Universal size effects for populations in group-outcome decision-making problems.
Elections constitute a paradigm of decision-making problems that have puzzled experts of different disciplines for decades. We study two decision-making problems, where groups make decisions that impact only themselves as a group. In both studied cases, participation in local elections and the number of democratic representatives at different scales (from local to national), we observe a universal scaling with the constituency size. These results may be interpreted as constituencies having a hierarchical structure, where each group of N agents, at each level of the hierarchy, is divided in about N(δ) subgroups with δ≈1/3. Following this interpretation, we propose a phenomenological model of vote participation where abstention is related to the perceived link of an agent to the rest of the constituency and which reproduces quantitatively the observed data.
Laboratoire de Physique Théorique et Modélisation, UMR-8089 CNRS-Université Cergy Pontoise, France.
Christian
C
Borghesi
Laboratoire de Physique Théorique et Modélisation, UMR-8089 CNRS-Université Cergy Pontoise, France.
Laura
L
Hernández
Institut de Physique Théorique, CEA-Saclay, France.
Rémi
R
Louf
Département Géographie, Centre Universitaire de Formation et de Recherche de Mayotte, France.
Fabrice
F
Caparros