Projects Funded for 2019-2020

A Century of California Agricultural Mechanization, 1860-1960

  • Alan Olmstead
  • Paul Rhode

Unpacking Residential Water Consumption and the Impacts of Nudges: A Machine Learning Application

  • Mehdi Nemati


Specific Objectives of the Project:

  • Disaggregate residential water consumption to indoor and outdoor usage using machine learning methods.
  • Estimate effect of HWURs on indoor and outdoor water consumption (obtained in the first objective).
  • Estimate the impact of HWURs on peak hour and day water consumption.

Project Progress Report:
Using around 600 million hourly water use data and machine learning methods, including Random Forests (RFs), Artificial Neural Networks (ANNs), and Support Vector Regression (SVR) we were able to disaggregate total water use to indoor and outdoor usage. The preliminary results indicate that 60% of total water use is related to outdoor activities, mainly lawn irrigation, and happens between 10 pm and 4 am. The pick hour consumption is between 12 am and 3 am.
For the two other objectives, we merged the disaggregated data with census demographics and weather information such as temperature and precipitation. In addition, we observe Home Water Use Repots message content and timing for the enrolled households. Currently, we are in process of generating and processing the models for the second and third objective.

The Tradeoff Facing Agricultural Workers Between Wages and Health Care and other Benefits

  • Jeffrey Perloff


Specific Objectives of the Project:
We investigated the tradeoff facing hired, seasonal agricultural workers between wages and various benefits, particularly health care insurance.

Project Report/Summary of Results:
The Affordable Care Act (ACA) made health insurance more available to low-wage people, such as documented hired-seasonal-agricultural workers. Were workers who gained government health insurance more likely to take jobs that offered high wages and few benefits rather than jobs with lower wages that offered more benefits? Based on data from the National Agricultural Worker Survey from 2010 through 2016, the on-the-job benefits of these workers did not change significantly after the ACA went into effect. Incentive benefits, season-ending benefits, and holiday benefits did not change at all. Agricultural jobs provided health insurance at the same rate as prior to ACA. However, documented workers, particularly those with pre-existing medical conditions, were much 11.4% more likely to have government health insurance and 5.6% less likely to rely on employer insurance.

The Political Economy of Implementing California’s Sustainable Groundwater Management Act (SGMA)

  • Ellen Bruno


Specific Objectives of the Project:
(a) Construct a database on how the 298 agencies registered at present to manage basins under SGMA are (i) structured legally, (ii) governed, and (iii) planning to implement the SGMA mandates;
(b) Study differences in (iii) as a function of (i) and (ii) and other characteristics of the underlying groundwater resources, agricultural products being produced, and urban/rural interfaces; and
(c) Provide guidance to groundwater agencies, California Department of Water Resources (DWR), and other policy makers regarding implementing SGMA based on results adduced from (a) and (b).

Project Report/Summary of Results:
We are assembling a database on groundwater agencies operating under the aegis of SGMA and on the plans they are submitting to the CA Department of Water Resources to achieve sustainability of the groundwater basins and sub-basins they oversee. We are especially interested in the composition of governing boards and technical advisory committees that provide input to the boards and then linking board/committee characteristics to the essential features of the plans these agencies are formulating and submitting to the State.

The Impacts of Extreme Temperatures and Drought on Mental Health and Suicide in California's Agricultural Community

  • Kurt Schwabe

The Impacts of a Declining Farm Labor Supply on Farming in California

  • J. Edward Taylor


Specific Objectives of the Project: Objective

  1. To analyze how labor shortages are affecting the use of the H-2A visa program and farm labor contractors in California.
  2. To analyze how higher labor costs are affecting the crop mix, the use of labor-saving technologies, and cultivation practices in California.
  3. To analyze the extent to which reductions in the farm labor supply are affecting the production of fruit and vegetable crops in California.

