@article{swanson2024carbon,
  title={The Economic and Policy Challenges of Climate-Smart Agriculture},
  author={Smith, Aaron and Swanson, Andrew},
	url={https://files.asmith.ucdavis.edu/soil_carbon_draft.pdf},
	abstract={Climate-smart agriculture promises to mitigate climate change by sequestering carbon in soils on working lands. However, this promise faces substantial policy challenges due to heterogeneity, costly measurement, and uncertainty. We summarize the latest scientific literature on carbon sequestration in agricultural soils, and we describe the current policy environment. With that background, we present an economic framework for policy analysis. We conclude by emphasizing (i) the need for better measurement and policy that is robust to poor measurement, and (ii) the importance of improving agricultural productivity to avoid future carbon losses from expanded agricultural land use.},
	keywords={agriculture},
  year={2024}
}

Climate-smart agriculture promises to mitigate climate change by sequestering carbon in soils on working lands. However, this promise faces substantial policy challenges due to heterogeneity, costly measurement, and uncertainty. We summarize the latest scientific literature on carbon sequestration in agricultural soils, and we describe the current policy environment. With that background, we present an economic framework for policy analysis. We conclude by emphasizing (i) the need for better measurement and policy that is robust to poor measurement, and (ii) the importance of improving agricultural productivity to avoid future carbon losses from expanded agricultural land use.

@article{metaxogolou2022waterlegacy,
  title={Agriculture's Nitrogen Legacy},
  author={Metaxogolou, Konstantinos and Smith, Aaron},
	url={https://files.asmith.ucdavis.edu/water_draft_legacy.pdf},
	abstract={Nitrogen pollution of waterways is a large global problem, especially in regions with intensive cropland agriculture such as the Mississippi River Basin that drains 40\% of the continental United States. In contrast to prior studies, which mostly apply agronomic and hydrologic models, we collect detailed data from water quality monitors and use panel data econometric methods to estimate how land use affects nitrogen pollution. We find a strong positive effect of corn acreage on nitrogen concentration in nearby streams and rivers that is an order of magnitude smaller than those implied by the agronomic and hydrologic models. Our findings are consistent with a new line of research documenting accumulation of large amounts of nitrogen in subsurface soil and groundwater over several decades; this is excess nitrogen that was applied to fields but has yet to appear in waterways. This legacy nitrogen will eventually leach into streams and rivers exacerbating further nutrient pollution. In the presence of large amounts of legacy nitrogen, land retirement and other on-farm mitigation policies are uneconomic. Downstream off-farm practices, such as the creation and restoration of fluvial wetlands, which can remove both legacy and new nitrogen, however, are cost-effective.},
	keywords={agriculture},
  year={2022}
}

Nitrogen pollution of waterways is a large global problem, especially in regions with intensive cropland agriculture such as the Mississippi River Basin that drains 40% of the continental United States. In contrast to prior studies, which mostly apply agronomic and hydrologic models, we collect detailed data from water quality monitors and use panel data econometric methods to estimate how land use affects nitrogen pollution. We find a strong positive effect of corn acreage on nitrogen concentration in nearby streams and rivers that is an order of magnitude smaller than those implied by the agronomic and hydrologic models. Our findings are consistent with a new line of research documenting accumulation of large amounts of nitrogen in subsurface soil and groundwater over several decades; this is excess nitrogen that was applied to fields but has yet to appear in waterways. This legacy nitrogen will eventually leach into streams and rivers exacerbating further nutrient pollution. In the presence of large amounts of legacy nitrogen, land retirement and other on-farm mitigation policies are uneconomic. Downstream off-farm practices, such as the creation and restoration of fluvial wetlands, which can remove both legacy and new nitrogen, however, are cost-effective.

@article{metaxogolou2022waterclimate,
  title={Nutrient Pollution and U.S. Agriculture: Causal Effects, Integrated Assessment, and Implications of Climate Change},
  author={Metaxogolou, Konstantinos and Smith, Aaron},
	url={https://files.asmith.ucdavis.edu/water_draft_climate.pdf},
	abstract={We study the relationship between water nutrient pollution and U.S. agriculture using data between the early 1970s and late 2010s. We estimate a positive causal effect of corn acreage on nitrogen concentration in the country’s water bodies using alternative empirical approaches. We find that a 10\% increase in corn acreage causes an increase in nitrogen concentration in water by at least 1\% and show that the magnitude of the acreage effect increases with precipitation but not with extreme temperature. Based on the average streamflow of the Mississippi River at the Gulf of Mexico during this period and damages of about 16 dollars per kilogram of nitrogen, this 1\% increase in average nitrogen concentration implies an annual external cost of 800 million dollars. We also report the results of additional integrated-assessment type of exercises aimed to inform policy makers, and we use recent climate models to project the implications of climate change on the magnitude of the estimated effects. We estimate that climate change will not materially change the relationship between corn acreage and nitrogen concentration in waterways.},
	keywords={agriculture},
  year={2022}
}

