Dissertation: Three Essays on the Economics of Water Quality in the United States
Committee: Robert Mendelsohn (Chair), Nicholas Muller, James Saiers
"Estimating the Effects of Nutrients on Water-Based Recreational Uses in the United States: An Instrumental Variables Approach" (Job Market Paper)
"An Integrated Assessment Framework to Measure the Damages from Water Pollution in the United States"
Although the U.S. spends tens of billions of dollars a year controlling water
pollution, there is little empirical evidence of comparable benefits.
This study argues that measurement error in national pollution data has caused
benefits to be underestimated. Using an instrumental variables approach,
the study shows that there are substantial benefits associated with reducing
nutrient pollution, especially phosphorus concentrations in freshwater
systems. Instrumental variable estimates of the effects of phosphorus on
recreational use are an order of magnitude larger than traditional
cross-sectional estimates. The study uses a carefully measured
state-level pollution dataset to show that this difference is consistent with
an estimate of measurement error in national water pollution data.
"The Effectiveness of Overlapping Pollution Regulation: Evidence from the U.S. Ban on Phosphate in Dishwasher Detergent"
Motivated by the ambitious goals of the Clean Water Act of 1972, economists
have put forth significant efforts to measure the economic damages of
water pollution in the United States. The prevailing approach in the
literature relies upon national stated preference surveys to estimate what
individuals are willing to pay for certain levels of water quality. These
estimates are often combined with a hydrologic model to measure the total
benefits of achieving substantial changes in water quality. Building upon
similar advances in integrated assessment models for air pollution, this paper
proposes a conceptual framework for an integrated assessment model that focuses
on recovering marginal damages of water pollution in the United States.
Potential sources of data and the main obstacles to build this type of model
(With Alex W. Cohen
The management of pollution is often complicated by a variety of policies set
within and across various levels of government. Recent work has shown
that differences in federal and state policies have critical consequences for
pollution control in the U.S. The contribution of this paper is to show
that important policy interactions also occur when pollution policies are left
uncoordinated within states. Our work explores the case of recent
state-level bans on phosphates in household dishwasher detergent. An
oft-cited objective of this legislation is to reduce phosphorus loadings to
waterways. Using a simple model of wastewater treatment behavior, we show
that the effectiveness of the ban critically depends upon existing pollution regulations.
In particular, when faced with a phosphorus emissions standard, facilities have
no incentive to further reduce emissions. We test our model using
facility, month level effluent pre- and post-ban to identify the effect of the
ban on facilities with and without phosphorus limits. We find that
phosphorus effluent concentration levels dropped 14.5 percentage points more at
no limit versus limit facilities as a result of the ban. As further
validation of our model, we estimate an elasticity of effluent concentration
with respect to influent concentration for a select group of facilities.
As expected, facilities without limits display a much greater response to
exogenous shocks to influent. These results reinforce the need for more
coordination in pollution policy design.