Project Report/Summary of Results:
The funds provided through this grant enabled us to continue processing and analyzing the data we collected from a 2019 survey that we conducted in collaboration with the California Farm Bureau Federation. Additional analysis of these data revealed that farmers have found it increasingly difficult to gain access to an adequate supply of farm workers between 2014 and 2018. Fifty-eight percent of the 1000+ farmers we surveyed reported that they were unable to hire enough workers at some point between 2014 and 2018, and a higher share of those reporting labor shortages between that time span said that they experienced shortages in 2017 and 2018. In response to labor-availability problems, farmers reported making a variety of changes to their usual production practices. First of all, the vast majority of farmers reported having to raise wages to attract and retain workers. Between 2014 and 2018, the share of farmers reporting that they had to raise wages to attract workers increased from 31% to 79%. Second, farmers report becoming increasingly reliant upon farm labor contractors (FLC) and the H-2A visa program. The most common reason for using an FLC was to make sure they had enough workers, while about a quarter
of respondents indicated that they used them to reduce the administrative burden associated with hiring farm workers. About 5% of farmers indicated that they had switched acreage out of labor-intensive fruit and vegetable crop production into mechanically-harvested crops. Of those who indicated that they had switched some acreage out of labor-intensive crop production into non-labor-intensive crops, the majority switched into the production of tree nuts, revealing evidence that is consistent with some media reports. About one-third of the farmers indicated that they had to change one (or more) of their usual cultivation practices at some point between 2014 and 2018 either because there were not enough workers available or because of rising labor costs. The percentage of farmers who reported having to change cultivation practices increased by 18 percentage points between 2014 and 2018. Roughly twenty percent of the farmers indicated that they had started using a labor-saving technology for the first time between 2014 and 2018. The most common types of labor-saving technologies were mechanical harvesters for wine grapes and specialized tractor attachments. The main reason for adopting these technologies was rising labor costs; although, over half of those who adopted a labor-saving technology for the first time also said that farm worker availability played a role in the decision, too.

Additional research that was conducted under this grant included ongoing work with cooperating personnel member Diane Charlton, which led to a (forthcoming) publication in the journal Agricultural Economics (see publication section below). This work uses panel data from a nationally-representative survey of rural households in Mexico and finds that educational attainment among rural Mexicans, which has been stimulated by investments by the Mexican government, has led to a decline in the supply of farm workers. This decline in the supply of farm workers is driven by higher returns in non-farm sectors of the economy due to the acquisition of valuable human capital, which has opened up opportunities to engage in non-farm employment for rural Mexicans.

The Economics of Supply Chains with Application for Animal-free Meats: Impacts on the Economy and the Environment

  • David Zilberman


Specific Objectives of the Project:

  1. To expand a conceptual framework for a design of supply chains to include dynamic considerations and diffusion over space and time.
  2. To develop a conceptual framework to understand the alternative route that is employed by researchers to produce cultured meats.
  3. To develop a conceptual framework to assess the implications of different strategies on design of supply chains for production and distribution of the meat products and for procurement of feedstock.
  4. To assess the potential economic and environmental impact of alternative cultured meats on various sectors of agriculture, consumers, as well as the environment. This analysis will be conceptual.
  5. To consider how alternative policies may affect the evolution of the industry.
  6. To numerically provide orders of magnitude estimates of the impacts under alternative scenarios.

Project Report/Summary of Results:
Innovations in food science have led to the emergence of plant-based substitutes for animal meat products. Our analysis overviewed some of the emergent products and analyzed the economic conditions that lead to their growths. We argue that plant-based meat substitutes increase the input use efficiency of grains but the technology is in earlier stages and will benefit from learning by doing and upscaling. We expect that the use may be gradual and dependent upon the technological improvements and consumer preferences. These products have the potential to reduce greenhouse gases and the environmental side effects of agriculture. We developed basic formulas to assess the condition for their expansion and growth but further research is required to quantify their impacts.

Plant-based meat is only in its infancy. If consumers will accept it as a close substitute for meat, its seemingly lower input requirements, and GHG emissions contributions, it will change the structure of agribusiness, the economics of food and agriculture and rural regions. We argue that it will reduce the livestock sector significantly and reduce footprint and the environmental impacts agriculture. It will have a significant distribution effect reducing the wellbeing of animal agriculture. However, the changes will take time and we expect significant efforts to stop the technology. The use of biotechnology and creative culinary efforts may affect the quality and economic of plant-based meat.

