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arXiv · 1305.5476

Universal size effects for populations in group-outcome decision-making problems

Christian Borghesi·Laura Hernández·Rémi Louf·Fabrice Caparros
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Abstract

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 $δ\approx 1/3$. 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.

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Christian Borghesi, Laura Hernández, Rémi Louf, Fabrice Caparros. 2014-01-20. Universal size effects for populations in group-outcome decision-making problems. https://doi.org/10.1103/physreve.88.062813

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