Sém. 18/05/17 M. Gori


10h45 - 12h00

Salle de réunion 009 GATE Lyon Saint-Etienne
10, Rue Tréfilerie
42023 Saint Etienne Cedex 2

Campus Tréfilerie - GATE LSE - Maison de l'Université Bâtiment B

Michele Gori, University of Florence présentera un séminaire intitulé : The flow network method.

Thème de recherche / Main topics : Social Choice, Network, Tournament, Multiwinner Voting Systems.

Résumé / abstract  : In this paper we propose an in-depth analysis of a method, called the flow network method, which associates with any network a complete and quasi-transitive binary relation on its vertices. Such a method, originally proposed by Gvozdik (1987), is based on the concept of maximum flow. Given a competition involving two or more teams, the flow network method can be used to build a relation on the set of teams which establishes, for every ordered pair of teams, if the first one did at least as good as the second one in the competition. Such a relation naturally induces procedures for ranking teams and selecting the best k teams of a competition. Those procedures are proved to satisfy many desirable properties. Further, by means of the flow network method, we define a multiwinner voting system where individuals are allowed to express their preferences through any binary relation on the set of alternatives. That system is proved to be decisive, anonymous, neutral, homogeneous, unanimous, monotonic and immune to the reversal bias as well as to coincide with the multiwinner Borda count for preference profiles made up by linear orders. The theory here developed also allows to get an interesting characterization of complete and quasi-transitive relations.

Co-authors : Daniela Bubboloni

Michele Gori

The flow network method