Policy, Risk, and Norms Shape Collective Behaviors Worldwide

Abstract

Societal responses to environmental change vary widely, even under comparable shocks, reflecting differences in both policy measures and public reactions shaped by cultural and socioeconomic contexts. We examine mask-wearing dynamics across 47 countries during the COVID-19 pandemic using a process-based, utility-driven model of individual behavior with three evolving drivers: policy stringency, disease risk, and social norms to understand emergent collective behavior. Calibrated with daily data on mask usage, COVID-19 deaths, and policy mandates, the model reproduces diverse national trajectories with minimal complexity. Policy and norms are crucial for explaining variation, and we find significant associations between weights for all three drivers and cultural and socioeconomic indicators. Our findings demonstrate how mechanistic models can uncover the processes shaping collective behavior, enabling policymakers to anticipate the magnitude and timing of behavioral change and design more effective, context-sensitive interventions.