Solomon Hsiang directs the Global Policy Laboratory at Berkeley, where his team is integrating econometrics, spatial data science, and machine learning to answer questions that are central to rationally managing planetary resources--such as the economic value of the global climate, how the UN can fight wildlife poaching, the effectiveness of treaties governing the oceans, and whether satellites and AI can be combined to monitor the entire planet in real time.
Hsiang earned a BS in Earth, Atmospheric and Planetary Science and a BS in Urban Studies and Planning from the Massachusetts Institute of Technology, and he received a PhD in Sustainable Development from Columbia University. He was a Postdoctoral Fellow in Applied Econometrics at the National Bureau of Economic Research (NBER) and a Postdoctoral Fellow in Science, Technology and Environmental Policy at Princeton University.
Hsiang is currently the Chancellor's Professor of Public Policy at the University of California, Berkeley, a Co-Director at the Climate Impact Lab, Research Associate at the NBER, a National Geographic Explorer, and an Andrew Carnegie Fellow. Hsiang is currently the Lead Author of the Economics chapter for the Fifth National Climate Assessment. In 2020, he was awarded the President’s Medal by the Geological Society of America.
Contact
Office 2607 Hearst, Room 303
About
Areas of Expertise
- Agriculture
- Climate Change
- Environment
- International
- Coupled Natural and Human Systems
- Political Economy
- Development Economics
- Applied Econometrics
Curriculum Vitae
Research
Working Papers
Valuing the Global Mortality Consequences of Climate Change Accounting for Adaptation Costs and Bene
Working Paper (July 2019)
We develop empirically-grounded estimates of willingness-to-pay to avoid excess mortality risks caused by climate change. Using 40 countries' subnational data, we estimate a mortality-temperature relationship that enables global extrapolation to countries without data and projection of its future evolution, accounting for adaptation benefits. Further, we develop a revealed preference approach to recover unobserved adaptation costs. We combine these components with 33 high-resolution climate simulations, which produces a right-skewed distribution of global WTP with a mean of $38.1 per tCO2 under a high emissions scenario. Projections generally indicate increased mortality in today's poor locations and higher adaptation expenditures in rich ones.
Accounting for Unobservable Heterogeneity in Cross Section Using Spatial First Differences
Working Paper (June 2019)
We develop a simple cross-sectional research design to identify causal effects that is robust to unobservable heterogeneity. When many observational units are dense in physical space, it may be sufficient to regress the “spatial first differences” (SFD) of the outcome on the treatment and omit all covariates. This approach is conceptually similar to first differencing approaches in timeseries or panel models, except the index for time is replaced with an index for locations in space. The SFD design identifies plausibly causal effects, even when no instruments are available, so long as local changes in the treatment and unobservable confounders are not systematically correlated between immediately adjacent neighbors. We demonstrate the SFD approach by recovering new cross-sectional estimates for the effects of time-invariant geographic factors, soil and climate, on long-run average crop productivities across US counties — relationships that are notoriously confounded by unobservables but crucial for guiding economic decisions, such as land management and climate policy.
Destructive Behavior, Judgement, and Economic Decision-Making Under Thermal Stress
Working Paper (April 2019)
Accumulating evidence indicates that environmental temperature substantially affects economic outcomes and violence, but the reasons for this linkage are not well understood. We systematically evaluate the effect of thermal stress on multiple dimensions of economic decisionmaking, judgment, and destructive behavior with 2,000 participants in Kenya and the US who were randomly assigned to different temperatures in a laboratory. We find that most dimensions of decision-making are unaffected by temperature. However, heat causes individuals to voluntarily destroy other participants’ assets, with more pronounced effects during a period of heightened political conflict in Kenya.
Spatial Correlation, Trade, and Inequality: Evidence from the Global Climate
Working Paper (January 2019)
This paper shows that greater global spatial correlation of productivities can increase crosscountry welfare dispersion by increasing the correlation between a country’s productivity and its gains from trade. We causally validate this general-equilibrium prediction using a global climatic phenomenon as a natural experiment. We find that gains from trade in cereals over the last halfcentury were larger for more productive countries and smaller for less productive countries when cereal productivity was more spatially correlated. Incorporating this general-equilibrium effect into a projection of climate-change impacts raises projected international inequality, with higher welfare losses across most of Africa.