Land Subsidence--The Forgotten Enigma of Groundwater (Over) Extraction: Implications to California

  • Ariel Dinar


Specific Objectives of the Project:
(1) The overall objective of this proposed research is to examine and quantify (also monetarily) the impact of various land subsidence (LS) effects in California in the short and long-run.
Specific objectives include:
(2) Catalogue the various locations of LS in California based on the severity of the land subsidence issues;
(3) Develop an analytical framework to evaluate the tradeoff between benefits from pumping groundwater for consumption in urban and irrigation activities and the social cost of doing so (including energy for pumping from deeper level, water quality degradation from intrusion of low-quality water, and damages from LS to infrastructure and from groundwater storage loss);
(3.1) Derive optimal rates of pumping of groundwater for combinations of aquifer geological formations and value of water in economic activities;
(3.2) Apply the analytical framework to several locations in California known to be affected by LS;
(4) Derive policy implications with relevance to SGMA (Sustainable Groundwater Management Act).

Project Report/Summary of Results:
Land subsidence (LS) is the settlement of the land surface triggered by human-induced and natural-driven processes, such as oxidation of organic soils, sub-surface water mining, or fluids extraction (oil, gas and groundwater). Land subsidence is a global problem, mostly studied and recognized, to different extents, in association with aquifer over-exploitation. LS occurrence around the world is most prominent in those aquifers composed of loose unconsolidated materials (e.g. sands, clays, silts, etc.) that are over pumped. It is assessed that LS inflicts significant damages on local communities and on the environment. As such, identifying the types of damages and quantifying them both in terms of the various physical impacts and their economic values, short- and long-term, would be an essential first step for preparing policies to address the problem.

Most studies on LS are indicative in the sense that they identify the driving process and measure the land subsidence amount and extent in a specific locality. Few are the works that assess the impacts of LS in terms of social, environmental and economic consequences.

In this project we developed two research directions (1) development of a regional model to explain the economics of optimal GW pumping in the presence of LS and (2) development of a quantitative method to assess the extent of LS and apply it to various aquifers.

Our findings suggest that optimal GW pumping regimes in the presence of LS should be more conservative than when LS is minimal or not absence. Damages to infrastructure and loss of storage capacity are major social costs that affect the optimal pumping regime and should be part of a regional policy to sustain the regional resources. The model was applied in three locations: Po Basin, Italy; Murcia, Spain; Chino Basin, California and demonstrated the value of preventive and responsive policies.

Findings from the second research direction, while still in progress, quantified, based on data from 119 locations globally, relationship between Extent of Land Subsidence and explanatory variables to suggest the impact of climatic, institutional, geological, and policy interventions on the extent of the impact of land subsidence damages measured by a vector of 10 damage aspects.

Impact of SGMA on Crop Mix in California

  • Bruce Babcock


This was year one of a two-year project

Specific Objectives of the Project:

  • Collect data on soils, crops, production costs, and groundwater sustainability plans in the San Joaquin Valley.
  • Develop a mathematical programming model to allow simulation of optimal crop mix within and between groundwater sustainability agency (GSA) boundaries under alternative scenarios regarding irrigation water availability.
  • Simulate the effects of decreased water availability on crops grown in the San Joaquin Valley’s GSA’s.

Project Report/Summary of Results:
This first year of the project consisted of compiling geo-referenced data on crop production (yields and acreage), crop profitability, and groundwater sustainability plans, that are required to calibrate a spatially explicit programming model of crop supply in the San Joaquin Valley. We have decided that the decision unit in the model will be determined by GSA boundaries as they coincide with each GSA’s groundwater sustainability plans. We hired a post-doctoral student, Dat Tran, to lead our modeling effort. He will join us from the University of Arkansas once UCR is again accessible to faculty and staff.

Guest Workers in California Agriculture

  • Philip Martin


Specific Objectives of the Project:
The average employment of hired workers in California agriculture was 425,000 in 2016, almost three times the 152,000 average employment in the state’s food manufacturing industry. Almost a million unique workers fill full-time equivalent jobs on California farms, a ratio of 2.2 workers per FTE job, and average employment is rising.

