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.
We present evidence from a randomized experiment testing the impacts of a six-month early childhood home-visiting program on child outcomes at school entry. Two and a half years after completion of the program, we find persistent effects on child working memory - a key skill of executive functioning that plays a central role in children's development of cognitive and socio-emotional skills. We also find that the program had persistent effects on parental time investments and preschool enrollment decisions. Children were enrolled earlier and in higher quality preschools, the latter reflecting a shift in preferences over preschool attributes toward quality. Our findings imply an important role for the availability of high-quality subsequent schooling in sustaining the impacts of early intervention programs.
High resolution crop type maps are an important tool for improving food security, and remote sensing is increasingly used to create such maps in regions that possess ground truth labels for model training. However, these labels are absent in many regions, and models trained in other regions on typical satellite features, such as those from optical sensors, often exhibit low performance when transferred. Here we explore the use of NASA's Global Ecosystem Dynamics Investigation (GEDI) spaceborne lidar instrument, combined with Sentinel-2 optical data, for crop type mapping. Using data from three major cropped regions (in China, France, and the United States) we first demonstrate that GEDI energy profiles are capable of reliably distinguishing maize, a crop typically above 2m in height, from crops like rice and soybean that are shorter. We further show that these GEDI profiles provide much more invariant features across geographies compared to spectral and phenological features detected by passive optical sensors. GEDI is able to distinguish maize from other crops within each region with accuracies higher than 84\%, and able to transfer across regions with accuracies higher than 82\% compared to 64\% for transfer of optical features. Finally, we show that GEDI profiles can be used to generate training labels for models based on optical imagery from Sentinel-2, thereby enabling the creation of 10m wall-to-wall maps of tall versus short crops in label-scarce regions. As maize is the second most widely grown crop in the world and often the only tall crop grown within a landscape, we conclude that GEDI offers great promise for improving global crop type maps.
This Article reframes transitional justice as communication. It argues that the impact of truth and reconciliation commissions (TRCs) and international criminal tribunals (ICTs) on countries where human rights violations occurred depends largely on these institutions changing what those countries’ citizens and elites know and believe. More precisely: most of the ways TRCs and ICTs could advance their goals—such as reconciliation and deterrence—require informing these domestic audiences about the institutions’ activities, methods, and findings, and persuading them to accept the institutions’ conclusions. Communication-specific activities, such as public outreach and media relations, are essential. Yet shaping elite and popular knowledge and opinion are not mere add-ons to what some see as TRCs’ and ICTs’ “core” work: investigating human rights violations, holding hearings, writing reports, and indicting and trying perpetrators. Rather, the imperative of influencing local people must shape how these institutions conduct those activities and sometimes even what conclusions they reach. Unfortunately, TRC commissioners, ICT judges and prosecutors, and their staff, along with transitional justice scholars, have underestimated the importance of influencing domestic audiences for advancing TRCs’ and ICTs’ goals. As a result, the institutions have devoted too little attention and resources to communication.
The Article also provides a typology of the activities and occasions through which TRCs and ICTs can influence domestic audiences. It offers examples of effective and ineffective practice from five international criminal tribunals, such as the International Criminal Court and Special Court for Sierra Leone, and over a dozen truth commissions, such as South Africa's Truth and Reconciliation Commission. Where evidence permits, it assesses individual institutions’ performance. Finally, the Article analyzes the most important challenges that TRCs and ICTs encounter in communicating with domestic audiences.
American Political Science Review,
November 1, 2021
This paper stands at the intersection of two literatures—on partisan polarization and on democratic deliberation—that have not had much connection with one another. If readers find some of the results surprising, the authors have had the same reaction. In this paper we describe these results and our approach to explaining them.
Research in developed countries has found that paternal involvement has positive and significant effects on early childhood development (ECD). Less is known, however, about the state of paternal involvement and its influence on ECD in rural China. Using data collected in Southern China that included 1,460 children aged 6–42 months and their fathers (as well as their primary caregivers), this study examines the association between paternal involvement and ECD. Although the results demonstrate that the average level of paternal involvement is low in rural China, paternal involvement is related to a significant increase in three domains of ECD (cognition, language, and social-emotional skills). Older children benefit significantly more than do younger children from paternal involvement in all domains of ECD. The results also show that, if the mother is the primary caregiver, the mother’s higher educational level and the family’s higher socioeconomic status are positively associated with paternal involvement.
The Texas National Security Review,
October 1, 2021
Emerging and disruptive technologies spell an uncertain future for second-strike retaliatory forces. New sensors and big data analysis may render mobile missiles and submarines vulnerable to detection. I call this development the “standstill conundrum”: States will no longer be able to assure a nuclear response should they be hit by a nuclear first strike. If the nuclear weapons states can manage this vulnerability, however, they might be able to escape its worst effects. “Managing” could mean shoring up nuclear deterrence; it could mean focusing more on defenses; or it could mean negotiating to ensure continued viability of second-strike deterrent forces.
