Mathematical model of normative decision-making and its empirical analysis during and after the COVID-19 pandemic

Abstract

Objectives: Social norms are crucial for understanding and explaining human social behavior. Studying such behavioral factors will contribute to the social implementation of nudges. Researchers have investigated COVID-19 preventive behaviors. This paper explains the Focus Theory of Normative Conduct and its mathematical model and analyses voluntary restraint against going out during the COVID-19 and post-pandemic periods. The Focus Theory of Normative Conduct posits that behavior is determined by whether an individual focuses on the aspect of the behavior that satisfies descriptive norms, i.e., norms based on the perception of what most people are doing, or injunctive norms, i.e., norms based on the perception of what others in the group believe an individual should do. Methods: We conducted web surveys in 2021 and 2023, focusing on COVID-19-related decision-making scenarios. We estimated parameters related to the decision-maker's attention using a mathematical model of the focus theory of normative conduct and compared these parameters across the survey years. This comparison enabled us to use a mathematical decision-making model to examine how people's attention to injunctive and descriptive norms changed during the COVID-19 and post-pandemic periods. Results: Including information about “variants” in messages advising against non-essential outings increased the likelihood of people avoiding going out and heightened their attention to injunctive norms. Furthermore, the comparative analysis between the survey years indicated a trend where attention to injunctive norms became more pronounced post-pandemic than during the pandemic. Conclusion: The increased attention to injunctive norms suggests that individuals chose to refrain from going out more due to the belief that they should avoid non-essential outings (injunctive norm) rather than because others were doing so (descriptive norm). This study indicates that incorporating information about “variants” in messages would emphasize the belief that non-essential outings should be avoided. Additionally, this tendency was stronger post-pandemic than during the pandemic.