This project focuses on three issues of great importance to California agriculture. The first is immigration, which determines the supply of labor to California agriculture since 90 percent of the state’s farm workers were born abroad. The second is adjustments to fewer unauthorized newcomers, including the 4-S strategies, of satisfying current workers, stretching them with productivity enhancements, substituting machines for hand workers, and supplementing the current workforce with H-2A guest workers. The third issue analyzes the effects of state regulatory changes, including the minimum wage of $15 an hour and the requirement to pay overtime wages after eight hours a day or 40 a week in 2022.

The project supports several major activities, including research articles, shorter papers in ARE Update and the quarterly Rural Migration News as well as monthly blogs ( We host a major research and public conference each year that attracts over 120 participants; the conferences scheduled for March 19-20, 2020 was postponed due to the coronavirus. The results of the project are disseminated widely, including in the new edition of Giannini’s California Agriculture book and to the more than 1,000 subscribers of the Rural Migration newsletter and blogs. The project had numerous interactions with federal and state analysts, journalists, and others.

Project Report/Summary of Results:
Farm employment has been rising as more expensive land and water encourages a switch to high value fruits and vegetables. Average farm employment has been increasing by 10,000 a year, and the number of unique workers employed in agriculture has been expanding by 20,000 a year, so that in 2016 almost a million unique workers filled an average 425,000 farm jobs.

The hired workers on crop farms are aging (average 41 and approaching the average 42 of all US workers) and settling in one place with their families. Follow-the-crop migration has almost disappeared, and there are fewer unauthorized newcomers, making the current farm workforce less flexible. Farm employers are responding with 4-S strategies. Employers try to satisfy current workers to retain them longer and stretch them with mechanical aids that increase productivity by making farm work easier. The third strategy is substitution, replacing workers with machines, or switching crops, and the fourth is to supplement with H-2A guest workers, who have become the flexible newcomers to the farm workforce.

In the medium term, the two dominant strategies are substitution and supplement, a race between labor-saving technologies and guest worker admissions. Responses vary by commodity, and are influenced by policy decisions. For example, the raisin industry is likely to shrink faster as labor costs rise and some farmers mechanize while others switch to almonds. Strawberries are more likely to supplement with guest workers and use conveyor belts in the fields to stretch workers until there is a mechanization breakthrough. Imports are the wild card, and may play an increasing role in supplying some commodities to US consumers.

The project monitored the impacts of farm labor developments on the competitiveness of California agriculture, conducted research that was published in a variety of outlets, and made presentations to a dozen groups ranging from the National Council of Agricultural Employers to the Agricultural Personnel Management Association, plus talks in classes at UCD and elsewhere. In March-April 2020, the project generated several short papers on the coronavirus.

Farmworkers and Nonfarm Work: How Many Are Leaving and Why

  • Pierre Mérel


Specific Objectives of the Project:
The objectives of this research are to (1) quantify past adaptation to climate change in United States field crop production, (2) estimate the long-run consequences of climate change on this type of agriculture, and (3) assess the potential of one specific adaptation, double-cropping, to attenuate the potential losses resulting from climate change.

Project Report/Summary of Results:
We have developed a theoretical framework whereby agricultural production is related to both contemporaneous weather and long-run climate through simple quadratic functions. The framework implies a long-run response function to climate that is the outer envelope of short-run responses to weather conditional on climate. Applying this framework to a 66-year panel of yields and weather, we simultaneously estimate short- and long-run responses to climate for the United States (US) corn sector. We find evidence of significant climatic adaptation. In the case of temperature exposure (captured through growing degree days), traditional “myopic” panel methods that do not explicitly model climate adaptation nonetheless deliver estimates similar to those of our estimated long-run response. We formally show that this is due to the large cross-sectional variation in climate temperature relative to locational weather fluctuations. In contrast, for precipitation, which exhibits larger year-to-year variation relative to cross-sectional variation, models that do not account for climatic adaptation deliver estimates that are biased, but can be viewed as an average of the long- and short-run responses.

In complementary work, we focus on one specific adaptive action: double cropping. Although prior agronomic research suggests that climate change may expand the area suitable for double cropping in the US, there is relatively little empirical evidence of the relationship between climate and farmers’ decisions to double crop. We link high-resolution land cover data with detailed soil and climate data to explain farmers' propensity to double-crop soybeans with winter wheat in the Eastern United States. We find small and slightly negative effects of warming on double-cropped acreage. A fixed-effects panel model of county yields further indicates that yields of double-cropped soybeans are about 9.9% lower than those of single-cropped soybeans. Accounting for both of these effects, we conclude that double cropping is unlikely to offset negative impacts of climate change on US crop production.

