中文摘要
已有文献表明，空气污染可能对生理和认知表现产生短期与长期的不利影响。本研究估计污染水平上升对建筑工地事故发生概率的影响，此类事故是导致劳动力市场生产率损失的重要因素。利用以色列所有建筑工地和污染监测站的数据，我们发现，作为主要空气污染物之一的二氧化氮（NO2）对建筑工地事故存在强烈且统计显著的因果效应。我们发现，NO2浓度每上升10 ppb，事故发生概率最多增加25%。重要的是，我们的研究结果表明这些效应是非线性的：根据美国环保署（EPA）标准，与清洁空气水平相比，中度污染水平使事故发生概率增加138%，不健康水平则使其增加377%。我们提出一种机制，即在认知负荷较高或警觉性降低的条件下，污染的影响会加剧。最后，我们开展成本收益分析，并以非参数估计计算的、归因于NO2暴露的隐含事故数量作为支持，同时考察一项可能改善福利的政策，即在污染严重的日子补贴建筑工地停工。
Abstract
Literature has shown that air pollution can have short- and long-term adverse effects on physiological and cognitive performance. In this study, we estimate the effect of increased pollution levels on the likelihood of accidents at construction sites, a significant factor related to productivity losses in the labor market. Using data from all construction sites and pollution monitoring stations in Israel, we find a strong and significant causal effect of nitrogen dioxide (NO 2 ), one of the primary air pollutants, on construction site accidents. We find that a 10-ppb increase in NO 2 levels increases the likelihood of an accident by as much as 25 %. Importantly, our findings suggest that these effects are non-linear. While moderate pollution levels, according to EPA standards, compared to clean air levels, increase the likelihood of accidents by 138 %, unhealthy levels increase it by 377 %. We present a mechanism where the effect of pollution is exacerbated under conditions of high cognitive strain or reduced awareness. Finally, we perform a cost-benefit analysis, supported by a nonparametric estimation calculating the implied number of accidents due to NO 2 exposure, and examine a potential welfare-improving policy to subsidize the closure of construction sites on highly polluted days.