with infinite structures, cognitively realistic models of belief change should operate on belief states that have a finite representation. The standard AGM model cannot easily be reconciled with that requirement. Different ways to achieve a finite representation are discussed, in particular: finite language, belief bases, and specified meet contraction. Formal results that compare and connect the different approaches are presented.

Call for Participation: Formal Ethics Week, September 7-10, 2010,
University of Groningen.

The application of formal tools from logic and rational choice theory to
the analysis of ethical concepts and theories is a rapidly growing field
of research. It has proved its mettle by shedding new light on a variety
of concepts that are central to ethical theory, such as freedom,
responsibility, values, norms, and conventions.

The Formal Ethics Week will be held at the University of Groningen (the
Netherlands) on September 7-10,  2010. A joint venture of the Faculty of
Philosophy of the University of Groningen and the Department of
Philosophy of Uppsala University, the workshop aims to bring together
researchers at the crossroads of ethical theory and formal methods.

The event will feature four tutorials by leading scholars:

Tutorial 1: Formal Methods and Philosophy of Public Policy, Luc Bovens
(London School of Economics)

Tutorial 2: Changes in Preferences, Sven Ove Hansson (Royal Institute of
Technology, Stockholm)

Tutorial 3: Evolutionary game theory, the replicator dynamics and the
social network approach, Jason M. Alexander (London School of Economics)

Tutorial 4: The Ethical Bases of Normative Economics, Prasanta K.
Pattanaik (UC Riverside)

Apart from the tutorials, there will be eight working sessions, where
researchers from Groningen and from Uppsala will present and discuss
each other’s work.

Attendance to the Formal Ethics Week is open to everyone, but
registration is required. For more information, and to register, please
visit the website of the workshop:

                    http://www.philos.rug.nl/FEW

Simon Huttegger (UC Irvine) and Kevin Zollman (CMU) “Game Theory, Evolution and Communication

Programme

Tuesday, 13 July (Venue: T206, Lakatos Building)

13.30 – 15.00 Part I. Game Theory and Animal Interaction

Game theory originated to study strategic situations – those situations where how well one individual does depends not only on her own actions but also on the actions of others. These situations occur both in human interaction and in other animals as well. This course will focus on the use of game theory in studying non-human animal interactions. Problems addressed with these tools include: altruism, conflict, and signaling. In studying these types of problem two main techniques have emerged called static and dynamic techniques respectively. This course will introduce students to both of these techniques and discuss the philosophical underpinnings of both.

16.00 – 17.30 Part II. Conventions

In his seminal book “Conventions”, David Lewis analyzed the strategic aspects of communication by using game theory. Since then, the development of a rich set of tools has allowed researchers in economics, theoretical biology and philosophy to considerably expand on Lewis’ basic insights. In this lecture, I will survey some of the most important findings and explain their significance.

Wednesday, 14 July

Workshop on ‘Networks, Signalling, Social Epistemology’. .

(Venue: T206, Lakatos Building, LSE)

10:00 – 10:30  Welcome

10:30 – 11:45  Sanjeev Goyal (Christ’s College, Cambridge), “Strategic Network Formation”

12:00 – 13:15  Rory Smead (LSE) and Jason Alexander (LSE), “Evolution of  Learning on Networks.”

13:15 – 14:30  Lunch

14:30 – 15:45  Simon Huttegger (UC Irvine), “Learning to Transfer Information”

15:45 – 16:15  Tea and Coffee

16:15 – 17:30  Kevin Zollman (CMU), “The inconsistency thesis: when individual  and social epistemology diverge”

Master class readings

- John Maynard Smith, Evolution and the theory of games, Chapters 1 and 2.
- David Lewis, Convention, Chapter 4.
- Brian Skyrms, Evolution of the Social Contract, Chapter 5.

Registration

Please register by sending an email to c.heilmann @ lse.ac.uk.

Further Information

The master classes are organized by the LSE Choice Group and sponsored by the AHRC. The LSE Choice Group| is a group of people based for the most part at the LSE with a shared interest in the theory of rational decision making in individuals and groups and its application to economic, political and social questions. We hold regular seminars on Wednesday afternoons from 17-30 to 19-00 in T206 (2nd floor, Lakatos Building, Portugal Street. Please email c.heilmann @ lse.ac.uk if you are interested in regular updates on seminars and events

Tuesday, 6 July, 5.30-7pm
T206 (Second Floor, Lakatos Building)
 
Luc Bovens (LSE) and Laura Smead (LSE)
Measuring Fairness and Equal Burden Sharing in EU Asylum Policies
 
Abstract.  In the light of attempts to develop a common European asylum policy, we examine what outcome data we would expect from asylum policies that are (i) fair and even-handed and (ii) share burdens equitably between member states.  We formulate various (often conflicting) normative ideals on asylum flows in a federation of states and construct measures to assess how close actual practice is.  In particular, we are interested in whether EU asylum flows have been moving towards or away from these normative ideals over the last ten years.  This involves the application of various data analysis techniques to UNHCR outcome data.  Much of our presentation will be taken up by conceptual and methodological issues of measurement.  For example, the construction of a measure of fairness on the basis of outcome data raises preliminary questions about measuring the variability in sets of proportions;  for the measurement of equal burden sharing we appeal to Lorenz curve and the Gini coefficient –  commonly used tools for income inequality – and this raises questions about the applicability of  inequality measures to the measurement of burden sharing.  We will conclude by presenting the results of our analysis for the period 1999-2008.

