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.
With the New START Treaty supended by the Russian Federation the future of legal nuclear arms control looks even bleaker than before. This brief lays out the foundations of the treaty and the main obstacles that it faces even before it expires in 2026.
Social media has been fully integrated into the lives of most adolescents in the U.S., raising concerns among parents, physicians, public health officials, and others about its effect on mental and physical health. Over the past year, an ad hoc committee of the National Academies of Sciences, Engineering, and Medicine examined the research and produced this detailed report exploring that effect and laying out recommendations for policymakers, regulators, industry, and others in an effort to maximize the good and minimize the bad. Focus areas include platform design, transparency and accountability, digital media literacy among young people and adults, online harassment, and supporting researchers.
Regional monopoly limits market reforms from improving cross-firm resource allocative efficiency, but little empirical evidence is available from developing countries. This paper provides rich evidence that regional monopoly may hinder the expansion of more productive firms, using the Chinese iron and steel sector as a case. Drawing on a comprehensive panel dataset comprising 11,136 iron and steel firms in China from 1998 to 2009, we demonstrate that market reforms in China's steel industry enhance competition at the national level, but do not effectively improve resource reallocation within provinces. Despite a decline in the market share of the top 10 largest steel enterprises from 80% to 50% between 1998 and 2009, resource reallocation only contributes to 14% of industry-level total factor productivity (TFP) growth, amounting to one-sixth of the contribution from within-firm productivity growth. Furthermore, the effects of resource reallocation within provinces are significantly lower compared to those observed between provinces, suggesting that market fragmentation or frictions hinder the expansion of more productive firms within the same province. These findings underscore the importance of eliminating regional monopoly for developing countries undergoing market reforms to enhance resource allocative efficiency.
Breastfeeding self-efficacy (BSE), defined as a mother’s confidence in her ability to breastfeed, has been confirmed to predict the uptake of exclusive breastfeeding (EBF). Early experiences during the birth hospital stay, especially in-hospital formula feeding (IHFF), can impact both EBF and maternal breastfeeding confidence. Therefore, our objective was to examine the association between IHFF and EBF outcomes and investigate whether this association is influenced by BSE. The study included 778 infants from a larger cohort study conducted in 2021, with a one-year follow-up in rural areas of Sichuan Province, China. We used a causal mediation analysis to estimate the total effect (TE), natural direct (NDE), and nature indirect effects (NIE) using the paramed command in Stata. Causal mediation analyses revealed that IHFF was negatively associated with EBF (TE odds ratio = 0.47; 95% CI, 0.29 to 0.76); 28% of this association was mediated by BSE. In the subgroup analysis, there were no significant differences in the effects between parity subgroups, as well as between infant delivery subgroups. Our study found that IHFF hindered later EBF and that BSE mediated this association. Limiting the occurrence of in-hospital formula feeding or improving maternal breastfeeding self-efficacy is likely to improve exclusive breastfeeding outcomes.
Journal of Research on Educational Effectiveness,
December 7, 2023
The objective of the current study is to examine the impact of an in-school computer-assisted learning (CAL) intervention on the math achievement of rural students in Taiwan, including a marginalized subgroup of rural students called Xinzhumin, and the factors associated with this impact. In order to achieve this, we conducted a cluster randomized controlled trial involving 1,840 fourth- and fifth-grade students at 95 schools in four relatively poor counties and municipalities of Taiwan during the spring semester of 2019. While the Intention-To-Treat (ITT) analysis found that the CAL intervention had no significant impacts on student math achievement, the Local Average Treatment Effect (LATE) analysis revealed significant associations with the math performance of the most active 20% of students in the treatment group. LATE estimates suggest that using CAL for more than 20 minutes per week for ten weeks corresponds to higher math test scores, both in general (0.16 SD–0.22 SD), and for Xinzhumin students specifically (0.3 SD–0.34 SD). Teacher-level characteristics were associated with compliance rates.
