Journal of Human Resources · 2022 · Alex Hollingsworth、Jiafang Mike Huang、Ivan Rudik、Nicholas Sanders
中文摘要
我们利用一项自然实验研究环境铅暴露如何影响小学阶段的学习：在该实验中，一个大型全国性汽车竞速组织将含铅燃料改为无铅燃料。我们发现，铅暴露水平上升和暴露持续时间延长会对学业表现产生负面影响，使整个学业表现分布发生偏移，并对年龄较小和较大的儿童均产生负面影响。在本文的研究情境下，受处理学生的预期收入平均减少现值5,200美元。避免受到上述处理的效应量，相当于教师增值提高四分之一个标准差、班级规模减少3名学生，或生均学校支出增加750美元。铅的边际影响在贫困县和非白人县更大，在暴露持续时间更长的学生中也更大——即使控制了暴露总量之后依然如此。
Abstract
Abstract We study how ambient lead exposure impacts learning in elementary school by leveraging a natural experiment where a large national automotive racing organization switched from leaded to unleaded fuel. We find increased levels and duration of exposure to lead negatively affect academic performance, shift the entire academic performance distribution, and negatively impact both younger and older children. The average treated student in our setting has an expected income reduction of $5,200 in present value terms. Avoiding said treatment has an effect size similar to improving teacher value added by one-fourth of a standard deviation, reducing class size by 3 students, or increasing school spending per pupil by $750. The marginal impacts of lead are larger in impoverished, non-white counties, and among students with greater duration of exposure, even after controlling for the total quantity of exposure.