We study the relationship between water nutrient pollution and U.S. agriculture using data between the early 1970s and late 2010s. We estimate a positive causal effect of corn acreage on nitrogen concentration in the country’s water bodies using alternative empirical approaches. We find that a 10% increase in corn acreage causes an increase in nitrogen concentration in water by at least 1% and show that the magnitude of the acreage effect increases with precipitation but not with extreme temperature. Based on the average streamflow of the Mississippi River at the Gulf of Mexico during this period and damages of about 16 dollars per kilogram of nitrogen, this 1% increase in average nitrogen concentration implies an annual external cost of 800 million dollars. We also report the results of additional integrated-assessment type of exercises aimed to inform policy makers, and we use recent climate models to project the implications of climate change on the magnitude of the estimated effects. We estimate that climate change will not materially change the relationship between corn acreage and nitrogen concentration in waterways.

@article{bushnell2023lcfs,
  title={Forecasting Credit Supply Demand Balance for the Low-Carbon Fuel Standard Program},
  author={Bushnell, James and Lade, Gabriel and Smith, Aaron and Witcover, Julie and Xiao, Wuzheqian},
	url={https://files.asmith.ucdavis.edu/LCFS_report_2023_Final_Aug.pdf},
	abstract={
	
	In this report, we present our projections for the expected supply of and demand for Low Carbon Fuel Standard (LCFS credits) through 2030, as well as through 2035, based on potential changes to program stringency.  Our main approach is to apply time-series forecasting methods to project the expected demand for transportation fuels and combine that with the expected evolution of fuel prices and carbon intensities as well as complementary policies' impact on the fuel mix. Our results imply that the program can accommodate a relatively aggressive target of a 43\% reduction by 2035, but only if everything breaks right and many best-case outcomes arise toward the middle of the next decade.  By contrast, if ZEV penetration falls well below targets, the program could reach cumulative deficits of 60 to 100 MMT by 2035.  Our median forecast of our baseline scenario, targeting 30\% carbon intensity reduction by 2030 and 43\% by 2035, forecasts a small but significant cumulative deficit by 2035.},
	keywords={energy},
  year={2023}
}

In this report, we present our projections for the expected supply of and demand for Low Carbon Fuel Standard (LCFS credits) through 2030, as well as through 2035, based on potential changes to program stringency. Our main approach is to apply time-series forecasting methods to project the expected demand for transportation fuels and combine that with the expected evolution of fuel prices and carbon intensities as well as complementary policies' impact on the fuel mix. Our results imply that the program can accommodate a relatively aggressive target of a 43% reduction by 2035, but only if everything breaks right and many best-case outcomes arise toward the middle of the next decade. By contrast, if ZEV penetration falls well below targets, the program could reach cumulative deficits of 60 to 100 MMT by 2035. Our median forecast of our baseline scenario, targeting 30% carbon intensity reduction by 2030 and 43% by 2035, forecasts a small but significant cumulative deficit by 2035.

@article{novan2023ecobee,
  title={Do Time-of-Use Prices Deliver Energy Savings at the Right Time?},
  author={Fu, Zheng and Novan, Kevin and Smith, Aaron},
	url={https://files.asmith.ucdavis.edu/tou_ecobee_paper.pdf},
	abstract={Time-of-use(TOU) electricity prices are increasingly being adopted to reduce consumption during the higher marginal cost afternoon hours.There is ample evidence that TOU rates reduce average consumption during the peak price hours of the day,but it is unknown how these energy savings are distributed across days.Using a unique dataset from households with smart thermostats, we find that adopting TOU rates causes large decreases in peak period AC usage, resulting in energy savings that are concentrated on the hottest, highest demand days when the benefits of conservation are the greatest.},
	keywords={energy},
  year={2023}
}

Time-of-use(TOU) electricity prices are increasingly being adopted to reduce consumption during the higher marginal cost afternoon hours.There is ample evidence that TOU rates reduce average consumption during the peak price hours of the day,but it is unknown how these energy savings are distributed across days.Using a unique dataset from households with smart thermostats, we find that adopting TOU rates causes large decreases in peak period AC usage, resulting in energy savings that are concentrated on the hottest, highest demand days when the benefits of conservation are the greatest.