Student Session of the Sino-European Winter School in Logic, Language and Computation
http://www.math.helsinki.fi/logic/sellc-2010/stus.html
December 3-18, 2010 Guangzhou, China

The Sino-European Winter School in Logic, Language and Computation (SELLC-2010) will be held in Guangzhou, China on December 3-18, 2010. It is organized for logic students in the spirit of the well-known summer schools ESSLLI in Europe. Details of SELLC-2010 can be found at: www.math.helsinki.fi/logic/sellc-2010/

As a special part of SELLC-2010, the Student Session invites submissions of extended abstracts describing original, unpublished research conducted in the areas of

- Logic
- Language
- Computation

One author of each accepted paper will be invited to give an approximately 20-minute presentation of the paper at the Student Session.

Aim of the Student Session of SELLC-2010:
The aim of the Student Session is to provide an opportunity for students at all levels (Bachelor-, Master-, and PhD-students) to present and discuss their work in progress in the areas of logic, language and computation with a possibility to get feedback from senior researchers. For more information about the Student Session of SELLC-2010, please visit: www.math.helsinki.fi/logic/sellc-2010/stus.html

Submission:
Authors are invited to submit an extended abstract with a maximum length of 5 pages on any topic in the areas of logic, language and computation.

Language of papers: English

Accepted formats: PDF and PS (Latex-generated papers are preferred)

Submissions should be sent to the email address (fan.yang@helsinki.fi) of the organizer Fan Yang.

 
Acceptance:
Each submitted paper will be reviewed by three Student Session programme committee members in the relevant field. Final decision regarding acceptance/revision/rejection will be based on the reviews.

 
Important Dates:
Deadline for submissions: September 20, 2010
Notification of acceptance: November 1, 2010

Organizer:
Fan Yang (University of Helsinki, Finland)

 
Programme Committee:
Samson Abramsky (University of Oxford, UK)
Robin Cooper (Gothenburg University, Sweden)
Juliette Kennedy (University of Helsinki, Finland)
Phokion Kolaitis (University of California, Santa Cruz and IBM Research-Almaden, USA
Jeff Paris (University of Manchester, UK)
Greg Restall (University of Melbourne, Australia)
Mehrnoosh Sadrzadeh (University of Oxford, UK)
Mark Steedman (University of Edinburgh, UK)
Jouko Väänänen (University of Helsinki, Finland and University of Amsterdam, The Netherlands)
Dag Westerståhl (Gothenburg University, Sweden)

 
Sponsors:
Sun Yat-sen University
Institute of Logic and Cognition

Date and time: Wednesday, 23 June, 5.30-7pm
Location: T206 (Lakatos Building, Second Floor)
Speaker: Brian Hill (HEC Paris) 
Title: Beyond Probabilities: Belief, Confidence and Decision-Making
 
Abstract:  The standard representation of beliefs in decision theory and much of formal epistemology, by probability measures, is incapable of representing an agent’s confidence in his beliefs. However, as shall be argued in this talk, the agent’s confidence in his beliefs plays, and should play, an central role in many of the most difficult decisions which we find ourselves faced with – and indeed, in several sorts of decisions which have been largely ignored in the Bayesian literature. The aim of this talk is to formulate a representation of agents’ doxastic states and a (axiomatically grounded) theory of decision which recognises and incorporates confidence in belief. Time-permitting, attitudes to choosing in the absence of confidence, applications and further directions will be discussed.

Speaker: Umberto Grandi
Title: Lifting Rationality Assumptions in Binary Aggregation
Date and time: Friday 25 June 2010, 16:00
Location: Room A1.04, Science Park 904, Amsterdam

Abstract

We consider problems where several individuals each need to make a yes/no choice regarding a number of issues and these choices then need to be aggregated into a collective choice. Depending on the application at hand, different combinations of yes/no may be considered rational. We can describe such rationality assumptions in terms of a propositional formula. The question then arises whether or not a given aggregation procedure will lift the rationality assumptions from the individual to the collective level, i.e., whether the collective choice will be rational whenever all individual choices are. To address this question, for each of a number of simple fragments of the language of propositional logic, we provide an axiomatic characterisation of the class of aggregation procedures that will lift all rationality assumptions expressible in that fragment. (This is joint work with Ulle Endriss.)

For more information, see http://www.illc.uva.nl/~ulle/seminar/ or contact Ulle Endriss (ulle.endrissuva.nl).