Seminar: P.Girard 2013-08-13

Speaker: Patrick Girard (Philosophy)
Topic: “Belief revision and the limit assumption: Tension between static belief and belief dynamics”
When: 2:30-3:30, Tuesday 13 August
Where: Room 5115, OGGB
Abstract:
…so there’s this assumption called the limit assumption which basically says that doxastic orders are well-founded. If you only consider beliefs as being static, the assumption is philosophically implausible. However, when you do belief change, than it becomes crucial for a lot of doxastic operations. Without it, you can’t be sure that revising a belief set returns a belief set. Which considerations is more important? Static or dynamic? I will try and explain what that all means.

Call for Participation for 5th Summer Workshop

The Centre for Mathematical Social Science (CMSS) is pleased to announce that its 5th Summer Workshop will be held at the University of Auckland from 10-11 December 2013. The CMSS is an inter-disciplinary research centre whose members include mathematicians, computer scientists, philosophers and economists. Information on the CMSS, and details of previous Workshops, can be found on our website: http://cmss.auckland.ac.nz/.

This year’s theme is mechanism design, but submissions on any aspect of mathematical social science are welcome.

Our 5th Workshop is co-hosted by the Energy Centre (EC) and Electric Power Optimisation Centre (EPOC) at the University of Auckland, and the Applied and Theoretical Economics (ATE) Network at Massey University. EC and EPOC will be organising a special session on the design of energy markets.

Confirmed speakers include:
Claudio Mezzetti (University of Melbourne)
Shmuel Oren (Berkeley) *Sponsored by the EC and EPOC*
Ludovic Renou (University of Essex)
Frank Wolak (Stanford University) *Sponsored by ATE and Massey University*

If you would like to submit a paper for the Workshop, please contact Matthew Ryan (m.ryan@auckland.ac.nz) for general sessions, or Golbon Zakeri (g.zakeri@auckland.ac.nz) for the special session on energy markets, by 15 October 2013. We will be glad to hear from you.
There is no fee for participating in the Workshop.

Participants may also be interested in the following event: the 1st ATE Symposium on the theme of “Competition Policy Issues: Theory Meets Practice” to be held at Massey University, Albany campus, on December 12-13. Details will be posted on the ATE website: http://ate.massey.ac.nz/.
Matthew Ryan Department of Economics University of Auckland

A seminar that may be of interest

Speaker:     Arkadii Slinko
Affiliation: University of Auckland
Title:       Clone Structures
Date:        Tuesday, 4 Jun 2013
Time:        14:00
Location:    303-412

In Economics, a set of linear orders is normally interpreted as a set of opinions of agents about objects in C.  Cloning candidates (products) is one of the most sophisticated tools of manipulation of elections (consumer surveys). Unfortunately most common voting rules are vulnerable to this method of manipulation. So clones do matter.

Mathematically, a subset of C which is ranked consecutively (though possibly in different order) in all linear orders is called a clone set. All clone sets for a given family of linear orders form the clone structure. In this talk I will formalise and study properties of  clone structures. In particular, I will give an axiomatic characterisation of clone structures, define the composition of those, classify irreducible ones, and show that it is sufficient to have only three linear orders to realise any clone structure.

This is a joint work with Piotr Faliszewski (Krakow) and Edith Elkind (Oxford).

All welcome!

Seminar: A. Slinko 2013-05-21

Speaker: Arkadii Slinko
Affiliation: The University of Auckland
Title: Secret sharing schemes 2 (elementary introduction)
Date: Tuesday, 21 May 2013
Time: 4:00 pm
Location: Room 6115, Owen Glenn Building

This is a continuation of my talk on 7 May 2013.

This time I will first introduce two large classes of ideal access structures, namely, conjunctive and disjunctive hierarchical access structures. They are characterised by the fact that users are divided into classes so that users within each class are equivalent but users belonging to different classes have different status with respect to the activity. For example, the UN Security Council with its permanent and non-permanent members is a conjunctive hierarchical access structure (to the passage of a resolution).

The main part of the talk will be focused on the connection between ideal secret sharing schemes and matroids. The theorem of Brickel and Davenport (1991) which describes this connection plays a central role in the theory of secret sharing. A short introduction to matroids will be given, no prior knowledge of matroids will be necessary.

Seminar: B. Klaus 2013-05-03

Speaker: Professor Bettina Klaus
Affiliation: University of Lausanne
Date: Friday 3 May 2013
Time: 12pm
Venue: Room 317, Level 3, Owen G Glenn Building

Abstract: In college admissions and student placements at public schools, the admission decision can be thought of as assigning indivisible objects with capacity constraints to a set of students such that each student receives at most one object and monetary compensations are not allowed. In these important market design problems, the agent-proposing deferred-acceptance (DA-)mechanism with responsive strict priorities performs well and economists have successfully implemented DA-mechanisms or slight variants thereof. We show that almost all real-life mechanisms used in such environments – including the large classes of priority mechanisms and linear programming mechanisms – satisfy a set of simple and intuitive properties. Once we add strategy-proofness to these properties, DA-mechanisms are the only ones surviving. In market design problems that are based on weak priorities (like school choice), generally multiple tie-breaking (MTB) procedures are used and then a mechanism is implemented with the obtained strict priorities. By adding stability with respect to the weak priorities, we establish the first normative foundation for MTB-DA-mechanisms that are used in NYC.

This is a joint Department of Economics/CMSS seminar.