The Problem of the Safety of the Agenda in Judgment Aggregation

Mercoledi' 26 Maggio 2010 - prof. Ulle Endriss


Mercoledi' 26 Maggio 2010, alle ore 14:30 in aula 2AB/45 il prof. Endriss (ILLC, University of Amsterdam) terra' un seminario, su uno dei suoi lavori piu' recenti e pubblicato ad AAMAS 2010 (9th International Conference on Autonomous Agents and Multiagent Systems) dal titolo "The Problem of the Safety of the Agenda in Judgment Aggregation".

Aggregating the judgments of a group of agents regarding a set of interdependent propositions can lead to inconsistent outcomes. This paradox of judgment aggregation has recently sparked a good deal of interest in Legal Theory, Philosophy, Economics, and Computer Science. I will start with a short introduction to judgment aggregation and then formulate a new problem in this context, the problem of the safety of the agenda (SoA). The agenda is the set of propositions on which the agents have to express an opinion, and SoA asks, for a given agenda, whether we can guarantee that judgment aggregation will never produce an inconsistent outcome for any aggregation procedure satisfying a given set of axioms. I will report on a number of characterisation results, establishing necessary and sufficient conditions for SoA to be satisfied for different combinations of the most important axioms proposed in the literature, as well as complexity results for deciding SoA. No domain-specific background knowledge will be required to follow the presentation.

This is joint work with Umberto Grandi and Daniele Porello.

Rif. int. F. Rossi