中文摘要
如果环境规制缺乏合理设计的经济激励，或未能考虑污染者的应对行为，可能引发非预期的污染外部性。本文考察中国全面禁止秸秆焚烧（UPSB）政策的有效性及其非预期后果。利用广义双重差分设计，我们发现，UPSB政策通过自上而下的运动式执法，显著减少了农业火点和空气污染。然而，由于焚烧秸秆通常用于杀灭害虫和肥沃土壤，该政策也增加了化肥和农药的使用，从而加剧了水污染。成本收益分析表明，空气质量改善带来的大部分健康收益被水质恶化造成的健康成本所抵消。我们的发现凸显了在开展政策评估时考虑受规制个体潜在应对行为的重要性。• 本文考察中国秸秆焚烧规制的有效性及其非预期后果。• 我们发现，该政策通过自上而下的运动式执法，显著减少了农业火点，进而降低了空气污染。• 然而，由于焚烧秸秆通常用于杀灭害虫和肥沃土壤，秸秆焚烧规制政策也增加了化肥和农药的使用。• 该政策出乎意料地导致水污染加剧。• 成本收益分析表明，在将水污染的潜在后果纳入考虑后，该政策的成本超过其收益。
Abstract
Environmental regulations can trigger unintended pollution externalities if they lack well-designed economic incentives or fail to account for the responses of polluters. This paper examines the effectiveness and unintended consequences of the Universal Prohibition on Straw Burning (UPSB) policy in China. By exploiting a generalized difference-in-differences design, we find that the UPSB policy significantly reduces agricultural fires and air pollution through top-down campaign-style enforcement. However, as straw burning is commonly used to kill pests and fertilize the soil, the UPSB policy also increases the use of chemical fertilizers and pesticides, leading to magnified water pollution. Cost-benefit analysis suggests that much of the health benefit from improved air quality is offset by the health cost from degraded water quality. Our findings highlight the importance of considering the potential responses of individuals subject to the regulation when conducting policy evaluation. • This paper examines the effectiveness and unintended consequences of the straw burning regulation in China. • We find that the policy significantly reduces agricultural fires and thereby air pollution through top-down campaign-style enforcement. • However, as straw burning is commonly used to kill pests and fertilize the soil, the straw burning regulation policy also increases the use of chemical fertilizers and pesticides. • Unintendedly, the policy leads to increased water pollution. • Cost-benefit analysis suggests that, when taking the potential consequences of water pollution into account, the cost of the policy exceeds its benefit.