We celebrated our fourth year of research and office basketball with some Chinese food!
Publication: letter on Ivory trade policy in Science /
Alongside a large interdisciplinary team, Sol coauthored a letter today in Science today explaining that recommendations to limit trade in legal ivory are based on evidence-based research. This was a response to an earlier article by Biggs et al. arguing that recommendations to limit trade were based on arbitrary values. We also point out that transparency in international negotiations are an important element of the process, in contrast to the recommendation by Biggs et al. to speed up international decision-making by negotiating international trade in ivory behind closed doors.
Read the letter here.
Read research by the lab on the global black market for ivory and international trade policy experiments here.
Comment in Nature: Climate and conflict research can support policy decision-making /
Marshall Burke and Sol Hsiang wrote a short response to a recent editorial in Nature. The editorial was itself a response to an article in Nature Climate Change that argued that climate-conflict research contained systematic sampling bias. The published Correspondence is pretty succinct:
“Your Editorial on sampling bias in studies linking climate change with civil unrest (Nature 554, 275–276; 2018) is based on an analysis that in our view provides no evidence for biased results (C. Adams et al. Nature Clim. Change 8, 200–203; 2018).
We disagree with your contention that it is “undesirable” to study risk factors for populations with a high likelihood of conflict on the grounds that it could “stigmatize” these regions as politically unstable. The same logic would argue against studying risk factors for people who have a high chance of developing cancer for fear of stigmatizing patients. In our view, such recommendations could create bias in the literature by inhibiting research.
Studies of connections between climate and conflict should instead be motivated to identify causes of human suffering so that it can be alleviated (see, for example, M. Burke et al. Annu. Rev. Econ. 7, 577–617; 2015). We do not believe that shying away from investigations in this field is an effective path towards this goal.”
Publication: Effect of Temperature on Math performance and learning /
Joshua Graff Zivin, Matthew Neidell and Sol Hsiang published a new article "Temperature and human capital in the short and long run". Analyzing over 24,000 student exams and following individual students over time, they demonstrate that cognitive performance in mathematics declines at high temperatures, but not in reading or verbal exams.
Read the article here.
Paper: Pricing climate /
Tatyana Deryugina and Solomon Hsiang have a new NBER working paper out titled "The Marginal Product of Climate". The analysis develops a formal theory for how overall economic productivity due to the climate should be valued, accounting for the fact that populations adapt to changes in their climate. They apply their approach to data on the United States and estimate that "business as usual" warming is worth roughly $6.7 trillion in foregone production within the US market economy.
Read the paper here.
Publication: Climate Damage in the United States /
James Rising, Solomon Hsiang, and former lab member Amir Jina, along with other teammates from the Climate Impact Lab, have a new paper out in Science calculating economic damages from climate change in the United States.
The analysis is the first to construct a "damage function" using micro-level econometric results for a large number of sectors, linked to the full suite of climate models used in CMIP5. Because the analysis has high spatial resolution, it is able to resolve how impacts of unmitigated climate damages across the country will vary, demonstrating that it will substantially increase economic inequality.
See the paper and an interactive visualization of results.
Update: The team at the Associated Press did a really nice interactive visualization of the results:
Carleton named 30 under 30 by Pacific Standard /
We're super proud that Tamma Carleton, one of our doctoral fellows, was named one of the top 30 Thinkers Under 30 in Policy and Social Justice by the Pacific Standard! You can read Carleton's profile here.
“As the human environmental footprint takes on a global scale, I feel that each day I have two choices. One is to shrink back from this problem and decide that as an individual I cannot influence its evolution. The other is to do everything I can to try to inform solutions. Most days, I choose the latter.”
Climate Impact Lab Interactive Maps Launch + NYT Feature /
Two big things happened today. First, our team at the Climate Impact Lab launched an interactive data visualization page where many of our results will be featured as we produce them. You can zoom to the future and see probabilistic outcomes at unprecedented resolution (>24,000 individual regions!).
Second, the New York Times featured the the Impact Lab's work and built their own visualization to illustrate the changing frequency of extremely hot days expected in the future.
Rising to LSE /
James Rising has accepted a position as an Assistant Profess at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics!
Bell to Landcare Research /
Dr. Kenny Bell has accepted a research position at Landcare Research!
González to PUC Chile /
Dr. Felipe González has accepted a position as Assistant Professor of Economics at the Pontificia Universidad Católica de Chile!
Obama cites GPL climate economics research /
In his recent Science article The Irreversible Momentum of Clean Energy, President Obama jumped into the "growth vs. levels" debate among empirical economists studying the effects of climate change, writing
[E]vidence is mounting that any economic strategy that ignores carbon pollution will impose tremendous costs to the global economy and will result in fewer jobs and less economic growth over the long term. Estimates of the economic damages from warming of 4°C over preindustrial levels range from 1% to 5% of global GDP each year by 2100 ... In addition, these estimates factor in economic damages but do not address the critical question of whether the underlying rate of economic growth (rather than just the level of GDP) is affected by climate change, so these studies could substantially understate the potential damage of climate change on the global macroeconomy (8, 9).
and citing the recent GPL paper on the global effects of temperature on growth.
Talk about a president who gets into the nuts and bolts...
Paper: Understanding farmer crop choice in response to climate change /
James Rising has a new working paper Weather-driven adaptation in perennial crop systems:An integrated study of Brazilian coffee yields, demonstrating how farmers in Brazil cope with changing environmental conditions by altering the portfolio of coffee crops they maintain. The analysis develops a novel structural Bayesian modeling approach that embeds reduced form modeling estimates, allowing James to solve (for the first time) the well-known "problem with perennials", i.e. the fact that analysts and policy-makes cannot generally observe the number of long-live plants (perennials) that farmers maintain on a farm. The analysis is important because it demonstrates how farmers cope with a changing climate by changing their investment decisions, sometimes amplifying the economic impact of changes in climate.
Paper: Non-linear network behavior of protesters during escalating social movements /
Felipe Gonzalez has a new working paper Collective Action in Networks: Evidence from the Chilean Student Movement, demonstrating how millions of students across schools in Chile influence one another to participate in a growing social movement. Felipe demonstrates how the number of individuals in each student's social network, in addition to each student's physical neighborhood, increases the likelihood that specific students will participate in the 2011 student movement. He finds strong evidence of a "tipping point" where if 40% of a student's class is participating, then the entire class "tips" and begins attending the protest. This is important because it is the first empirical evidence testing classical models of social network dynamics in revolutionary environments.
Locations of over 50,000 student protesters in Santiago, Chile during the 2011 student movement
Publication: Social and economic impacts of climate /
Tamma Carleton and Solomon Hsiang published an article in Science discussing and synthesizing the methods and results used to understand the impact of climate from the last decade. We demonstrate how findings across the literature and sectors are linked, identify commonalities across numerous studies, and compute how much (i) various aspects of the current climate contribute to to historical social outcomes, (ii) how much climate change to date has affected outcomes, and (iii) quantitative projections of the future. We identify that understanding "adaptation gaps" is the most important area for future research.