The Marginal Product of Climate
Working Paper (November 2017)
We develop an empirical approach to value changes to a climate in terms of total market output given optimal factor allocations in general equilibrium. Our approach accounts for unobservable heterogeneity across locations as well as the costs and benefits of adaptation in climates of arbitrary dimension. Importantly, we demonstrate that the Envelope Theorem implies the marginal product of a long-run climate can be exactly identified using only idiosyncratic weather variation. We apply this method to the temperature climate of the modern United States and find that, despite evidence that populations adapt, the marginal product of temperature has remained unchanged during 1970-2010, with high temperatures having low net value. Integrating marginal products recovers a value function for temperature, describing the causal effect of non-marginal climate changes net of adaptive re-optimization. We use this value function to consider the influence of temperature in the current cross-section and a future climate change scenario.
Selected Publications
Strengthened scientific support for the Endangerment Finding for atmospheric greenhouse gases
Duffy, Field, Diffenbaugh, Doney, Dutton, Goodman, Heinzerling, Hsiang, Lobell, Mickley, Myers, Natali, Parmesan, Tierney, Williams, Science (2019): Vol. 363, Issue 6427
We assess scientific evidence that has emerged since the U.S. Environmental Protection Agency’s 2009 Endangerment Finding for six well-mixed greenhouse gases and find that this new evidence lends increased support to the conclusion that these gases pose a danger to public health and welfare. Newly available evidence about a wide range of observed and projected impacts strengthens the association between the risk of some of these impacts and anthropogenic climate change, indicates that some impacts or combinations of impacts have the potential to be more severe than previously understood, and identifies substantial risk of additional impacts through processes and pathways not considered in the Endangerment Finding.
The Distribution of Environmental Damages
Solomon Hsiang, Paulina Oliva, Reed Walker. Review of Environmental Economics and Policy, Volume 13, Issue 1, Winter 2019, Pages 83–103,
Most regulations designed to reduce environmental externalities impose costs on individuals and firms. A large and growing literature examines whether these costs are disproportionately borne by different sectors of the economy and/or across different groups of individuals. However, much less is known about how the environmental benefits created by these policies are distributed, which mirror the differences in environmental damages associated with existing environmental externalities. We review this burgeoning literature and develop a simple general framework for empirical analysis. We apply this framework to findings concerning the distributional impacts of environmental damages from air pollution, deforestation, and climate change and highlight priorities for future research. A recurring challenge to understanding the distributional effects of environmental damages is distinguishing between cases in which populations are exposed to different levels or changes in an environmental good and those in which an incremental change in the environment may have very different implications for some populations. In the latter case, it is often difficult to empirically identify the underlying sources of heterogeneity in marginal damages because damages may stem from nonlinear and/or heterogeneous damage functions. Nevertheless, understanding the determinants of heterogeneity in environmental benefits and damages is crucial for welfare analysis and policy design.
An Economist’s Guide to Climate Change Science
Hsiang, Solomon, and Robert E. Kopp. 2018. "An Economist's Guide to Climate Change Science." Journal of Economic Perspectives, 32 (4): 3-32.
This article provides a brief introduction to the physical science of climate change, aimed towards economists. We begin by describing the physics that controls global climate, how scientists measure and model the climate system, and the magnitude of human-caused emissions of carbon dioxide. We then summarize many of the climatic changes of interest to economists that have been documented and that are projected in the future. We conclude by highlighting some key areas in which economists are in a unique position to help climate science advance. An important message from this final section, which we believe is deeply underappreciated among economists, is that all climate change forecasts rely heavily and directly on economic forecasts for the world. On timescales of a half-century or longer, the largest source of uncertainty in climate science is not physics, but economics.
