The Role of Cancer Risk in the Regulation of Industrial Pollution

The extent of carcinogen regulation under existing U.S. environmental statutes is assessed by developing measures of the scope and stringency of regulation. While concern about cancer risk has played an important political role in obtaining support for pollution control programs, it has not provided the predominant rationale for most regulatory actions taken to date. Less than 20% of all standards established to limit concentrations of chemicals in various media address carcinogens. Restrictions on chemical use are more frequently based on concerns about noncancer human health or ecological effects. Of the chemicals in commercial use which have been identified as potential human carcinogens on the basis of rodent bioassays, only a small proportion are regulated. There is an inverse relationship between the scope of regulatory coverage and the stringency of regulatory requirements: the largest percentages of identified carcinogens are affected by the least stringent requirements, such as information disclosure. Standards based on de minimis cancer risk levels have been established for only 10% of identified carcinogens and are restricted to one medium: water. Complete bans on use have affected very few chemicals. The general role that carcinogenicity now plays in the regulatory process is not dramatically different from that of other adverse human health effects: if a substance is identified as a hazard, it may eventually be subject to economically achievable and technically feasible restrictions.     

A Process for Incorporating Comparative Risk into Environmental Policymaking in Louisiana

The goal of Louisiana's 1990–1991 comparative risk project, also called the Louisiana Environmental Action Plan (LEAP), was to incorporate risk assessment into state environmental planning and policymaking. Scientists, government officials, and citizens were brought together to estimate the relative risk to human health, natural resources, and quality of life posed by 33 selected environmental issues. The issues were then ranked according to their relative estimated risks. It was hoped that this ranking of "comparative risks" would enable state policymakers to target the most important environmental problems and allocate scarce public resources more rationally and efficiently. As a result of the project, the governor issued an Executive Order forming a permanent Public Advisory Committee to continue this type of comparative risk assessment in Louisiana.     

佛山目标产业体系的抉择与逼近──兼论利用外资优化佛山产业结构

分析了区域裂变后的佛山产业体系发展的现状，并结合佛山未来的经济发展战略，勾勒出佛山目标产业体系，同时提出了以外资的利用作为优化佛山产业体系动力源的对策思路。     

国外土地政策研究的新变化

土地是人类赖以生存和发展的物质基础。近二十年来,土地单纯作为自然资源的价值发生了深刻的变化,已成为影响经济和政治活动的重要因素。基于土地的经济和社会价值的与日俱增,土地政策的重要性也越来越受到学者的重视,因此关于土地改革的政策研究也成为热点。     

以公共政策为导向的户外广告规划研究——《深圳市户外广告设置指引》的探索

为了提升城市户外广告环境品质,改进规划工作的不足,提出以公共政策为导向的户外广告规划研究方法。在《深圳市户外广告设置指引》的编制实践中,通过多视角的目标建构、"规范"加"规划"的导控策略以及"手册式"的成果表达手段,取得了良好的实践效果。因此提出:为了提高户外广告规划成果的可操作性,增强实施实效性,必须正确认识户外广告的双重属性,将规划工作从传统的技术导向转变为以公共政策导向,做到导控中的因势"利导"与"力导"。     

榆林能源化工基地产业依存度分析

以2002年陕西省的投入产出表为依据,编制2002年榆林能源化工基地的投入产出表,对2002年榆林能源化工基地的产业依存度状况进行分析;结合2006年榆林统计年鉴编制出2005年榆林能源化工基地的投入产出表,分析2005年榆林能源化工基地的产业依存度状况并与2002年的进行比较。结果表明:能源化工产业各部门之间的依赖关系越来越紧密,各行业对自身的依赖程度在增加,尤其是煤炭开采的独立性增强,与其他产业的关系密切。     

海报设计的竞争优势及发展趋向

海报设计在长达一个多世纪的发展过程中,经历了不断的发展和演变,形成了独特的风格和特点。文章主要分析了海报在当代社会的存在状况以及竞争优势;论述了海报设计作为一种设计艺术形态,在全球一体化的社会环境中蕴涵着个人化、艺术化以及多元化的发展趋势。     

工业经济增长集聚弹性研究——对中国三大经济圈的实证分析

产业集群理论正在继梯度转移理论、增长极发展理论后成为主导区域经济发展新型区域发展理论。在中国的工业化过程中，珠三角、长三角和环渤海地区随着其地区一体化水平的不断提高制造业都表现为不同程度的产业集聚，其制造业集聚程度与地域经济发展特别是工业经济增长都具有较强的相关性。因此，结合面板数据（panel data）模型的计量方法对中国三大经济圈的工业增长集聚弹性进行估计并就三大经济圈的增长集聚弹性差异的成因进行了分析是十分必要的。     

Cox模型和寿险退保研究中的比例危险性

利用生存分析研究寿险退保问题是一个很好的工具，因为可以将寿险保单的持续期（persistency duration）视为生存期长，而将保单的退保或失效看作一个“保单生命”的结束，这其中的保单退保或失效就成为生存研究的目标事件。而导致保单失效的因素会有很多，只有通过利用Cox比例危险模型拟合寿险退保数据以分析影响客户退保的原因，并在对Cox模型的比例危险假设进行检验时，发现部分影响因素并不遵守此前提条件，从而推理得到这些影响因素在不同的时间段对客户退保的影响方式不同。也就是说，其影响有短期效应和长期效应之分。     

A family of estimators of population variance in two-occasion rotation patterns

Abstract

In this article, we have considered the problem of estimation of population variance on current (second) occasion in two occasion successive (rotation) sampling. A class of estimators of population variance has been proposed and its asymptotic properties have been discussed. The proposed class of estimators is compared with the sample variance estimator when there is no matching from the previous occasion and the Singh et al. (2013) estimator. Optimum replacement policy is discussed. It has been shown that the suggested estimator is more efficient than the Singh et al. (2013) estimator and a usual unbiased estimator when there is no matching. An empirical study is carried out in support of the present study.