Speaker: Omer Lev The Hebrew University Date: Monday, 22 December 2014 Time: 12noon Place: Rothberg A410 ======= "The Big Equilibria Cull: Advances in the effort to make Nash equilibria relevant for voting games" Abstract: The Gibbard-Satterthwaite theorem means we cannot assess voting rules according to the results they provide on a truthful set of preferences, as people will have an incentive to misreport their beliefs. The most natural solution concept in this situation, Nash equilibrium, turns out to be mostly useless in voting scenarios, as there are far too many of those, many of them senseless. In the past few years several ideas have been suggested to try and make the Nash equilibrium a useful concept, enabling more robust analysis of voting rules, which better resemble real-life situations and allow for both empirical and theoretical work. The talk will touch on the main ideas in this line of research: truth-biased voters, lazy-biased voters and iterative voting dynamics. It will further discuss the combination of these, along with the most recent work relaxing the requirement for full-information models (i.e., all voters no longer need to know exactly how everyone else is voting). In most cases, both theoretical and empirical results will be presented. The work presented here is from several papers with various collaborators: David R.M. Thompson, Kevin Leyton-Brown, Reshef Meir, Zinovi Rabinovich, Svetlana Obraztsova, Evangelos Markakis and Jeffrey S. Rosenschein. =======