This paper estimates the short-run and long-run impacts of early childhood lead exposure from drinking water on educational outcomes, the spatial and demographic distribution of these impacts, and the welfare impacts of lead abatement policies. I merge data from the U.S. Environmental Protection Agency on lead violations under the Safe Drinking Water Act with data on individual standard test scores, educational attainment, and wages from restrictive-use Texas data. I also match lead concentration in drinking water with Blood Lead Levels (BLLs) data, education and labor-market outcomes for a subgroup of individuals for whom we can identify their drinking water provider in Texas to understand the dose-response impacts of lead in drinking water. I ﬁnd that lead exposure at birth from drinking water has signiﬁcant negative impact on students’ 3rd grade standard test scores. In the long run, it also signiﬁcantly reduce the high school graduation rate.
A more comprehensive estimate of the value of water quality
Prior work suggests that, unlike air pollution regulation, the marginal cost of ambient water pollution regulation in the United States often exceeds its marginal beneﬁt. This paper provides some intuition, theory and empirical evidence suggesting that the typical hedonic property model — a common revealed-preference approach in the literature valuing environmental amenities — may tend to understate MWTP for the improved recreational opportunities that better water quality aﬀords to local homeowners. Using the case of nutrient pollution in Tampa Bay, Florida, we estimate MWTP for water quality improvements by combining a recreation demand model with a hedonic housing model, allowing households to optimize over regional aquatic recreation opportunities (inﬂuenced by pollution in recreational waters) as well as ambient water quality very close to homes. Results indicate that homeowners have signiﬁcant MWTP for both improvements in local ambient water quality and improvements in regional recreational waters. Our recreational beneﬁt estimates are much larger than those we estimate for local amenity values, suggesting that prior hedonic studies may underestimate the value of water pollution control.
Suicide and Lithium in the Public Water Supply of 870 US Counties
Several studies have reported that suicide rates are lower in areas with higher concentrations of lithium in drinking water. Some authors have recommended adding lithium to the public water supply. We estimate the association between suicide and drinking-water lithium in the largest dataset yet used for this purpose. In 870 US counties, we regress county suicide rates on lithium concentrations in groundwater and surface water. We control for spatial correlation and county-level correlates of suicide rates, including economic conditions and religious, racial, and ethnic composition. With or without covariates, we ﬁnd no signiﬁcant association between county suicide rates and the concentration of lithium in the water supply. Our results do not support a policy of adding lithium to the water supply.
Works in Progress
Do River Chiefs Reduce Surface Water Pollution in China?
In 2016, the central government in China passed on new policy appointing local government oﬃcials as river chiefs across the country, making them responsible for water resource management. The river chief mechanism assigns each section of rivers and lakes in China with river chiefs by the end of 2018. Since the announcement of this new policy, an ongoing debate has begun on the possible eﬀectiveness of river chiefs in reducing pollution. In this paper, I contribute to the debate by empirically investigating the eﬀect of the River Chief Mechanism on water quality in China. I construct a data set combining surface water quality data from various sources in China and collect data on the dates each province and city make initial announcements of its river chiefs. An event study analysis is performed to understand the impact of river chief assignment on water quality.
Subway opening and air quality in China
Using data on subway openings and daily air quality in China from 2002-2017, we measure the impact of subway openings on air quality. Existing studies have linked subway openings to air quality improvements in both developed and developing countries. But some studies found heterogeneous impacts of subway openings in Chinese cities. This study adds to the literature by focusing on subway openings and extensions to all Chinese cities from 2002-2017. Using traﬃc congestion data, we also test for the mechanism that could explain the impacts of subway openings on air quality.