At the intersection of physical sciences and policy, our researchers work to find solutions for hunger, environmental degradation, emerging energy markets and more.
Research Spotlight
Economic Policy Challenges Facing California's Next Governor: Electricity Policy Reform
Because Californians are likely to want to continue to lead the energy transition, the relevant policy design question is: How can the state achieve these low-carbon energy goals in a more cost- effective manner?
Climate Change is Increasing the Risk of Extreme Autumn Wildfire Conditions Across California
The climate model analyses presented here suggest that continued climate change will further amplify the number of days with extreme fire weather by the end of this century, though a pathway consistent with the UN Paris commitments would substantially curb that increase.
Sight for Sorghums: Comparisons of Satellite- and Ground-Based Sorghum Yield Estimates in Mali
Leveraging a survey experiment in Mali, this study uses plot-level sorghum yield estimates, based on farmer reporting and crop cutting, to construct and evaluate estimates from three satellite-based sensors.
Putin didn’t explicitly state what those consequences would be, or what attacks he had in mind. But to anyone listening, the message was clear enough. If the West directly intervened in Ukraine, Russia would use its nuclear arsenal.
The International Journal of Press/Politics,
August 8, 2022
Government censorship—internet shutdowns, blockages, firewalls—impose significant barriers to the transnational flow of information despite the connective power of digital technologies. In this paper, we examine whether and how information flows across borders despite government censorship. We develop a semi-automated system that combines deep learning and human annotation to find co-occurring content across different social media platforms and languages. We use this system to detect co-occurring content between Twitter and Sina Weibo as Covid-19 spread globally, and we conduct in-depth investigations of co-occurring content to identify those that constitute an inflow of information from the global information ecosystem into China. We find that approximately one-fourth of content with relevance for China that gains widespread public attention on Twitter makes its way to Weibo. Unsurprisingly, Chinese state-controlled media and commercialized domestic media play a dominant role in facilitating these inflows of information. However, we find that Weibo users without traditional media or government affiliations are also an important mechanism for transmitting information into China. These results imply that while censorship combined with media control provide substantial leeway for the government to set the agenda, social media provides opportunities for non-institutional actors to influence the information environment. Methodologically, the system we develop offers a new approach for the quantitative analysis of cross-platform and cross-lingual communication.
This book created the field of the law of democracy, offering a systematic account of the legal construction of American democracy. This edition represents a significant revision that reflects the embattled state of democracy in the U.S. and abroad.
China has witnessed rapid increases in the skill premium over the last few decades. In this paper, we study the short-run effect of capital goods imports on skill premium in China. The surge in capital goods imports, which embody advanced technology, can explain the rising demand for skill in China. We exploit regional variations in capital goods import exposure stemming from initial differences in import structure and instrument for the capital goods import growth using exchange rate movements. A city at the 75th percentile of the distribution of capital goods imports growth has a higher skill premium by 5 percentage points (0.38 standard deviation) over the one at the 25th percentile. To explore the underlying mechanism, we provide firm-level evidence and show that imported capital goods are skill-complementary.
Key policy takeaways from Rose Gottemoeller on NATO’s new strategic concept, Francis Fukuyama on the Jan. 6 connection with the war in Ukraine, Michael McFaul on the West arming Ukraine, Amy Zegart on future U.S. cyber policy, Daniel Sneider on Japan after Shinzo Abe, and Riana Pfefferkorn on abortion and data collection.
Background
High adherence and proper usage of micronutrient powder (MNP) influence child nutritional outcomes, yet few studies explore the role of delivery patterns. This study explores the association between MNP delivery patterns and MNP feeding behaviors among Han and minority caregivers in rural Western China.
Methods
In August 2019, a total of 1021 caregiver-child pairs were selected through a four-stage cluster sampling process. A cross-sectional survey collected information on caregiver demographics, MNP delivery patterns (channel and frequency), and MNP feeding behaviors (proper usage and adherence). Using logistic regression, we examined which delivery channels and delivery frequencies were associated with proper usage and high adherence.
