清洁识别？《清洁空气法》对空气污染、暴露差异与房价的影响
Clean Identification? The Effects of the Clean Air Act on Air Pollution, Exposure Disparities, and House Prices
American Economic Journal: Economic Policy · 2025 · [{"name": "Lutz Sager", "affiliation": ["École Supérieure des Sciences Économiques et Commerciales"]}, {"name": "Gregor Singer", "affiliation": ["London School of Economics and Political Science"]}]
中文摘要
我们评估了美国《清洁空气法》关于细颗粒物（PM2.5）的标准。利用高分辨率数据，我们发现2005年的法规使PM2.5水平在五年内降低了0.4 μg/m³，且在污染更严重的地区效果更大。标准双重差分方法将这些效应高估了三倍，原因是时间趋势因基线污染水平不同而存在差异，我们通过三种替代方法克服了这一偏误。我们发现，该法规有助于缩小城乡之间以及黑人与白人之间的PM2.5暴露差距，但缩小幅度小于双重差分方法所暗示的程度。然而，在利用规制变异时，资本化进入房价的污染损害似乎大于以往认为的水平。（JEL D63, K32, Q52, Q53, Q58, R31）
Abstract
We assess the US Clean Air Act standards for fine particulate matter (PM 2.5 ). Using high-resolution data, we find that the 2005 regulation reduced PM 2.5 levels by 0.4 μg/m 3 over five years, with larger effects in more polluted areas. Standard difference-in-differences overstates these effects by a factor of three because time trends differ by baseline pollution, a bias we overcome with three alternative approaches. We show that the regulation contributed to narrowing Urban-Rural and Black-White PM 2.5 exposure disparities, but less than difference-in-differences suggest. Pollution damages capitalized into house prices, however, appear larger than previously thought when leveraging regulatory variation. (JEL D63, K32, Q52, Q53, Q58, R31)