Urban density and the metabolic reach of metropolitan areas: A panel analysis of per capita transportation emissions at the county-level

We engage a tension in the urban environment literature that positions cities as both drivers of environmental destruction and loci of environmental protection. We argue that the traditional binary view of cities as either harmful or beneficial is too simplistic; we advance a more nuanced understanding of cities to study their internal and external metabolic effects in terms of carbon emissions from on-road transportation at the county-level across the continental United States between 2002 and 2007. First, utilizing satellite imagery from the National Land Cover Database, we create a novel measure of population density by quantifying the number of people per square mile of impervious surface area. Second, we develop a measure of metropolitan adjacency from the rural classifications datasets published by the USDA. In spatial regression models, we find that while higher density reduces emissions, counties that are geographically isolated from metropolitan areas actually have lower per capita emissions, all else equal. We elaborate on the conceptual, methodological, and practical implications of our study in the conclusion.     

中国居民最终需求的碳排放测算

 居民最终需求已成为我国碳排放量增长的重要原因。为了测算我国居民因最终需求而直接和间接排放的碳,本文以1992-2007年价值型投入产出表为基础,结合能源消费实物量数据,编制出混合单位的能源投入产出表,从而得到居民碳间接排放量占居民碳排总量70%以上且呈上升趋势的结论。在能源投入产出表的基础上,通过结构分解模型,对居民最终需求及相关经济活动引致的碳间接排放量进行分解分析,结果表明：居民最终需求总量、城乡消费比例及居民消费结构三个因素的变化是促进碳间接排放量增加的因素,以能源消耗系数下降为特征的生产技术进步是促使CO2间接排放量减少的主要因素。     

Urban forest biomass estimates: is it important to use allometric relationships developed specifically for urban trees?

Many studies have analyzed the benefits, costs, and carbon storage capacity associated with urban trees. These studies have been limited by a lack of research on urban tree biomass, such that estimates of carbon storage in urban systems have relied upon allometric relationships developed in traditional forests. As urbanization increases globally, it is becoming important to more accurately evaluate carbon dynamics in these systems. Our goal was to understand the variability and range of potential error associated with using allometric relationships developed outside of urban environments. We compared biomass predictions from allometric relationships developed for urban trees in Fort Collins, Colorado to predictions from allometric equations from traditional forests, at both the individual species level and entire communities. A few of the equations from the literature predicted similar biomass to the urban-based predictions, but the range in variability for individual trees was over 300%. This variability declined at increasingly coarse scales, reaching as low as 60% for a street tree community containing 11 tree species and 10, 551 trees. When comparing biomass estimates between cities that implement various allometric relationships, we found that differences could be a function of variability rather than urban forest structure and function. Standardizing the methodology and implementing averaged equations across cities could be one potential solution to reducing variability; however, more accurate quantification of biomass and carbon storage in urban forests may depend on development of allometric relationships specifically for urban trees.     

加利福尼亚州温室气体排放权交易项目简介

美国《加利福尼亚州全球变暖应对法案》是地方应对气候变化措施的典型代表,其最引人注目之处在于创立了世界上最广泛且最复杂的温室气体排放权交易体系。该法案的碳减排目标设定及其对温室气体排放权交易体系的碳排放总量、覆盖范围、碳配额抵消与存储机制、报告与履行程序、与其他排放权交易体系对接等问题的制度安排,对应对气候变化法律的构建与完善具有先锋榜样意义,同时也彰显出在应对气候变化问题上地方措施的重要作用。     

On the intensity of downside risk aversion

The degree of downside risk aversion (or equivalently prudence) is so far usually measured by . We propose here another measure, , which has specific and interesting local and global properties. Some of these properties are to a wide extent similar to those of the classical measure of absolute risk aversion, which is not always the case for . It also appears that the two measures are not mutually exclusive. Instead, they seem to be rather complementary as shown through an economic application dealing with a simple general equilibrium model of savings.

The Effect of Board of Directors’ IT Awareness on CIO Compensation and Firm Performance

Chief information officers (CIOs) play increasingly strategic roles in firms in this competitive global economy, which is now largely powered by information technology (IT). However, research has shown a lack of board of directors’ oversight on CIO‐ and IT‐related issues. Drawing on agency, resource dependence, and alignment theories, we investigate the effect of board of directors’ IT awareness on CIO compensation structure and firm performance. We conduct cross‐sectional time series analyses of data collected from various sources. Our study underlines three important findings. First, we show that some commonly known executive compensation determinants, such as individual characteristics and governance structure, do not have significant effects on CIO compensation structure. Second, with regard to CIO compensation structure, firms respond to increasing information asymmetry differently according to the level of IT awareness of their boards. Finally, firms perform better when their boards have higher levels of IT awareness, and this positive effect of IT awareness is considerably larger in IT intensive industries. Overall, our study provides empirical support for the important role of boards’ IT awareness in shaping CIO compensation and improving firm performance. Our results suggest that boards with functional area knowledge—or higher IT awareness in this case—can more effectively monitor and better incentivize executives, and consequently lead to better firm performance.     

碳减排约束下的上海对外贸易商品结构优化政策研究

在我国面临碳减排压力和国际贸易绿色低碳壁垒的背景下,实行经济转型和对外贸易低碳化具有重要的现实意义。本文通过估算出的上海制造业行业的单位产值碳排放量为依据,针对上海对外贸易商品结构的优化进行分析,提出上海对外贸易商品结构优化的机制设计与相应的政策建议,促进上海＂四个中心＂建设和实现＂十二五＂碳减排目标。     

《京都议定书》的森林碳汇及其在中国实施的法律制度完善

中国目前获得签发及正在实施的森林碳汇项目主要有三种类型：CDM碳汇造林项目,中国绿色碳基金支持开展的碳汇造林项目以及其它碳汇造林项目。当前影响中国碳林碳汇发展的主要因素：国际法的国内适用问题,国内林权制度改革的冲突。中国森林碳汇法律制度完善的主要内容：行政许可及行政监督权力的立法完善,立法促进国内碳汇的发展与国际碳市场的衔接与交易流通。     

利用工业废硅胶制活性白炭黑

工业废硅胶用一定浓度的氢氧化钠处理，经过滤得水玻璃．在其中同时加入氯化钠溶液和稀硫酸，经酸化、过滤、水洗、干燥得活性白炭黑，产品指标和橡胶补强性能均达到有关标准.     

Tumour incidence, prevalence and lethality estimation in the absence of cause-of-death information

Summary.  A Bayesian intensity model is presented for studying a bioassay problem involving interval-censored tumour onset times, and without discretization of times of death. Both tumour lethality and base-line hazard rates are estimated in the absence of cause-of-death information. Markov chain Monte Carlo methods are used in the numerical estimation, and sophisticated group updating algorithms are applied to achieve reasonable convergence properties. This method was tried on the rat tumorigenicity data that have previously been analysed by Ahn, Moon and Kodell, and our results seem to be more realistic.