Results
The results indicated that minority caregivers had lower levels of proper MNP usage than did Han caregivers (89.2%), with Tibetan caregivers’ reporting the lowest rates of adherence (32.6%). Logistic regression revealed that that township-based channel was significantly correlated with proper usage among Tibetan and Yi caregivers (Odds Ratio, OR = 2.0, p < 0.01; and OR = 3.5, p < 0.001). Overall, the township-based and home-visit channels were significantly correlated with high adherence (OR = 1.7 and OR = 2.3, respectively; p < 0.001); delivery frequency was significantly correlated with high adherence (2 months: OR = 2.2, p < 0.001 and ≤ 1 month: OR = 3.5, p < 0.001) but not correlated with proper usage among the whole sample and individual ethnic groups.
Conclusions
In conclusion, the study finds evidence of a correlation between MNP delivery channel and both proper usage and high adherence as well as a correlation between MNP delivery frequency and high adherence.
In many developing countries, low population density may be a major reason for low school participation in rural areas, and the problem is likely to worsen with rapid urbanization. However, few studies have investigated empirically the role of population density in rural education, especially the moderating effect of population density on the outcomes of education policies. This study aims to fill this gap in the literature. From 1999 through the early 2000s, China launched a set of major nationwide policies aimed at universalizing 9-year compulsory education in rural areas. Using differencein- differences and triple difference strategies, we show that the policies significantly increased the probability of junior high school enrollment of rural children and, more importantly, these policies were more effective in densely populated regions. These fi ndings confi rm the importance of population density to rural education.
Transparency is essential to getting every other part of platform regulation right. But defining sound transparency rules—identifying what information is needed most from platforms like Twitter or YouTube, and how to get it—is quite complicated.
Responding to Elon Musk’s proposed acquisition of Twitter, Daphne Keller suggests that “middleware” models, not common carriage rules, best put control over internet speech regulation in the hands of users.
The U.S. Centers for Disease Control and Prevention (CDC) is responsible for preventing the introduction, transmission, and spread of communicable diseases into the United States. It does this primarily through the Division of Global Migration and Quarantine (DGMQ), which oversees the federal quarantine station network. Over the past two decades, the frequency and volume of microbial threats worldwide have continued to intensify. The COVID-19 pandemic, in particular, has prompted a reevaluation of many of our current disease control mechanisms, including the use and role of quarantine as a public health tool.
The emergence of COVID-19 prompted CDC to request that the National Academies of Sciences, Engineering, and Medicine convene a committee to assess the role of DGMQ and the federal quarantine station network in mitigating the risk of onward communicable disease transmission in light of changes in the global environment, including large increases in international travel, threats posed by emerging infections, and the movement of animals and cargo. The committee was also tasked with identifying how lessons learned during COVID-19 and other public health emergencies can be leveraged to strengthen pandemic response. The report's findings and recommendations span five domains: organizational capacity, disease control and response efforts, new technologies and data systems, coordination and collaboration, and legal and regulatory authority.
Decision models can combine information from different sources to simulate the long-term consequences of alternative strategies in the presence of uncertainty. A cohort state-transition model (cSTM) is a decision model commonly used in medical decision making to simulate the transitions of a hypothetical cohort among various health states over time. This tutorial focuses on time-independent cSTM, in which transition probabilities among health states remain constant over time. We implement time-independent cSTM in R, an open-source mathematical and statistical programming language. We illustrate time-independent cSTMs using a previously published decision model, calculate costs and effectiveness outcomes, and conduct a cost-effectiveness analysis of multiple strategies, including a probabilistic sensitivity analysis. We provide open-source code in R to facilitate wider adoption. In a second, more advanced tutorial, we illustrate time-dependent cSTMs.
Key policy takeaways from Michael McFaul on helping Russians who oppose Putin; Kathryn Stoner on how Putin's War has ruined Russia; Steven Pifer on U.S.-Russia relations; Rose Gottemoeller on U.S. policy towards China in the Pacific region; David Studdert on the risks of guns in the home; Herb Lin on cybersecurity, and Hakeem Jefferson on the Jan. 6 hearings.
