In this paper we explore the relationship between norms of belief revision that may be adopted by members of a community and the resulting dynamic properties of the distribution of beliefs across that community. We show that  at a qualitative level many aspects of social belief change  can be obtained from a very simplistic model, which we call `threshold influence’. In particular, we focus on the question of what makes the beliefs of a community stable under various dynamical situations. Besides, we  consider refinements and alternatives to the `threshold’ model. The most significant alternative is to move to consideration of plausibility judgements rather than mere beliefs. We show first that some such change is mandated by difficult problems with belief-based dynamics related to the need to decide on an order in which different beliefs are considered. Secondly, we show that the resulting plausibility-based account results in a dynamical system that is non-deterministic at the level of beliefs. Nonetheless, the plausibility-based account lacks certain intuitively desirable features, such as the preservation of the transitivity.

Ceteris Paribus clauses in reasoning are used to allow for defeaters of norms, rules or laws, such as in von Wright’s example “I prefer my raincoat over my umbrella, everything else being equal”. I offer an analysis in which sets of formulas S, embedded in modal operators, provide necessary and sufficient conditions for things to be equal in ceteris paribus clauses. I’ll talk about how ceteris paribus preferences can be formalised and discuss questions that arise with the formalisation, and propose some solutions.

In this talk I will outline the issues under consideration in the current review of the MMP voting system and outline the major options that can be chosen. I will try to explain the rational and major trade-offs made in the design of hybrid systems like MMP. From this point we will start a discussion on particular issues. This will hopefully start the process of preparation of a submission to the Electoral Commission on behalf of the Centre.

We will have a small informal workshop on epistemic logic, game theory, and related topics.  This time, emphasized topics are: Epistemic, cognitive aspects of game theory, and human behavior in social context. Methods are: philosophical, theoretical, experimental and simulation studies.

See the workshop website for more details. Submission deadline for abstracts is 25 May 2012 and the workshop is 27-30 August.

http://staff.science.uva.nl/~stephane/coopmas12/

Workshop co-located with AAMAS-2012
Valencia, Spain
June 4th or 5th, 2012

**Key dates**

* Submission of contributions: February 28th 2012
* Acceptance notification: March 27th 2012
* Workshop: June 4th or 5th, 2012

*Submission Instructions*

Submission must follow the Springer LNCS format and should be a maximum of 15 pages.

Papers must be submitted in PDF through easychair:

http://www.easychair.org/conferences/?conf=coopmas2012

*Aims and Focus*

The use of cooperative game theory to study how agents should cooperate and collaborate, along with the related topic of coalition formation, has received growing attention from the multiagent systems, game theory, and electronic commerce communities.

The workshop is intended to focus on topics in cooperation in multi-agent systems, cooperative game theory and cooperative solution concepts, formation of coalitions, negotiation between agents, joint decision making, and voting. We encourage submission of papers describing original or recently published work (in venues that are not typically attended by AAMAS participants, i.e., conferences other than AAMAS/AAAI/IJCAI). We also encourage submission of full version of short papers accepted at AAMAS. Topics of interest include, but are not limited to:

* Cooperative game theory
* Coalition formation
* Joint decision making and voting
* Representation issues
* Negotiation
* Collaborative filtering
* Market and economics based cooperation
* Interact with humans (negotiation / collaboration)

The workshop should be of interest to researchers in cooperative game theory and coalition formation, as well as to those who examine collaboration between agents, cooperation in multiagent systems and design and implement collaborating agents. We also welcome participants who are interested in applications of cooperative game theory, which include trading agents, sponsored search and recommender systems.

