Ants, Rationality, and Recruitment

TLDR

Ants and humans both exhibit a tendency to cluster on one option before switching to another, a phenomenon observed in foraging and restaurant choice. The paper seeks to explain the puzzling switching behavior observed in ants and humans. The authors propose a simple stochastic recruitment model to capture the observed foraging dynamics. The model shows that herding and epidemic patterns in financial markets arise from the equilibrium distribution of a stochastic process, not from multiple equilibria.

Abstract

This paper offers an explanation of behavior that puzzled entomologists and economists. Ants, faced with two identical food sources, were observed to concentrate more on one of these, but after a period they would turn their attention to the other. The same phenomenon has been observed in humans choosing between restaurants. After discussing the nature of foraging and recruitment behavior in ants, a simple model of stochastic recruitment is suggested. This explains the “herding” and “epidemics” described in the literature on financial markets as corresponding to the equilibrium distribution of a stochastic process rather than to switching between multiple equilibria.