Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305;
Woods Institute for the Environment, Stanford University, Stanford, CA 94305.
Proc Natl Acad Sci U S A. 2021 Apr 27;118(17). doi: 10.1073/pnas.2003374118.
Floods and other climate hazards pose a widespread and growing threat to housing and infrastructure around the world. By reflecting climate risk in prices, markets can discourage excessive development in hazardous areas. However, the extent to which markets price these risks remains poorly understood. Here we measure the effect of information about flood risk contained in regulatory floodplain maps on residential property values in the United States. Using multiple empirical approaches and two decades of sales data covering the universe of homes in the United States, we find little evidence that housing markets fully price information about flood risk in aggregate. However, the price penalty is larger for commercial buyers and in markets where buyers are more risk aware, suggesting that policies to improve risk communication could influence market outcomes. Our findings indicate that houses in flood zones in the United States are currently overvalued by a total of $43.8 billion (95% confidence interval: $32.6 to $55.6 billion) based on the information in publicly available flood hazard maps alone, raising concerns about the stability of real estate markets as climate risks become more salient and severe.
洪水和其他气候灾害对全球住房和基础设施构成了广泛且日益严重的威胁。通过在价格中反映气候风险,市场可以抑制危险地区的过度开发。然而,市场对这些风险的定价程度仍了解甚少。在这里,我们衡量了监管洪泛区地图中包含的洪水风险信息对美国住宅物业价值的影响。我们使用多种经验方法和涵盖美国所有房屋的二十年销售数据,发现几乎没有证据表明住房市场总体上充分对洪水风险信息进行定价。然而,对于商业买家和风险意识更强的市场,房价惩罚更大,这表明改善风险沟通的政策可能会影响市场结果。我们的研究结果表明,仅根据公开的洪水灾害地图上的信息,美国洪水区的房屋目前被高估了总计 438 亿美元(95%置信区间:326 亿至 556 亿美元),这引发了人们对房地产市场稳定性的担忧,因为气候风险变得更加明显和严重。