中文摘要
经济活动对环境的影响并不限于直接作用于人类的影响。本文使用一个新颖的数据集，就经济活动与生态系统衰退之间的联系提供了新的证据，该数据集汇集了1960年至2015年间美国数万个地点的纵向生态抽样信息。经济活动的局部冲击，例如由全国性军事扩张所驱动的冲击，导致物种丰度、多样性和稳定性显著下降，其中观测到的效应有三分之一可由空气污染的因果影响解释。政府环境规制显著减轻了污染外部性。• 我们利用全国性军事扩张冲击作为准外生变异，首次对经济活动如何降低不同生物类群的生态系统生物多样性进行了因果估计。• 我们的分析利用了BioTIME数据库中的数百万条生态观测，使我们能够构建1960年至2015年美国各地物种丰度、丰富度和稳定性的纵向指标。• 我们将空气污染识别为一个关键的因果渠道；采用上风向污染工具变量策略的结果表明，空气污染解释了经济冲击对生物多样性影响的约三分之一。• 《清洁空气法》等环境规制显著减轻了生物多样性损失，这表明保护人类健康的经济政策也会带来巨大的生态协同效益。
Abstract
The environmental impacts of economic activities extend beyond those directly affecting humans. This paper provides new evidence on the link between economic activity and ecosystem decline using a novel dataset that compiles longitudinal ecological sampling information at tens of thousands of locations across the United States between 1960 and 2015. Local shocks in economic activities, such as those driven by national military buildups, led to a significant reduction in species abundance, diversity, and stability, with one-third of the observed effects explained by the causal impact of air pollution. Government environmental regulations significantly mitigated pollution externalities. • We provide the first causal estimates of how economic activity reduces ecosystem biodiversity across taxa, using national military buildup shocks as quasi-exogenous variation. • Our analysis leverages millions of ecological observations from the BioTIME database, which allow us to construct longitudinal measures of species abundance, richness, and stability across the U.S. from 1960 to 2015. • We identify air pollution as a key causal channel, showing it accounts for about a third of the biodiversity impact from economic shocks using an upwind pollution IV strategy. • Environmental regulations such as the Clean Air Act significantly mitigate biodiversity losses, suggesting economic policies that protect human health also confer large ecological co-benefits.