The near-miss effect in flood risk estimation: A survey-based approach to model private mitigation intentions into agent-based models

Behavioral reactions to natural hazards, including floods, and mitigation intentions are strongly predicted by risk perception. Among the different psychological processes forging individuals’ risk-estimation, the present work focuses on the near-miss effect, the human tendency to underestimate the risks when a previous negative outcome is avoided by chance. Study 1 (N = 241) investigates the near-miss effect among residents of both flood-prone and safe areas, showing that participants exposed to near-miss scenarios perceive a lower level of risk and damages regardless of their past experience with the hazard, and thus are less prone to adopt protective measures. Based on the data collected in Study 1, Study 2 develops a series of agent-based models to simulate the effect of experiencing near-miss events on a neighborhood in a flood-prone area, where inhabitants have to decide whether to purchase insurance against flood-related damage. The agent-based models integrating the psychological parameters reveals that the underestimation of the likelihood of flooding due to the near-miss effect is likely to increase the negative economic consequences of disasters suffered by the population. The work shows, at a population level, how psychological factors and human responses to risk might tailor the economic consequences of flood-related events. Implications for risk management and communication are discussed.