Economics of Brettanomyces in California Wine Production

  • Julian Alston

Consumer Valuation of Aquaculture Attributes

  • Sofia Villas-Boas


Specific Objectives of the Project:
Gather data on consumer stated valuations for seafood and aquaculture attributes

Project Report/Summary of Results:
We have gathered a comprehensive data set on the geographic and time patterns of production of aquaculture in the United States and have started developing a survey instrument to producers and also an additional survey instrument to consumers in the production areas, as well as a representative sample of US consumers . We do not have a draft available yet of your data analysis and plan to have one in a year.

Best Management Practices to Mitigate Water Quality Impairments: What Are the Benefits and Costs?

  • Tina Saitone


Specific Objectives of the Project:
Nonpoint source pollution is the leading cause of water quality impairments in California. Many sources, including cattle grazing in or around streams, lakes, and wetlands, may contribute to the pollution of surface waters. Grazing best management practices (e.g., riparian fencing, off-stream water, etc.) have been shown to reduce fecal-based microbial pollutants and improve surface water quality. Objectives of this project are threefold: i) estimate the biophysical reductions in fecal indicator bacteria over time, ii) estimate the costs associated with grazing best management practices, and iii) compare these costs to biophysical results in the literature on efficacy to estimate benefit/cost of practice implementation.

Project Report/Summary of Results:
Coastal areas support multiple important resource uses including recreation, aquaculture, and agriculture. Unmanaged cattle access to stream corridors in grazed coastal watersheds can contaminate surface waters with fecal-derived microbial pollutants, posing risk to human health via activities such as swimming and shellfish consumption. Improved managerial control of cattle access to streams through implementation of grazing best management practices (BMPs) is a critical step in mitigating waterborne microbial pollution in grazed watersheds. This work reports trend analysis of a 19-year dataset to assess longterm microbial water quality responses resulting from a program to implement 40 grazing BMPs within the Olema Creek Watershed, a primary tributary to Tomales Bay, USA.

Stream corridor grazing BMPs implemented included: 1) Stream corridor fencing to eliminate/control cattle access, 2) hardened stream crossings for cattle movements across stream corridors, and 3) off stream drinking water systems for cattle. We found a statistically significant reduction in fecal coliform concentrations following the initial period of BMP implementation, with overall mean reductions exceeding 95% (1.28 log10)—consistent with 1—2 log10 (90 – 99%) reductions reported in other studies. Our results demonstrate the importance of prioritization of pollutant sources at the watershed scale to target BMP implementation for rapid water quality improvements and return on investment. Our findings support investments in grazing BMP implementation as an important component of policies and strategies to protect public health in grazed coastal watersheds. In total, this suite of practices cost over $870,000 to implement. The remaining work on this project (in progress) uses spatial and temporal variation in practice implementation to determine the benefits and costs associated at the practice level.

An Optimal Tax Approach to Policy Problems in California Agriculture

  • James Sallee


Specific Objectives of the Project:
The aim of this project is to apply a particular set of economic tools to analyze policies aimed at mitigating externalities from agriculture, using data from California.

Project Report/Summary of Results:
The goal of this project is applying the tools of public finance to evaluate policies aimed at mitigating externalities from California agriculture. The research team studied several possible applications and settled on the use of digesters to mitigate methane emissions from dairies. The team assembled data on the cost and location of all digesters in the state and used those data to estimate mitigation costs per ton of emissions. These costs vary substantially due to economies of scale and agglomeration effects, because cost depends on the proximity of each dairy to existing natural gas infrastructure and other dairies.

Given this distribution of costs, we can characterize the efficiency and distributional consequences of different regulatory policies (e.g., digester mandates versus digester subsidies versus a renewable natural gas feed-in tariff versus a tax on emissions or dairy products). In addition, we have identified direct measures of methane emissions tied to individual dairies from remotely sensed data collected by NASA’s Jet Propulsion Laboratory that provide a check on our modeled mitigation potentials.