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.
A new playbook from the International Republican Institute (IRI), the National Democratic Institute (NDI) and the Stanford Internet Observatory (SIO) aims to help identify, respond to, and build long-term resilience to election-related information manipulation, attacks on information integrity and threats to delegitimize elections globally.
We present the results of a cluster-randomized controlled trial that evaluates the effects of a free, center-based parenting intervention on early cognitive development and parenting practices in 100 rural villages in China. We then compare these effects to a previous trial of a home-based intervention conducted in the same region, using the same parenting curriculum and public service system, accounting for potential differences between the studies. We find that the center-based intervention did not have a significant impact on child development outcomes, but did lead to increases in the material investments, time investments, and parenting skills of caregivers. The average impact of the center-based intervention on child skills and investments in children was significantly smaller than the home-visiting intervention. Analysis of the possible mechanisms suggests that the difference in effects was driven primarily by different patterns of selection into program participation.
A forward-thinking manifesto from three Stanford professors—experts who have worked at ground zero of the tech revolution for decades—which reveals how big tech’s obsession with optimization and efficiency has sacrificed fundamental human values and outlines steps we can take to change course, renew our democracy, and save ourselves.
Crop type mapping at the field level is critical for a variety of applications in agricultural monitoring, and satellite imagery is becoming an increasingly abundant and useful raw input from which to create crop type maps. Still, in many regions crop type mapping with satellite data remains constrained by a scarcity of field-level crop labels for training supervised classification models. When training data is not available in one region, classifiers trained in similar regions can be transferred, but shifts in the distribution of crop types as well as transformations of the features between regions lead to reduced classification accuracy. We present a methodology that uses aggregate-level crop statistics to correct the classifier by accounting for these two types of shifts. To adjust for shifts in the crop type composition we present a scheme for properly reweighting the posterior probabilities of each class that are output by the classifier. To adjust for shifts in features we propose a method to estimate and remove linear shifts in the mean feature vector. We demonstrate that this methodology leads to substantial improvements in overall classification accuracy when using Linear Discriminant Analysis (LDA) to map crop types in Occitanie, France and in Western Province, Kenya. When using LDA as our base classifier, we found that in France our methodology led to percent reductions in misclassifications ranging from 2.8% to 42.2% (mean = 21.9%) over eleven different training departments, and in Kenya the percent reductions in misclassification were 6.6%, 28.4%, and 42.7% for three training regions. While our methodology was statistically motivated by the LDA classifier, it can be applied to any type of classifier. As an example, we demonstrate its successful application to improve a Random Forest classifier.
With the rapid rise of China and the relative decline of the United States, the topic of power transition conflicts is back in popular and scholarly attention.
Purpose: To determine the prevalence of visual impairment and glasses ownership among Han Chinese and Hui minority junior high school children in Ningxia Hui Autonomous Region, China.
Design: Population-based cross-sectional study.
Methods: Vision screening was conducted on 20,376 children (age 12–15 years) in all 124 rural junior high schools in Ningxia. Personal and family characteristics, glasses ownership, and academic performance were assessed through a survey questionnaire and standardized mathematics test, respectively.
Results: The prevalence of visual acuity (VA) ≤6/12 in either eye was significantly higher among Han (54.5%) than Hui (45.2%) children (P<0.001), and was significantly positively associated with age, female sex, Han ethnicity, parental outmigration for work, shorter time spent outside during recess, shorter time spent watching television and higher time spent studying. Among children with VA≤6/12 in both eyes, only 56.8% of Han and 41.5% of Hui children had glasses (P<0.001). Glasses ownership was significantly associated with worse vision, greater family wealth, female sex, higher test scores, age, parental outmigration for work, understanding of myopia and glasses, higher time spent studying and Han ethnicity.
Conclusion: One of the first of its kind, this report on Han and Hui ethnic schoolchildren confirms a high prevalence of visual impairment among both populations, but slightly higher among the Han. Both groups, especially the Hui, have low rates of glasses ownership. Future interventions and policies designed to improve glasses usage should focus on populations with lower incomes and seek to correct erroneous beliefs about the safety of glasses and efficacy of traditional eye exercises.
Researchers Shelby Grossman, Renee DiResta and Josh A. Goldstein examine Middle East influence operations across social media, including how regimes incorporated social media activities into their own domestic and foreign policy toolkits. The full paper can be found at the Project on Middle East Political Science website.
Introduction: Inadequate care during early childhood can lead to long-term deficits in skills. Parenting programmes that encourage investment in young children are a promising tool for improving early development outcomes and long-term opportunities in low-income and middle-income regions, such as rural China.
Methods: We conducted a systematic review and a meta-analysis to investigate the prevalence of early developmental delays and stimulating parenting practices as well as the effect of parental training programmes on child development outcomes in rural China. We obtained data in English from EconPapers, PubMed, PsycARTICLES, Cochrane Library, Web of Science and Scopus (Elsevier) and in Chinese from China National Knowledge Infrastructure, Wanfang Data and VIP Information. We conducted frequentist meta-analyses of aggregate data and estimated random-effects meta-regressions. Certainty of evidence was rated according to the Grading of Recommendations Assessment, Development and Evaluation approach.