Estimating global agricultural effects of geoengineering using volcanic eruptions
Proctor, J., Hsiang, S., Burney, J. et al. Estimating global agricultural effects of geoengineering using volcanic eruptions. Nature 560, 480–483 (2018).
Solar radiation management is increasingly considered to be an option for managing global temperatures, yet the economic effects of ameliorating climatic changes by scattering sunlight back to space remain largely unknown. Although solar radiation management may increase crop yields by reducing heat stress, the effects of concomitant changes in available sunlight have never been empirically estimated. Here we use the volcanic eruptions that inspired modern solar radiation management proposals as natural experiments to provide the first estimates, to our knowledge, of how the stratospheric sulfate aerosols created by the eruptions of El Chichón and Mount Pinatubo altered the quantity and quality of global sunlight, and how these changes in sunlight affected global crop yields. We find that the sunlight-mediated effect of stratospheric sulfate aerosols on yields is negative for both C4 (maize) and C3 (soy, rice and wheat) crops. Applying our yield model to a solar radiation management scenario based on stratospheric sulfate aerosols, we find that projected mid-twenty-first century damages due to scattering sunlight caused by solar radiation management are roughly equal in magnitude to benefits from cooling. This suggests that solar radiation management—if deployed using stratospheric sulfate aerosols similar to those emitted by the volcanic eruptions it seeks to mimic—would, on net, attenuate little of the global agricultural damage from climate change. Our approach could be extended to study the effects of solar radiation management on other global systems, such as human health or ecosystem function.
Higher temperatures increase suicide rates in the United States and Mexico
Burke, M., González, F., Baylis, P. et al. Higher temperatures increase suicide rates in the United States and Mexico. Nature Clim Change 8, 723–729 (2018)
Linkages between climate and mental health are often theorized but remain poorly quantified. In particular, it is unknown whether the rate of suicide, a leading cause of death globally, is systematically affected by climatic conditions. Using comprehensive data from multiple decades for both the United States and Mexico, we find that suicide rates rise 0.7% in US counties and 2.1% in Mexican municipalities for a 1 °C increase in monthly average temperature. This effect is similar in hotter versus cooler regions and has not diminished over time, indicating limited historical adaptation. Analysis of depressive language in >600 million social media updates further suggests that mental well-being deteriorates during warmer periods. We project that unmitigated climate change (RCP8.5) could result in a combined 9–40 thousand additional suicides (95% confidence interval) across the United States and Mexico by 2050, representing a change in suicide rates comparable to the estimated impact of economic recessions, suicide prevention programmes or gun restriction laws.
In the News
Articles and Op-Eds
El Niño: a global weather event that may save California - and destroy the tropics
The Guardian, September 21, 2015
Weather and Violence
New York Times Sunday Review, August 30, 2013
Media Citations
Can We Help the Losers in Climate Change?
MIT Technology Review, August 8, 2016
Climate change could force huge migrations for people and animals living near the equator
Washington Post, June 9, 2016
Climate Change's Bottom Line
New York Times, January 31, 2015
The weather report: Economists are getting to grips with the impact of climate change
Economist, January 16, 2014
Report: Typhoon's long, deadly toll on female infants
CNN, November 20, 2013
Webcasts
California and the Climate Fight: Cal Day 2017
Solomon Hsiang, Ned Helme, Meredith Fowlie, Carol Zabin,
Event: Cal Day 2017
Date: April 22, 2017 Duration: 60 minutes
The Emerging Age of Data-Driven Policy Design: Examples from Trying to Manage the Global Climate
Solomon Hsiang,
Event: 2015 Strata + Hadoop World
Date: February 19, 2015 Duration: 8 minutes
Risky Business: The Economic Risks of Climate Change with Sol Hsiang
Sol Hsiang, Henry E. Brady,
Date: August 10, 2014 Duration: 28 minutes
Quantifying the Economic Cost of Climate Change
Solomon Hsiang,
Date: April 30, 2014 Duration: 20 minutes
Tempers May Flare as Climate Change Heats Up, Study Finds
Solomon Hsiang,
Date: August 7, 2013 Duration: 0 minutes
Last updated on 07/25/2023