*Program Committee*
Confirmed PC members (to be completed)
* Haris Aziz (Technische Universität München, Germany)
* Georgios Chalkiadakis (Technical University of Crete, Greece)
* Piotr Faliszewski (AGH University of Science and Technology, Poland)
* Gianluigi Greco (University of Calabria, Italy)
* Kate Larson (University of Waterloo, Canada)
* Tomasz Michalak (University of Warsaw, Poland)
* Maria Polukarov (University of Southampton, United Kingdom)
* Ariel Procaccia (Carnegie Mellon University, United States)

*Workshop Organizers*

* Stéphane Airiau (University of Amsterdam, The Netherlands)
* Yoram Bachrach (Microsoft Research, Cambridge United Kingdom)
* Edith Elkind (Nanyang Technological University, Singapore)

* Lirong Xia (CRCS, Harvard University, United States)

At least 2 positions available for researchers on the interface of optimization, social choice
and machine learning.
Competitive Salary: 85K-110K Australian, incl. superannuation.
Duration: Up to 3 years in the first instance.
Research project: Optimisation, Preferences and Mechanism Design in Social Networks.

NICTA (National ICT Australia) is Australia’s Information and
Communications Technology (ICT) Research Centre of Excellence. Our
primary goal is to conduct world-class research generating fundamental
scientific results with an impact on society. NICTA aspires to be one
of the world’s top ten ICT research centres by 2020.

Applications are invited for researcher positions within the
Optimisation Research Group, to work with Toby Walsh and other
members of the group in Sydney.

We seek outstanding researchers who have recently received their PhD
to be part of a large, world-class optimisation group. The researchers
will join a new research project on the interface of the optimisation,
machine learning, and social networks. Social networks
are transforming the way that people and businesses interact.
However, they throw up many challenging new optimisation problems.
How do we best combine the preferences of multiple users? How do
best learn these preferences? How do we design mechanisms that use
these preferences which encourage truthful behaviour yet generate
outcomes which are (close to) optimal? Can we exploit the structure
of the social network?

Candidates should have a PhD in computer science, computational aspects
of economics, operations research, or related areas, with
a strong background in artificial intelligence, social choice,
operations research, machine learning or mechanism design. Candidates
should have a strong theoretical background, as well as programming
skills and experience in using optimisation technologies.

It is expected that all researchers will continue to build upon their
international reputation by publishing papers and attending top
conferences, while participating in projects at NICTA.

Application Instructions

The full text of the advertising will appear shortly.

Application Instructions

Please email resume, motivation letter, short research statement, and names of 3 referees to:

Toby Walsh (toby.walsh@nicta.com.au)

We focus on syntactic aspects of differential awareness that give rise to contractual disputes. Boundedly rational parties use a common language, but do not share a common understanding of the world, leading to ambiguity in both syntactic and semantic forms. In contractual relationships, ambiguity leads to disagreement and disputes. We show that the agents may prefer simpler less ambiguous contracts when facing potential disputes. In particular, parties may prefer liquidated damages provisions to contractual terms that specify a more complex risk allocation.

Everyone welcome!

Thirteenth ACM Conference on Electronic Commerce (EC’12)
June 4-8, 2012, Valencia, Spain

http://www.sigecom.org/ec12/

This conference includes areas of interest to CMSS members, such as  Computational Social Choice, Preferences and Decision Theory. Invited speakers for the 3rd CMSS summer workshop, Edith Elkind and Jerome Lang, are senior programme committee members.

• Edith Elkind (Nanyang Tech, Singapore)
• Piotr Faliszewski (AGH Krakow, Poland)
• Jerome Lang (University of Paris 9, France)
• Toby Walsh (University of NSW and NICTA, Australia)

This paper considers statistical inference when the prior takes the form of a belief function (Dempster, 1967; Shafer, 1976) rather than a probability. We review some approaches to this non-standard inference problem and discuss their properties.  The paper also develops an economic application, in which entrepreneurs learn about a new market or technology over time.  We demonstrate that these learning dynamics, when embedded in an equilibrium model of price determination, can produce an “investment bubble”: a boom in investment despite unfavourable market data – a frequentist evaluation would lead one to reject the new technology – followed by the inevitable crash.  The investment boom and bust in tech stocks of the late 1990′s is a recent example of the phenomenon. Curiously, the initial boom is driven not by the increasing exuberance of over-optimistic entrepreneurs, but by the diminishing resistance of their more conservative employees and financiers. This is a Joint work with Luca Rigotti (Pittsburgh) and Rhema Vaithianathan.

Everyone welcome!