23 April 2010, Computational Social Choice Seminar, Umberto Grandi
Aggregating the judgments of a group of agents regarding a set of interdependent propositions can lead to inconsistent outcomes. One of the parameters involved is the agenda, the set of propositions on which agents are asked to express an opinion. In this talk, I will introduce the problem of checking the safety of the agenda: for a given agenda, can we guarantee that judgment aggregation will never produce an inconsistent outcome for any aggregation procedure satisfying a given set of axioms? I will then report on several characterisation results, establishing necessary and sufficient conditions for the safety of the agenda for different combinations of the most important axioms proposed in the literature, as well as on
complexity results for the problem of checking whether a given agenda satisfies these conditions.
This is joint work with Ulle Endriss and Daniele Porello.