Dear all,
The next Computational Social Choice Seminar at the ILLC will take place
this Friday. Suzanne Bloks will speak about the work she did for her
Master's thesis on Condorcet winning sets at the London School of
Economics, before joining the ILLC a month ago. The abstract is included
below.
As always, for more information on the COMSOC Seminar, please consult
https://staff.science.uva.nl/u.endriss/seminar/.
All the best,
Ulle
-------------------------------------------------------------------------
Speaker: Suzanne Bloks (ILLC)
Title: Minimum-sized Condorcet Winning Sets in Preference Profiles
Date: Friday 3 May 2019
Time: 16:00
Location: Room F1.15, Science Park 107, Amsterdam
Abstract
This talk approaches an open question in Computational Social Choice
Theory, posed by Elkind, Lang and Saffidine in 2015: Do there exist
preference profiles in which the minimum size of a Condorcet winning set
is bigger than 3? A Condorcet winning set is a generalization of the
Condorcet winner. A set Y is a Condorcet winning set if for every
candidate z not in Y a majority of voters prefer some candidate in Y to
z. Elkind, Lang and Saffidine have constructed a preference profile in
which the minimum size of a Condorcet winning set is 3. That is, there
is no Condorcet winner or a Condorcet winning set of size 2 in the
constructed profile. It remains an open question whether preference
profiles can be constructed with minimum Condorcet winning sets of size
4 or higher. In this talk, we will explore this question by relating
Condorcet winning sets in preference profiles to dominating sets in
tournaments. The concept of dominating sets in tournaments is related to
but stronger than the concept of Condorcet winning sets in preference
profiles. We will use this relation to make advancements towards
constructing preference profiles with Condorcet dimension 4 or higher.
--
Ulle Endriss
ILLC, University of Amsterdam
http://www.illc.uva.nl/~ulle/
Dear all,
The next the Computational Social Choice Seminar at the ILLC will take
place this Friday. Our speaker is Daan Bloembergen from the CWI and he
will talk about recent work on liquid democracy. Full abstract below.
As always, for more information on the COMSOC Seminar, please consult
https://staff.science.uva.nl/u.endriss/seminar/.
All the best,
Ulle
-------------------------------------------------------------------------
Speaker: Daan Bloembergen (CWI)
Title: On Rational Delegations in Liquid Democracy
Date: Friday 5 April 2019
Time: 16:00
Location: Room F1.15, Science Park 107, Amsterdam
Abstract: This talk consists of two parts. In the first part, I will
present our recent paper that was published at AAAI'19, titled "On
Rational Delegations in Liquid Democracy". Liquid democracy is a proxy
voting method where proxies are delegable. In the paper we propose and
study a game-theoretic model of liquid democracy to address the
following question: when is it rational for a voter to delegate her
vote? We study the existence of pure-strategy Nash equilibria in this
model, and how group accuracy is affected by them. We complement these
results by means of simulations to study the effect of network
structures on group's accuracy, and various aspects of the patterns of
delegations that emerge in this type of interaction. In the second part,
I will sketch a brief and high-level overview of my main area of
research, which focuses on multi-agent reinforcement learning.
--
Ulle Endriss
ILLC, University of Amsterdam
http://www.illc.uva.nl/~ulle/
