Collective Decision Dynamics in the Presence of External Drivers

TL;DR

This paper presents models of how individuals in a network decide to evacuate during a disaster, influenced by social interactions and external broadcasts, revealing how network structure and information type affect collective action.

Contribution

It introduces a comprehensive framework combining external influence and social interactions to analyze decision dynamics in networks during emergencies.

Findings

Social networks promote clustering and cohesive actions.

Binary information causes high variability and stagnation.

Network transmission can either promote or hinder action depending on external influence.

Abstract

We develop a sequence of models describing information transmission and decision dynamics for a network of individual agents subject to multiple sources of influence. Our general framework is set in the context of an impending natural disaster, where individuals, represented by nodes on the network, must decide whether or not to evacuate. Sources of influence include a one-to-many externally driven global broadcast as well as pairwise interactions, across links in the network, in which agents transmit either continuous opinions or binary actions. We consider both uniform and variable threshold rules on the individual opinion as baseline models for decision-making. Our results indicate that 1) social networks lead to clustering and cohesive action among individuals, 2) binary information introduces high temporal variability and stagnation, and 3) information transmission over the network can either facilitate or hinder action adoption, depending on the influence of the global broadcast relative to the social network. Our framework highlights the essential role of local interactions between agents in predicting collective behavior of the population as a whole.