Publications

This paper studies the response of agricultural production to rural labor loss during the process of urbanization. Using household microdata from India and exogenous variation in migration induced by urban income shocks interacted with distance to cities, we document sharp declines in crop production among migrant-sending households residing near cities. Households with migration opportunities do not substitute agricultural labour with capital, nor do they adopt new agricultural machinery. Instead, they divest from agriculture altogether and cultivate less land. We use a two-sector general equilibrium model with crop and land markets to trace the ensuing spatial reorganization of agriculture. Other non-migrant village residents expand farming (land market channel) and farmers in more remote villages with fewer migration opportunities adopt yield-enhancing technologies and produce more crops (crop market channel). Counterfactual simulations show that over half of the aggregate food production losses driven by urbanization is mitigated by these spillovers. This leads to a spatial reorganization in which food production moves away from urban areas and towards remote areas with low emigration.

Multiple price lists are a convenient tool to elicit willingness to pay (WTP) in surveys and experiments, but choice patterns such as “multiple switching” and “never switching” indicate high error rates. Existing measurement approaches often do not provide accurate standard errors and cannot correct for bias due to framing and order effects. We propose to combine a randomization approach with a random-effects latent utility model to detect bias and account for error. Data from a choice experiment in South Africa shows that significant order effects exist which, if uncorrected, would lead to distorted conclusions about subjects’ preferences. We provide templates to create a multiple price list survey instrument in SurveyCTO and analyze the resulting data using our proposed methods.

Tropical deforestation continues at alarming rates with profound impacts on ecosystems, climate, and livelihoods, prompting renewed commitments to halt its continuation. Although it is well established that agriculture is a dominant driver of deforestation, rates and mechanisms remain disputed and often lack a clear evidence base. We synthesize the best available pantropical evidence to provide clarity on how agriculture drives deforestation. Although most (90 to 99%) deforestation across the tropics 2011 to 2015 was driven by agriculture, only 45 to 65% of deforested land became productive agriculture within a few years. Therefore, ending deforestation likely requires combining measures to create deforestation-free supply chains with landscape governance interventions. We highlight key remaining evidence gaps including deforestation trends, commodity-specific land-use dynamics, and data from tropical dry forests and forests across Africa.

Ecological interactions are not uniform across time and can vary with environmental conditions. Yet, interactions among species are often measured with short-term controlled experiments whose outcomes can depend greatly on the particular environmental conditions under which they are performed. As an alternative, we use empirical dynamic modeling to estimate species interactions across a wide range of environmental conditions directly from existing long-term monitoring data. In our case study from a southern California kelp forest, we test whether interactions between multiple kelp and sea urchin species can be reliably reconstructed from time-series data and whether those interactions vary predictably in strength and direction across observed fluctuations in temperature, disturbance, and low-frequency oceanographic regimes. We show that environmental context greatly alters the strength and direction of species interactions. In particular, the state of the North Pacific Gyre Oscillation seems to drive the competitive balance between kelp species, asserting bottom-up control on kelp ecosystem dynamics. We show the importance of specifically studying variation in interaction strength, rather than mean interaction outcomes, when trying to understand the dynamics of complex ecosystems. The significant context dependency in species interactions found in this study argues for a greater utilization of long-term data and empirical dynamic modeling in studies of the dynamics of other ecosystems.

Climate change is altering the productivity of marine fisheries and challenging the effectiveness of historical fisheries management. Harvest control rules, which describe the process for determining catch limits in fisheries, represent one pathway for promoting climate resilience.  In the United States, flexibility in how regional management councils specify harvest control rules has spawned diverse approaches for reducing catch limits to precautionarily buffer against scientific and management uncertainty, some of which may be more or less resilient to climate change. Here, we synthesize the control rules used to manage all 507 U.S. federally-managed fish stocks and stock complexes. We classified these rules into seven typologies: (1) catch-based; (2) constant catch; (3) constant escapement; (4) constant F; (5) stepped F; (6) ramped F, and (7) both stepped and ramped F. We also recorded whether the control rules included a biomass limit (“cutoff”) value or were environmentally-linked as well as the type and size of the buffers used to protect against scientific and/or management uncertainty. Finally, we review the advantages and disadvantages of each typology for managing fisheries under climate change and provide seven recommendations for updating harvest control rules to improve the resilience of U.S. federally-managed fisheries to climate change.

