Materealistic? How European energy system models exceed raw material reserves
物质现实?欧洲能源系统模型如何超出原材料储备
AI总结 通过系统回顾59项高度脱碳的欧洲能源系统建模研究,并定量评估5种关键技术和19种材料的物质需求,发现材料需求超出欧洲基于人口份额的全球储备,呼吁能源充足性措施以实现能源-物质关系的可持续性。
物质现实?欧洲能源系统模型如何超出原材料储备
Jan Mutke, Jonas Finke, Katharina Esser, Heidi Heinrichs
AI总结 通过系统回顾59项高度脱碳的欧洲能源系统建模研究,并定量评估5种关键技术和19种材料的物质需求,发现材料需求超出欧洲基于人口份额的全球储备,呼吁能源充足性措施以实现能源-物质关系的可持续性。
脱碳能源系统减少了排放和对化石燃料的依赖,但扩大可再生能源增加了对关键原材料的需求。然而,大多数能源系统模型忽视了物质需求,使能源情景的物质可行性受到质疑。我们结合对59项高度脱碳的欧洲能源系统建模研究的系统回顾,以及对5种关键技术和19种材料的物质需求进行定量事后评估。我们发现,对于七种材料(Ga, In, Ir, Te;程度较轻的Ag, Se, V),物质需求超出了欧洲基于人口份额的当前全球储备,特别是当考虑能源系统的多个部门时。非能源需求的竞争进一步加剧了稀缺性,而技术创新既可以缓解也可以加剧这种稀缺性。我们得出结论,能源效率、回收、扩大储备和技术创新可能只能部分解决已识别的短缺问题,并呼吁采取能源充足性措施以实现能源-物质关系的可持续性。
Decarbonising energy systems reduces emissions and fossil fuel dependency, but expanding renewables increases demands for critical raw materials. Most energy system models, however, neglect material demands, putting the material feasibility of energy scenarios at question. We combine a systematic review of 59 highly decarbonised European energy system modelling studies with a quantitative ex-post assessment of material demands for 5 key technologies and 19 materials. We find that material demands exceed Europe's population-based shares of current global reserves for seven materials (Ga, In, Ir, Te; less pronounced for Ag, Se, V), in particular if multiple sectors of the energy system are considered. Competing non-energy demand further amplifies the scarcity, while technological innovation can either alleviate or intensify it. We conclude that energy efficiency, recycling, expanding reserves and technological innovation may only partly address the identified shortages and call for energy sufficiency measures to achieve sustainability in the energy-material nexus.
信贷容量与资金冲击的传导:来自美国和巴西金融中介的证据
Ayush Jha, Ali Jaffri, Frank Fabozzi
AI总结 通过动态结构模型和2002-2025年美巴监管数据,发现美国信贷容量是巴西的3-6倍,导致相同资金冲击在巴西引发更大且更持久的贷款收缩,基线信贷容量差异是跨国传导差异的主因。
为什么相似的资金冲击在不同国家会产生截然不同的信贷结果?我们开发并估计了一个动态结构模型,其中中介信贷容量决定了资金中断向贷款传导的机制。利用2002-2025年美国银行和信用合作社以及巴西银行和合作社的监管数据,我们恢复了机构层面的信贷容量及其在主要危机事件中的动态变化。美国的信贷容量是巴西的三到六倍,而持续性在两国间相似。因此,资金冲击在巴西产生了更大且更持久的贷款收缩。反事实分析表明,基线信贷容量的差异(而非持续性)解释了危机传导和政策有效性的绝大部分跨国差异。
Why do similar funding shocks generate sharply different credit outcomes across countries? We develop and estimate a dynamic structural model in which intermediary credit capacity governs the transmission of funding disruptions to lending. Using supervisory data on U.S. banks and credit unions and Brazilian banks and cooperatives from 2002--2025, we recover institution-level credit capacity and its dynamics across major crisis episodes. Credit capacity is three to six times larger in the United States than in Brazil, while persistence is similar across countries. As a result, funding shocks generate substantially larger and more persistent lending contractions in Brazil. Counterfactual analysis shows that differences in baseline credit capacity, rather than persistence, account for most cross-country variation in crisis propagation and policy effectiveness.
