Workshop SNAAS (Social Network Analysis in Animal Societies)

Universality in systems with group-outcome decision making

Non programmé

25m

Auditorium (Collège Doctoral Européen, Strasbourg)

Présentation orale

Orateur

M. Christian Borghesi (LPTM --Laboratoire de Physique Théorique et Modélisation--, Université Cergy-Pontoise)

Description

We study decision making in two different situations, where a group of N agents makes a decision that concerns only themselves as a group. The first case, electoral data concerning participation to local elections in many countries, shows a universal scaling law as a function of the size, N, of each municipality. The second studied case, the number of democratic representatives for municipal, regional and national chambers in different countries, also exhibits a scaling behaviour as a function of the corresponding population, N. In both studied cases the corresponding group of $N$ agents behaves as if it were split into subgroups of the order of N^{1/3}. A simple phenomenological model reproducing the stylised facts of local elections is proposed.