This paper reviews and extends the recent empirical literature on the impact of climate change on mortality and adaptation in the United States. The analysis produces several new facts. First, the reductions in the impact of extreme heat on mortality risk previously documented up to 2004 have continued up to 2019, consistent with continued investments in health-protecting adaptations to high temperatures. The second part of the paper examines the private and external costs of electricity generation and consumption related to high temperatures, a commonly-used proxy for measuring the consumption of adaptation services. Extreme temperatures increase electricity demand in the residential sector (relative to moderate temperatures), but not in the commercial, industrial, and transportation end-use sectors. The additional electricity demand in response to high temperatures results in significant external costs due to the release of local and global pollutants caused by the combustion of fossil fuels in order to produce electricity. These external costs, documented for the first time in this paper, are one order of magnitude larger than the private cost of adaptation associated with electricity consumption.

Since its release in 2010, the US government’s social cost of carbon (SCC) has played a central role in climate policy both domestically and internationally. However, rapid progress in climate science and economics over the past decade means that the original SCC estimate is no longer based on the frontier of scientific knowledge. Specifically, extensive new research about the climate, the economy, and their relationship has altered our understanding of the magnitudes of the projected physical and economic impacts of climate change, as well as their heterogeneity across space and time. This article, which was written as the Biden presidential administration was actively rebuilding the US SCC, provides concrete recommendations on how to base the SCC on the most recent research advances and thus return it to the scientific frontier.

China’s power system is highly regulated and uses an “equal-share" dispatch approach. However, market mechanisms are being introduced to reduce generation costs and improve system reliability. Here, we quantify the climate and human health impacts brought about by this transition, modeling China’s power system operations under economic dispatch. We find that significant reductions in mortality related to air pollution (11%) and CO₂ emissions (3%) from the power sector can be attained by economic dispatch, relative to the equal-share approach, through more efficient coal-powered generation. Additional health and climate benefits can be achieved by incorporating emission externalities in electricity generation costs. However, the benefits of the transition to economic dispatch will be unevenly distributed across China and may lead to increased health damages in some regions. Our results show the potential of dispatch decision-making in electricity generation to mitigate negative impacts of power plant emissions with existing facilities in China.

The use of vessel tracking systems (VTS) on small-scale fishing vessels can provide data necessary for improved fisheries management. Nevertheless, the adoption of mandated VTS is still limited in small-scale fisheries given the hardship of establishing and enforcing vessel tracking regulations in this fishing sector. However, there is potential for incentivizing voluntary adoption of tracking programs in small-scale vessels. We surveyed small-scale fishers from Indonesia (n = 124) and Mexico (n = 87) to identify which attributes and conditions increase the likelihood of adoption of VTS programs. The survey included a choice experiment to elicit fishers' preferences over attributes of safety, privacy, and data ownership of hypothetical VTS programs along with a bidding game to gauge fishers' willingness to pay. Our results indicated that most fishers in Indonesia and Mexico are willing to pay for VTS programs. VTS programs that included a safety feature were preferred over those that did not. Fishers also indicated that they would prefer VTS programs that provide ownership of the data to fishers or the government instead of the industry or the public. Additionally, we found that individual fisher characteristics are strongly related to willingness to pay and are better predictors of fishers' willingness to pay than the program attributes. Understanding which VTS programs are more likely to be adopted, and by whom, is crucial to uncover the potential of this technology in informing small-scale fisheries management and supporting resource governance.

Clean cooking transitions can have profound public health, environmental and societal gains for 2.6 billion people in the Global South. We use data from the largest household energy survey (n= 7,389) in Ghana to provide novel insights. One, regression analysis with thirteen commonly cited socio-economic and demographic predictors indicates that these factors have remarkably different levels of influence at different stages of the transition process. We propose a stage-based intervention strategy and customer targeting approach that could be a paradigm shift in how clean cooking interventions are rolled out. Two, we identify factors that are associated with exclusive use of LPG using a statistically powered sample of exclusive LPG users (n= 693). We find that everything else being equal, increases in wealth, and residing in an urban location are not associated with a transition from primary to exclusive LPG use.

