Computation of median orders: complexity results

Olivier Hudry (1)

1 ENST - Ecole Nationale Supérieure des Télécommunications

Given a set of individual preferences defined on a same finite set of candidates, we consider the problem of aggregating them into a collective preference minimizing the number of disagreements with respect to the given set and verifying some structural properties like transitivity. We study the complexity of this problem when the individual preferences as well as the collective one must verify different properties, and we show that the aggregation problem is NP-hard for different types of collective preferences, even when the individual preferences are linear orders.

Mots clés: Complexity; partially ordered relations; median relations; aggregation of preferences

Olivier Hudry. Computation of median orders: complexity results. pp.36, 2004. ⟨hal-00018369⟩