13 March 2009, Computational Social Choice Seminar, Davide Grossi
In this talk I will investigate some interrelationships between the social-theoretic problems of preference and judgment aggregation from the perspective of logical semantics. On the one hand, preference aggregation will be shown to be equivalent to the aggregation of special types of judgments. On the other hand, the judgment aggregation problem will be proven equivalent to the aggregation of specific types of preferences. As a result, a detailed map of aggregation problems is obtained which highlights differences and similarities between the two research fields of preference and judgment aggregation, which allows the cross import of impossibility results between them, and which makes a unification of the two fields possible.