The magnitude of subsidies provided to the fishing sector by governments worldwide is immense—an estimated $35.4 billion USD per year. The majority of these subsidies may be impeding efforts to sustainably manage fisheries by incentivizing overfishing and overcapacity. Recognizing the threat these subsidies pose, the World Trade Organization has set a goal of reaching an agreement that would end fisheries subsidies that contribute to overcapacity, overfishing, and illegal fishing. However, negotiations have been hampered by uncertainty around the likely effects of reforming these subsidies. Here we present a novel method for translating a bioeconomic model into an interactive online decision support tool that draws upon real-world data on fisheries subsidies and industrial fishing activity so users can directly compare the relative ambition levels of different subsidy reform options.

As the human population and demand for food grow¹, the ocean will be called on to provide increasing amounts of seafood. Although fisheries reforms and advances in offshore aquaculture (hereafter ‘mariculture’) could increase production², the true future of seafood depends on human responses to climate change³. Here we investigated whether coordinated reforms in fisheries and mariculture could increase seafood production per capita under climate change. We find that climate-adaptive fisheries reforms will be necessary but insufficient to maintain global seafood production per capita, even with aggressive reductions in greenhouse-gas emissions. However, the potential for sustainable mariculture to increase seafood per capita is vast and could increase seafood production per capita under all but the most severe emissions scenario. These increases are contingent on fisheries reforms, continued advances in feed technology and the establishment of effective mariculture governance and best practices. Furthermore, dramatically curbing emissions is essential for reducing inequities, increasing reform efficacy and mitigating risks unaccounted for in our analysis. Although climate change will challenge the ocean’s ability to meet growing food demands, the ocean could produce more food than it does currently through swift and ambitious action to reduce emissions, reform capture fisheries and expand sustainable mariculture operations.

The spatial distribution of many public lands in the western U.S. is an artifact of 19th century land-disposal policies. While this legacy is sometimes an impediment to conservation, it may also provide novel opportunities to spatially reorganize public conservation lands within realistic budget constraints. Here we seek to understand the conservation potential of strategically rearranging inaccessible (“stranded”) public land in Montana, US. We use conservation reserve network design and consider coarse- and fine-filter conservation features—land cover types and predicted habitat for 12 umbrella species, respectively—and incorporate habitat connectivity corridors into one reserve design scenario. All conservation reserve network designs are constrained by a budget equal to the current value of stranded public land parcels and seek to meet or exceed the extent of conservation currently provided by stranded parcels with respect to land cover type and predicted species habitat. We find that each conservation reserve simulation expands the total protected area in Montana within the realistic budget constraint. Two maximum coverage scenarios, which exhaust the budget, result in reserve designs that substantially exceed coarse- and fine-filter conservation targets. All reserve designs provide landscape connectivity benefits. Our results illustrate notable and practical opportunities to develop conservation reserve networks in the western US that account for landscape connectivity and that benefit both private landowners and biodiversity conservation efforts through land trades and acquisitions.

Using 40 countries’ subnational data, we estimate age-specific mortality-temperature relationships and extrapolate them to countries without data today and into a future with climate change. We uncover a U-shaped relationship where extre6me cold and hot temperatures increase mortality rates, especially for the elderly. Critically, this relationship is flattened by higher incomes and adaptation to local climate. Using a revealed-preference approach to recover unobserved adaptation costs, we estimate that the mean global increase in mortality risk due to climate change, accounting for adaptation benefits and costs, is valued at roughly 3.2% of global GDP in 2100 under a high-emissions scenario. Notably, today’s cold locations are projected to benefit, while today’s poor and hot locations have large projected damages. Finally, our central estimates indicate that the release of an additional ton of CO₂ today will cause mortality-related damages of $36.6 under a high-emissions scenario, with an interquartile range accounting for both econometric and climate uncertainty of [−$7.8, $73.0]. These empirically grounded estimates exceed the previous literature’s estimates by an order of magnitude.

Costs of fighting wildfires have increased substantially over the past several decades. Yet surprisingly little is known about the effectiveness of wildfire suppression or how wildfire incident managers prioritize resources threatened within a wildfire incident. We investigate the determinants of wildfire suppression effort using a novel empirical strategy comparing over 1,400 historical fire perimeters to the spatial distribution of assets at risk. We find that fires are more likely to stop spreading as they approach homes, particularly when homes are of greater value. This effect persists after controlling for physical factors (fuels, landscape, and weather) using a state-of-the-art wildfire simulation tool. As well, the probability that spread will be halted is affected by characteristics of homes 1–2 kilometers beyond a fire’s edge. Overall, we find that suppression efforts can substantively affect wildfire outcomes but that some groups may benefit more from wildfire management than others.