@article{mazzone2022passthrough,
  title={Pass-Through of Alternative Fuel Policy Incentives: Evidence from Diesel and Biodiesel Markets, the U.S. Renewable Fuel Standard, and Low Carbon Fuel Standards in California and Oregon},
  author={Mazzone, Daniel and Smith, Aaron and Witcover, Julie},
	url={https://files.asmith.ucdavis.edu/NCST_Pass_Through.pdf},
	abstract={Biodiesel and hydrotreated renewable diesel (RD)—or collectively biomass-based diesel (BBD)—have become integral components of compliance with policies aiming to reduce U.S. transportation sector greenhouse gas emissions. Such policies include the U.S. Renewable Fuel Standard (RFS), California’s Low Carbon Fuel Standard (LCFS), and Oregon’s Clean Fuel Program (CFP). These policies, along with a federal Blender’s BBD Tax Credit (BTC), provide financial incentives for BBD. In this white paper, we study pass-through of implicit taxes and subsidies, introduced by federal and state policies, to a variety of diesel and soy biodiesel fuel prices in the context of the U.S. diesel sector, focusing on fossil diesel and soy biodiesel. We apply time series methods techniques to estimate how a variety of diesel fuel price spreads across the country and in California and Oregon responds to changes in the implicit taxes placed on petroleum diesel and the implicit subsidies awarded to biodiesel. The results presented in this paper point to some inefficiencies in the RFS, LCFS, and CFP. The primary contribution of this paper was providing the first set of estimates of pass-through of LCFS implicit taxes and subsidies, and doing so for the diesel sector, a critical player in LCFS compliance.},
	keywords={energy},
  year={2022}
}

Biodiesel and hydrotreated renewable diesel (RD)—or collectively biomass-based diesel (BBD)—have become integral components of compliance with policies aiming to reduce U.S. transportation sector greenhouse gas emissions. Such policies include the U.S. Renewable Fuel Standard (RFS), California’s Low Carbon Fuel Standard (LCFS), and Oregon’s Clean Fuel Program (CFP). These policies, along with a federal Blender’s BBD Tax Credit (BTC), provide financial incentives for BBD. In this white paper, we study pass-through of implicit taxes and subsidies, introduced by federal and state policies, to a variety of diesel and soy biodiesel fuel prices in the context of the U.S. diesel sector, focusing on fossil diesel and soy biodiesel. We apply time series methods techniques to estimate how a variety of diesel fuel price spreads across the country and in California and Oregon responds to changes in the implicit taxes placed on petroleum diesel and the implicit subsidies awarded to biodiesel. The results presented in this paper point to some inefficiencies in the RFS, LCFS, and CFP. The primary contribution of this paper was providing the first set of estimates of pass-through of LCFS implicit taxes and subsidies, and doing so for the diesel sector, a critical player in LCFS compliance.

@article{bushnell2019uncertainty,
  title={Uncertainty, Innovation, and Infrastructure Credits: Outlook for the Low Carbon Fuel Standard Through 2030},
  author={Bushnell, James and Mazzone, Daniel and Smith, Aaron and Witcover, Julie},
	keywords={energy},
	url={https://www.ucits.org/research-project/using-low-carbon-fuel-standard-credits-to-support-low-carbon-fuel-infrastructure-policy-design-issues-and-impacts/},
	abstract={California's low carbon fuel standard (LCFS) specifies that the state’s transportation fuel supply achieve a 20\% reduction in carbon intensity (CI) below 2011 levels by 2030. Reaching the standard will require substantive changes in the fuel mix, but the specifics and the cost of these changes are uncertain. We assess if and how California is likely to achieve the standard, and the likely impact of infrastructure credits on this compliance outlook. We begin by projecting a distribution of fuel and vehicle miles demand under business-as-usual economic and policy variation and transform those projections into a distribution of LCFS net deficits for the entire period from 2019 through 2030. We then construct a variety of scenarios characterizing LCFS credit supply that consider different assumptions regarding input markets, technological adoption over the compliance period, and the efficacy of complementary policies. In our baseline scenario for credit generation, LCFS compliance would require that between 60% and 80% of the diesel pool be produced from biomass. Our baseline projections have the number of electric vehicles reaching 1.3 million by 2030, but if the number of electric vehicles reaches Governor Jerry Brown’s goal of 5 million by 2030, then LCFS compliance would require substantially less biomass-based diesel. Outside of rapid zero emission vehicle penetration, compliance in 2030 with the $200 credit price may be much more difficult. New mechanisms to allow firms to generate credits by building electric vehicle charging stations or hydrogen fueling stations have minor implications for overall compliance because the total quantity of infrastructure credits is restricted to be relatively small.},
  year={2019}
}

