The Mortality and Medical Costs of Air Pollution: Evidence from Changes in Wind Direction
利用美国老年人医保数据，通过风向变化作为工具变量，估计了急性细颗粒物暴露对死亡率、医疗使用和成本的影响，发现约25%的老年人承担了大部分死亡风险。
We estimate the causal effects of acute fine particulate matter exposure on mortality, health care use, and medical costs among the US elderly using Medicare data. We instrument for air pollution using changes in local wind direction and develop a new approach that uses machine learning to estimate the life-years lost due to pollution exposure. Finally, we characterize treatment effect heterogeneity using both life expectancy and generic machine learning inference. Both approaches find that mortality effects are concentrated in about 25 percent of the elderly population.