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Realized benefits from total wetland restorations since 2018 by nutrient level
Nature's Kidneys: the Role of the Wetland Reserve Easements in Restoring Water Quality with Dr. Marin Skidmore
Billions of dollars have been dedicated to mitigating non-point source pollutionfrom US agriculture. Wetlands provide an ex-post natural solution by filtering sed-iments and excess nutrients from the landscape. Quantifying the impact of wetlandeasements in the Wetland Reserve Program (WRP) and Agricultural ConservationEasement Program (ACEP) on water quality is critical for optimal fund allocationfor non-point source pollution abatement. We causally identify whether newly re-stored wetlands reduce nitrogen and phosphorus loads at the subwatershed levelin the Mississippi River Basin. Results show that wetland easements reduce am-monia and total Kjeldahl nitrogen concentrations in the local subwatershed as wellas downstream. A short-term increase in local phosphorus immediately followingrestoration likely reflects soil disturbance. While wetlands have no significant long-term impact on local phosphorus levels, downstream reductions are observed. Weestimate that this federal investment in natural infrastructure leads to lower treat-ment costs for local water systems.
Easement area and county-level indemnities for corn
Estimating the Effects of Easements on Agricultural Production
US crops face higher losses as destructive disasters such as droughts and floods become commonplace. The Natural Resources Conservation Service (NRCS) easement programs offer a voluntary adaptation strategy to improving agricultural resilience. Easements impact agricultural production directly by reducing planting on marginal land and indirectly by improving yields on surrounding cropland. I use national USDA data from the past three decades to build a county-level panel. I employ a regression model with two-way fixed effects to quantify how easement land share impacts yields, risk, as well as acres planted, failed, and prevented planted. A 100% increase in land share of wetland easements increases yields by 0.34%, 0.77% and 0.46% for corn, soybeans, and wheat. Easements improve yields by mitigating the effect of excess precipitation and extreme degree days. Wetland easements reduce soybean losses from excess moisture, heat, and disease by $3.59, $6.07, and $11.23 for each dollar of liability. I also find evidence of a slippage effect in which producers reduce soybean and wheat acreage but increase corn production. This work quantifies some of the ecosystem benefits of easement habitats, uncovers program externalities, and has policy implications for future NRCS funding and targeting decisions.
Regression discontinuity: change in yields after easement
Regression discontinuity: change in yields after easement
The Direct and Indirect Effects of Wetland Easements: Evidence from Fields in Wisconsin
Land conservation can enhance agricultural resiliency by reducing vulnerability to climate-related risks and shocks. Understanding the optimal prices and ecosystem services of conserving land is an important step towards climate-smart agriculture. I evaluate the costs and benefits in terms of agricultural production of a major conservation policy, the Natural Resources Conservation Services Wetland Reserve Program. Novel remote sensing data allows for the identification of wetland easement effects on agricultural yields at the field level. I estimate the opportunity cost of wetland easements by estimating the forgone yields of retiring land from production. Using ranking data and a regression discontinuity framework, I find that easements decrease yields by 83 bushels per acre for corn (56% of average yields) and 31 bushels per acre for soybeans (73% of average yields). Further, using a dynamic difference-in-differences approach that accounts for staggered treatment timing, I find evidence that easements benefit surrounding production within a few kilometers: corn yields increase by 3-4 bushels per acre. Easements have the largest spillover effects in areas with open fields, open water, and during extreme rain events. These results call for attention to the opportunity costs and beneficial externalities of land conservation programs.
Acres enrolled in the Conservation Reserve Program by program type and acreage enrollment cap.
Water Quality and the Conservation Reserve Program: Empirical Evidence from the Mississippi River Basin with Aaron Hrozencik, Marin Skidmore, and Andrew Rosenberg
Agricultural runoff is the primary source of water quality impairment in the United States. The Conservation Reserve Program (CRP), which pays landowners to remove their environmentally sensitive land from production and to implement conservation covers and practices, is to a large degree aimed at reducing erosion and nutrient runoff. We study how land share in CRP impacts nitrogen, phosphorus and ammonia concentrations in the Mississippi River Basin from 2000-2018. We leverage contract-level CRP data and recently harmonized water quality measurements to evaluate CRP effectiveness at the subwatershed-level. We use an instrumental variables approach that exploits variation in the national acreage cap to mitigate the endogeneity bias. We estimate that increasing landshare in CRP significantly reduces nutrient levels. These findings contribute to a broader understanding of CRP's role in improving water quality, with implications for conservation programs and agricultural policies. By emphasizing voluntary programs like CRP, policymakers can more effectively combat agricultural non-point source water pollution, reducing its environmental and economic impacts.
Number of producer-led watershed groups and grant dollars awarded in Wisconsin.
Can Farmer-led Initiatives Reduce Nonpoint Source Pollution? with Jeffrey Hadachek and Andrew Stevens
Nonpoint source pollution from agriculture is the leading cause of nutrient pollution in the US. This paper addresses whether localized, farmer-led programs can cost-effectively reduce nonpoint source pollution by increasing the adoption of agricultural conservation practices. We study this in the context of an innovative program in Wisconsin that incentivizes farmers to take collective leadership of improving water quality in their local watersheds. Using a shift-share instrumental variables design, we find that a 10 percentage point increase in farmer participation in these programs leads to a 0.03 mg/L reduction (14\%) in ambient phosphorus concentrations in local streams and rivers. We also show that farmer participation in local watershed programs causes an increase in the adoption of cover crops, conservation tillage, and more diverse crop rotations. Importantly, this localized approach achieves water quality and conservation improvements at a substantially lower cost than existing federal subsidy programs, demonstrating the potential for bottom-up approaches to address nonpoint source pollution in other contexts.
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