California's low carbon fuel standard (LCFS) specifies that the state’s transportation fuel supply achieve a 20% reduction in carbon intensity (CI) below 2011 levels by 2030. Reaching the standard will require substantive changes in the fuel mix, but the specifics and the cost of these changes are uncertain. We assess if and how California is likely to achieve the standard, and the likely impact of infrastructure credits on this compliance outlook. We begin by projecting a distribution of fuel and vehicle miles demand under business-as-usual economic and policy variation and transform those projections into a distribution of LCFS net deficits for the entire period from 2019 through 2030. We then construct a variety of scenarios characterizing LCFS credit supply that consider different assumptions regarding input markets, technological adoption over the compliance period, and the efficacy of complementary policies. In our baseline scenario for credit generation, LCFS compliance would require that between 60% and 80% of the diesel pool be produced from biomass. Our baseline projections have the number of electric vehicles reaching 1.3 million by 2030, but if the number of electric vehicles reaches Governor Jerry Brown’s goal of 5 million by 2030, then LCFS compliance would require substantially less biomass-based diesel. Outside of rapid zero emission vehicle penetration, compliance in 2030 with the $200 credit price may be much more difficult. New mechanisms to allow firms to generate credits by building electric vehicle charging stations or hydrogen fueling stations have minor implications for overall compliance because the total quantity of infrastructure credits is restricted to be relatively small.

@article{smith2018effects,
  title={Effects of the Renewable Fuel Standard on Corn, Soybean and Wheat Prices},
  author={Smith, Aaron},
	url={https://www.dropbox.com/s/wubrrij4b8mav1v/Smith%20-%20Effect%20of%20RFS%20on%20Prices_Latest.pdf?dl=1},
	abstract={The Renewable Fuel Standard (RFS2) became law in 2007. It dictates the minimum volume of biofuels such as ethanol and biodiesel that must be used each year for transportation fuel. In a recently published study, Carter, Rausser and Smith (2017) use a new econometric model to estimate the effects of the RFS on the corn market. They estimate that the RFS2 raised corn prices by about 30. This report summarizes their study and extends it to the soybean and wheat markets. I find that the RFS2 increased soybean and wheat prices by about 20\%.},
	keywords={energy},
  year={2018}
}

The Renewable Fuel Standard (RFS2) became law in 2007. It dictates the minimum volume of biofuels such as ethanol and biodiesel that must be used each year for transportation fuel. In a recently published study, Carter, Rausser and Smith (2017) use a new econometric model to estimate the effects of the RFS on the corn market. They estimate that the RFS2 raised corn prices by about 30. This report summarizes their study and extends it to the soybean and wheat markets. I find that the RFS2 increased soybean and wheat prices by about 20%.

@article{pouliot2017rin,
  title={RIN Pass-Through at Gasoline Terminals},
  author={Pouliot, Sebastien and Smith, Aaron and Stock, James H},
	url={https://www.dropbox.com/s/52yzs17hksxe0z9/Pass-through_Latest.pdf?dl=1},
	abstract={Wholesale suppliers at fuel terminals blend gasoline with ethanol to create finished gasoline. Under the US Renewable Fuel Standard (RFS), this blending activity is subsidized through a renewable fuel credit, known as a RIN. We estimate whether these suppliers, known as rack sellers, pass through the value of RINS. We find complete pass through in some locations and settings and not others. We argue that the incomplete pass-through we find stems from lack of salience about how the subsidy affects rack margins. If rack sellers have price-setting power in the RIN market, which is plausible, then the incomplete pass through we find creates an incentive for them to drive up RIN prices thereby raising compliance costs.},
	keywords={energy},
  year={2017}
}

Wholesale suppliers at fuel terminals blend gasoline with ethanol to create finished gasoline. Under the US Renewable Fuel Standard (RFS), this blending activity is subsidized through a renewable fuel credit, known as a RIN. We estimate whether these suppliers, known as rack sellers, pass through the value of RINS. We find complete pass through in some locations and settings and not others. We argue that the incomplete pass-through we find stems from lack of salience about how the subsidy affects rack margins. If rack sellers have price-setting power in the RIN market, which is plausible, then the incomplete pass through we find creates an incentive for them to drive up RIN prices thereby raising compliance costs.