Results: We identified 19 observational studies on the prevalence of developmental delays and stimulating parenting practices for children under 5 years of age (n=19 762) and ten studies on the impact of parental training programmes on early child development (n=13 766). Children’s risk of cognitive, language and social-emotional delays in the rural study sites (covering 14 provinces mostly in Central and Western China) was 45%, 46%, and 36%, respectively. Parental training programmes had a positive impact on child cognition, language and social-emotional development.
Conclusion: There is evidence to suggest that early developmental delay and the absence of stimulating parenting practices (ie, reading, storytelling and singing with children) may be prevalent across rural, low-income and middle-income regions in Central and Western China. Results support the effectiveness of parental training programmes to improve early development by encouraging parental engagement.
A new publication from the Center for Research on Foundation Models (CRFM) at Stanford University, with contributions by Shelby Grossman and others from the Stanford Internet Observatory
It is well-established that the Conquest of the Americas by Europeans led to catastrophic declines in indigenous populations. However, less is known about the conditions under which indigenous communities were able to overcome the onslaught of disease and violence that they faced. Drawing upon a rich set of sources, including Aztec tribute rolls and early Conquest censuses (chiefly the Suma de Visita} (1548)), we develop a new disaggregated dataset on pre-Conquest economic, epidemiological and political conditions both in 11,888 potential settlement locations in the historic core of Mexico and in 1,093 actual Conquest-era city-settlements. Of these 1,093 settlements, we show that 36% had disappeared entirely by 1790. Yet, despite being subject to Conquest-era violence, subsequent coercion and multiple pandemics that led average populations in those settlements to fall from 2,377 to 128 by 1646, 13% would still end the colonial era larger than they started. We show that both indigenous settlement survival durations and population levels through the colonial period are robustly predicted, not just by Spanish settler choices or by their diseases, but also by the extent to which indigenous communities could themselves leverage non-replicable and non-expropriable resources and skills from the pre-Hispanic period that would prove complementary to global trade. Thus indigenous opportunities and agency played important roles in shaping their own resilience.
Objective: Consultation length, the time spent between patient and health care provider during a visit, is an essential element in measuring quality of health care patients receive from a primary care facility. However, the linkage between consultation length and process quality and diagnosis quality of primary care is still uncertain. This study aims to examine the role consultation length plays in delivering process quality and diagnosis quality, two central components of overall primary care quality, in rural China.
Methods: We recruited unannounced standardized patients (SPs) to present classic symptoms of angina and tuberculosis in selected healthcare facilities in three provinces of China. The consultation length and primary care quality of SPs were measured and compared with both international and national standards of care. Ordinary Least Squares (OLS) regressions for process quality (continuous dependent variable) and Logistic regressions for diagnosis quality (binary dependent variable) were performed to investigate the relationship between consultation length and primary care quality.
Results: The average consultation lengths among patients with classic symptoms of angina and those with symptoms of tuberculosis were approximately 4.33 min and 6.28 min, respectively. Providers who spent more time with patients were significantly more likely to complete higher percentage of recommended checklist items of both questions and examinations for angina (β = 1.39, 95%CI 1.01–1.78) and tuberculosis (β = 0.89, 95%CI 0.69–1.08). Further, providers who spent more time with patients were more likely to make correct diagnosis for angina (marginal effect = 0.014, 95%CI 0.002–0.026) and for tuberculosis (marginal effect = 0.013, 95%CI 0.005–0.021).
Conclusions: The average consultation length is extremely short among primary care providers in rural China. The longer consultation leads to both better process and diagnosis quality of primary care.
Practice Implications: We recommend primary care providers to increase the length of their communication with patients. To do so, government should implement healthcare reforms to clarify the requirements of affordable and reliable consultation length in medical care services. Moreover, such an experience can also be extended to other developing countries.
The Project on Middle East Political Science partnered with Stanford University’s Center for Democracy, Development and the Rule of Law and its Global Digital Policy Incubator for an innovative two week online seminar to explore the issues surrounding digital activism and authoritarianism. This workshop was built upon more than a decade of our collaboration on issues related to the internet and politics in the Middle East, beginning in 2011 with a series of workshops in the “Blogs and Bullets” project supported by the United States Institute for Peace and the PeaceTech Lab. This new collaboration brought together more than a dozen scholars and practitioners with deep experience in digital policy and activism, some focused on the Middle East and others offering a global and comparative perspective. POMEPS STUDIES 43 collects essays from that workshop, shaped by two weeks of public and private discussion.
Many countries have undertaken large and high-profile payment-for-ecosystem-services (PES) programs to sustain the use of their natural resources. Nevertheless, few studies have comprehensively examined the impacts of existing PES programs. Grassland Ecological Compensation Policy (GECP) is one of the few pastorally focused PES programs with large investments and long duration, which aim to improve grassland quality and increase herder income. Here we present empirical evidence of the effects of GECP on grassland quality and herder income. Through a thorough and in-depth econometric analysis of remote sensing and household survey data, we find that, although GECP improves grassland quality (albeit to only a small extent) and has a large positive effect on income, it exacerbates existing income inequality among herders within their local communities. The analysis demonstrates that the program has induced herders to change their livestock production behavior. Heterogeneity analysis emphasizes the importance of making sure the programs are flexible and are adapted to local resource circumstances.
