Conference Agenda

This paper evaluates the impact of upgrading wastewater discharge standards for wastewater treatment plant (WWTPs) in China using a novel dataset linking policies, WWTPs, and water quality monitors via hydrological topology. Employing a difference-in-differences approach, we find that the policy tightens implemented standards by 1.1%–4.0%, resulting in significant reductions in effluent COD (4.1%) and NH3-N (6.7%) through improved removal efficiency, albeit with higher operational costs. We show that such firm-level compliance hinges on ownership structure and pipeline infrastructure. This micro-level abatement effectively translates into downstream water quality improvements, evidenced by a 0.328 improvement in the Water Quality Index, a 22.3% reduction in riverine NH3-N, and an approximately 40% surge in Dissolved Oxygen. This transmission is characterized by a 10-14 month time lag and spatial decay. Furthermore, these environmental benefits are heterogeneous across river sections, depending on administrative border incentives, environmental capacity, and baseline pollution levels.

This paper quantifies the effect of oil spills on local economic development in Nigeria. We assemble a geo-referenced panel of more than 13,000 oil spills and merge them with satellite indicators of economic activity, poverty, vegetation condition, and migration. We develop a hydrological model that traces downstream contaminant transport, allowing spill exposure to extend beyond the point of discharge. To address endogeneity, we instrument hydrologically defined exposure with the interaction of global oil-price shocks and historical transport costs. Relative to comparable cells, spill-exposed cells exhibit a 7.2-unit decline in night-time lights, an 8.9 percentage-point rise in unlit settlements, and 29 additional residents per 1,000 without electricity. Potential mechanisms include environmental degradation, with a 0.08 km² annual acceleration in deforestation and a 0.43-point decline in NDVI, and a net out-migration of 76 people per 1,000 (per cell-year). Dynamic event-study estimates show that these effects intensify from four to twelve years post-spill.

This paper studies the water consumption choices of households in response to policy interventions by a water utility. We specifically study the effects of home visits and billing changes, and estimate the water-saving effects from information, technology and prices. Home visits consist of information provision (information) and the installation of water-saving devices (technology). Billing changes migrate households from flat fees to variable fees (price). Using a staggered difference-in-differences approach we disentangle the three effects. We find a statistically significant effect from home visits (technology and information) on water savings of about 10%. Interestingly, this effect is persistent. Devices (technology) installed in the shower and toilet are most effective for saving water. Billing changes (price) result in more water savings for households with higher baseline water consumption. Households in the first two quintiles see no effect, while households in the highest quintile reduce water consumption by about 8%.

This study estimates the effectiveness of the U.S. Department of Agriculture's Environmental Quality Incentives Program (EQIP) cover crop subsidies to mitigate water pollution from agricultural runoff and leaching. The study uses a novel satellite-derived dataset of field-level cover crop adoption and exploits quasi-experimental variation from the geographically and temporally varying implementation of EQIP's Mississippi River Basin Healthy Watersheds Initiative (EQIP-MRBI). Event-study results indicate that MRBI funding increases cover crop adoption by 34% relative to baseline, with persistent effects. Linking satellite adoption data to water-quality records, the study finds that a one-percentage-point increase in upstream adoption reduces total nitrogen by 0.83%. The implied benefit-cost ratio is 2.52.