In 2020 the Environmental Protection Agency narrowed the definition of “waters of the United States,” significantly limiting wetland protection under the Clean Water Act. Current policy debates center on the uncertainty around wetland benefits. We estimate the value of wet-lands for flood mitigation across the United States using detailed flood claims and land use data. We find the average hectare of wetland lost between 2001 and 2016 cost society $1,840 annually, and over $8,000 in developed areas. We document significant spatial heterogeneity in wetland benefits, with implications for flood insurance policy and the 50 percent of “isolated ” wetlands at risk of losing federal protection. (JEL K32, Q24, Q25, Q53, Q58)

中文翻译：

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湿地、洪水和清洁水法

2020 年，环境保护署缩小了“美国水域”的定义，大大限制了《清洁水法》对湿地的保护。当前的政策辩论集中在湿地效益的不确定性上。我们使用详细的洪水索赔和土地利用数据估计了美国各地用于减轻洪水的湿地价值。我们发现 2001 年至 2016 年间平均每公顷湿地损失的社会成本为每年 1,840 美元，而发达地区则超过 8,000 美元。我们记录了湿地效益的显着空间异质性，对洪水保险政策和 50% 的“孤立”湿地有失去联邦保护的风险产生影响。(JEL K32、Q24、Q25、Q53、Q58)