通过可解释机器学习方法识别拉丁美洲后疫情时代低表现学生的决定因素
Marcos Delprato
AI总结 基于2022年PISA数据,使用堆叠模型和SHAP分析,识别拉丁美洲低表现学生的关键决定因素,发现少数语言、留级、无数字设备、贫困家庭、兼职工作及学校劣势是主要风险因素。
引言。拉丁美洲(LAC)学生未达到基本学习能力的比例很高,考虑到该地区深层次的结构性不平等和更大的疫情后学习损失,这令人担忧。在此背景下,本文旨在帮助识别低表现和表现不佳学生(低于2级)的决定因素。方法。基于2022年国际学生评估项目(PISA)中10个LAC国家的数据,使用集成二元分类模型的堆叠模型,并应用Shapley加法解释(SHAP)分析以实现可解释性,我们识别了影响低表现群体学生表现的关键因素。结果。我们发现,最有可能成为未达标学生的学生讲少数语言且曾留级,家中没有数字设备,来自贫困家庭,每周有一半时间打工赚钱,且其所在学校存在广泛劣势,如学校氛围差、信息和通信技术(ICT)基础设施薄弱以及教学质量差(仅三分之一的教师持有资格证书)。对于各国估计,我们发现排名靠前的因素的贡献模式相当一致,其中小学留级、家庭财富和教育ICT投入在10个国家中至少有8个进入前十名协变量。讨论。本文的研究结果有助于广泛研究识别和瞄准拉丁美洲教育系统中被落在后面的学生的策略。
Introduction. The high prevalence of students not achieving basic learning competencies in Latin America (LAC) is concerning, even more so considering the region's deep structural inequalities and the larger post-pandemic learning losses. Within this scenario, the paper aims to contribute to the identification of the determinants of bottom and low performers (below level 2). Methodology. Based on 2022 data from the Programme for International Student Assessment (PISA) for 10 LAC countries, and using a stacking model integrating binary classification models as well as by applying Shapley Additive Explanations (SHAP) analysis for interpretability, we identify critical factors impacting on the student performance across low performers groups. Results. We find that a student with the highest probability of being a not achiever speaks a minority language and had repeated, has no digital devices at home, comes from a poor family and works for payment half of the week, and the school the student attends has wide disadvantages such as bad school climate, weak Information and Communication Technology (ICT) infrastructure and poor teaching quality (only a third of teachers being certified). For countries' estimates, we find quite homogeneous patterns regarding the contribution of top ranked factors, with repetition at primary, household wealth, and educational ICT inputs being top ten ranked covariates in at least 8 out of the 10 total countries. Discussions. The paper findings contribute to the broad literature on strategies to identify and to target those most left behind in Latin American education systems.
Marcos Delprato
Latin America's education systems are fragmented and segregated, with substantial differences by school type. The concept of school efficiency (the ability of school to produce the maximum level of outputs given available resources) is policy relevant due to scarcity of resources in the region. Knowing whether private and public schools are making an efficient use of resources --and which are the leading drivers of efficiency-- is critical, even more so after the learning crisis brought by the COVID-19 pandemic. In this paper, relying on data of 2,034 schools and nine Latin American countries from PISA 2022, I offer new evidence on school efficiency (both on cognitive and non-cognitive dimensions) using Data Envelopment Analysis (DEA) by school type and, then, I estimate efficiency leading determinants through interpretable machine learning methods (IML). This hybrid DEA-IML approach allows to accommodate the issue of big data (jointly assessing several determinants of school efficiency). I find a cognitive efficiency gap of nearly 0.10 favouring private schools and of 0.045 for non-cognitive outcomes, and with a lower heterogeneity in private than public schools. For cognitive efficiency, leading determinants for the chance of a private school of being highly efficient are higher stock of books and PCs at home, lack of engagement in paid work and school's high autonomy; whereas low-efficient public schools are shaped by poor school climate, large rates of repetition, truancy and intensity of paid work, few books at home and increasing barriers for homework during the pandemic.
Andrew Crawley, Adam Daigneault, Jonathan Gendron
Several key states in various regions of the U.S. have experienced recent sawtimber as well as pulp and paper mill closures, which raises an important policy question: how have and will key macroeconomic and industry specific indicators within the U.S. forest sector likely to change over time? This study provides empirical evidence to support forest-sector policy design by using a vector error correction (VEC) model to forecast economic trends in three major industries - forestry and logging, wood manufacturing, and paper manufacturing - across six of the most forest-dependent states found by the location quotient (LQ) measure: Alabama, Arkansas, Maine, Mississippi, Oregon, and Wisconsin. Overall, the results suggest a general decline in employment and the number of firms in the forestry and logging industry as well as the paper manufacturing industry, while wood manufacturing is projected to see modest employment gains. These results also offer key insights for regional policymakers, industry leaders, and local economic development officials: communities dependent on timber-based manufacturing may be more resilient than other forestry-based industries in the face of economic disruptions. Our findings can help prioritize targeted policy interventions and inform regional economic resilience strategies. We show distinct differences across forest-dependent industries and/or state sectors and geographies, highlighting that policies may have to be specific to each sector and/or geographical area. Finally, our VEC modeling framework is adaptable to other resource-dependent industries that serve as regional economic pillars such as mining, agriculture, and energy production offering a transferable tool for policy analysis in regions with similar economic structures.