2023-10-25-美联储-洪水风险图与气候信息的分布影响_95页_9mb

This study analyzes the impact of official flood risk information provision on residential flood insurance take-up in the United States, emphasizing distributional consequences. Key findings include:

• Flood maps updated post-Hurricane Katrina reduced the number of properties classified in high-risk floodplains, primarily in neighborhoods with higher shares of Black and Hispanic residents, despite increasing scientific evidence of rising flood risk.
• Map omissions, which favored predominantly minority neighborhoods, allowed residents to avoid higher insurance premiums and stricter regulatory requirements, exacerbating racial disparities in insurance coverage.
• Digital map access did not significantly affect insurance demand, but updates affecting floodplain classifications substantially changed take-up, with spillover effects suggesting both risk belief changes and mandatory purchase requirements influenced behaviors. Effects were stronger in neighborhoods with more minority residents, possibly due to higher price sensitivity.
• Overall, map updates led to a slight decrease in insurance coverage, primarily due to omissions, though this was masked by increased take-up in areas where properties were rezoned into high-risk zones.
• Welfare estimates indicate the divergence between official and independent flood risk information reduced consumer welfare by increasing information frictions. Correcting all flood maps to independent estimates could yield annual welfare gains exceeding $20 billion.
• These findings highlight how inadequate flood risk information can lead to mis-adaptation and disparities, notable even amidst ongoing climate change adaptation challenges.

The paper demonstrates a strong empirical case for revising flood mapping practices to reflect current flood science and distribute risk information equitably.