Credit markets and property rights are fundamental for modern economies, but they also have implications for the commons. Using a dynamic model of competitive resource extraction, we show that improving property right security unambiguously increases conservation incentives, but the effect of credit markets on resource extraction effort hinges on the security of property rights. We test these predictions using data on global fisheries, credit markets, and the largest-ever marine property rights assignment. We find that property right security reduces resource extraction, while credit market development increases resource extraction under insecure property rights but reduces resource extraction under secure property rights.

Fuel break effectiveness in wildland-urban interface (WUI) is not well understood during downslope wind-driven fires even though various fuel treatments are conducted across the western United States. The aim of this paper is to examine the efficacy of WUI fuel breaks under the influence of strong winds and dry fuels, using the 2018 Camp Fire as a case study. The operational fire growth model Prometheus was used to show: (1) downstream impacts of 200 m and 400 m wide WUI fuel breaks on fire behavior and evacuation time gain; (2) how the downstream fire behavior was affected by the width and fuel conditions of the WUI fuel breaks; and (3) the impacts of background wind speeds on the efficacy of WUI fuel breaks. Our results indicate that WUI fuel breaks may slow wildfire spread rates by dispersing the primary advancing fire front into multiple fronts of lower intensity on the downstream edge of the fuel break. However, fuel break width mattered. We found that the lateral fire spread and burned area were reduced downstream of the 400 m wide WUI fuel break more effectively than the 200 m fuel break. Further sensitivity tests showed that wind speed at the time of ignition influenced fire behavior and efficacy of management interventions.

Natural resources such as carbon, water, and fish are increasingly managed with markets that require an initial allocation of property rights. In practice these rights are typically grandfathered based on historical use, but rights could be allocated any number of ways. Taking the perspective of a currently unregulated firm, we ask how the anticipation of a future market affects extraction incentives, environmental quality, and welfare prior to the implementation of the market. We show that this anticipation has first-order welfare implications, seemingly contradicting the widely held belief that the allocation of rights has no aggregate welfare consequences. The most egregious case involves anticipation of a traditional grandfathering rule, which induces a race for allocation before the market goes into effect, causing over-extraction or over-emissions, even relative to the completely unregulated baseline. We derive an alternative allocation rule called "Reverse-Grandfathering" that still provides a free allocation of rights but reverses the marginal incentive to emit or extract. We show that this new approach, which relies on incentives due to anticipation, can replicate welfare-maximizing firm behavior, even in the complete absence of regulation. To illustrate the potential magnitude of anticipation effects, we develop and parameterize a structural model of a hypothetical market among nearly 5,000 large fishing firms on the high seas. Relative to traditional grandfathering and auctioning of rights, ReverseGrandfathering substantially increases natural resource stocks and welfare.

The adoption of sustainable alternative foods could potentially reduce the environmental burden of human food production if it can reduce demand for products with higher environmental impact. However, there is little empirical evidence for how frequent food consumption declines are when alternative foods are introduced, limiting our knowledge of the potential for such introductions to drive food system transformations. Using 53 years of food supply data for 99 crop, livestock, and seafood commodities in 159 countries, we use regression analyses on 12 883 time series—each representing a single country-commodity pair—to detect sustained declines in apparent national food consumption, as well as corresponding consumption increases of other food commodities. First, we show that sustained declines in the consumption of any food item are rare, occurring in 9.6% of time series. Where declines are present, they most frequently occur in traditional plant-based staples, e.g. starchy roots, and are larger compared to animal-source foods, particularly in low- and middle-income countries where much of the future increase in food demand is expected to occur. Second, although declines were rare, we found national production rather than trade was identified as the most common proximate driver of declines in consumption, suggesting that shifts in diets have the potential to translate into reduced environmental impacts from food production. Third, we found consumption increases were nearly twice as common as declines, but only 8% of declines (from within 4% of total time series) occurred parallel to incline events within the same food group, suggesting limited interchangeability. An examination of case studies suggests that alternative foods can facilitate food system transitions, but strong relative disadvantages for existing foods across aspects of technology, markets, policy and culture need to exist in parallel to support for alternative foods across the same factors. Where existing foods are already produced in highly efficient systems, a lack of systematic disadvantage may provide a barrier to alternative foods driving change.