Renewable Resources in an Overlapping Generations Economy Without Capital

We incorporate a renewable resource into an overlapping generations model without capital and with quasi-linear preferences. Besides being an input for production the resource serves as a store of value. We characterize the dynamics, efficiency, and stability of the steady-state equilibria. The stability properties are sensitive to the type of resource growth. For constant growth there is only one steady-state equilibrium which is stable and efficient. In the general case of the concave growth function, there are usually at least two steady-state equilibria, one of which is stable and the other one unstable. The unstable steady state is efficient, but the stable one may or may not be. We study the robustness of our results by assuming a logarithmic utility function. We show that for the Cobb–Douglas production function the steady state is unique and stable regardless of whether the equilibrium is efficient or inefficient. Our analytical results are illustrated by numerical calculations.     

Sustainability: a Dissent

Abstract:  Broadly conceived and considered in its many usages, sustainability has grave defects as a planning goal, particularly when used by conservationists: it confuses means and ends; it is vague about what is being sustained and who or what is doing the sustaining; it is uninspiring; it is little more than Pinchot-era conservation (and thus ignores the many lessons learned since then); it need not be linked to land, to the land's functioning, or to any ecological science; it need not include a moral component; it is consistent with the view of humans as all-powerful manipulators of the planet; and, in general, it is such a malleable term that its popularity provides only a facade of consensus. When sustainability is defined broadly to include the full range of economic and social aspirations, it poses the particular risk that ecological and biodiversity concerns will be cast aside in favor of more pressing human wants. Given these many defects, the conservation movement should discard the term in favor of a more alluring goal, attentive to nature and its ecological functioning. A sound goal would incorporate and distill the considerable ecological and moral wisdom accumulated since Pinchot's day while giving conservationists the rhetorical tools needed to defend the land against competing pressures. In our view, conservation would be well served by an updated variant of "land health," Aldo Leopold's ecologically grounded goal from the 1940s. Land health as an independent understanding should set the essential terms of how we live and enjoy the earth, providing the framework within which we pursue our many social and economic aims.     

全球环境问题与当代国际关系

环境问题使人类面临着前所未有的生存与发展的巨大挑战，也深刻影响着当代国际关系的发展和演变。该文对环境问题引起的国家安全，全球环境问题的南北分歧，以及南北矛盾的焦点等几个方面，分别进行了阐述和分析，随着环境总是的国际化和全球化，国际社会把保护环境看成是各国政府的共同义务和责任，而与此同时国际间的环境合与竞争关系也得到了进一步的发展。     

对产生环境问题的根源探析

从多维、多学科的视角，就环境问题产生的原因进行了比较系统，全面的研究和探讨。具体包括环境问题产生的哲学根源、宗教根源、伦理根源、技术根源和经济根源。从表面上看，环境问题是一个技术问题、经济问题；但从深层次考察，环境问题则也是哲学问题、宗教问题和伦理问题。环境问题的根本解决，不仅有赖于技术进步和经济法律制度的变革，更有赖于人类文明的转型和伦理观念的觉悟。     

Influence of conservation tillage on winter bird use of arable fields in Hungary

Bird use of conservation tillage-established (CT—seedbed preparation without soil inversion) crops was assessed at two adjacent sites in western Hungary, in comparison with conventionally established (mouldboard ploughed—P) fields. Bird abundance was assessed in a typical rotation of spring-sown maize and winter wheat in three consecutive winters. In the first winter, several species and the guild of seed-eating passerines were significantly more abundant on CT established plots, in both crop types. In the second winter, only starlings were more abundant on CT plots. In the third winter, only skylarks favoured CT over P plots. In combination with agri-environment scheme measures designed to provide resources for biodiversity, conservation tillage could play a role in softening the impact of agriculture on farmland birds in Hungary and elsewhere in Eastern Europe, in addition to its potential for reducing soil erosion and diffuse pollution.     

建材资源开发的生态环境补偿费探讨

应用新的资源价值观念与环境经济学中ＭＯＣ框架及其它理论，给出了建材资源的生态环境补偿费的定义与确定方法，建立了相应的理论模型。在此基础上，根据不同地区的经济发展水平与环境现状等实现情况，用认可系数对计算的补偿费进行修正。     

人工神经网络模型和公路复垦土地适宜性评价

提出了人工神经网络用于公路临时用地复垦土地适宜性评价，利用该模型对京大高速公路山西段复垦山西段复垦土地进行了适宜性评价，探讨了人工神经网络在土地复垦适宜性评价时的特点和注意问题。     

西藏食物保障的自然资源相对优势分析

对西藏食物保障的自然资源相对优势研究表明 ,光能、生物、旅游资源是西藏食物保障的突出相对优势。这些资源具有独特、再生和易于持续开发利用等突出特点 ;水利资源和矿产资源具有明显的开发利用优势 ,但是 ,与经济落后形成了极大的反差 ,目前开发乏力 ,开发利用将带来后续管理与环境保护的沉重负担 ;耕地、草地与森林资源既具有明显的优势 ,又有突出的劣势 ,主要表现为数量的优势与质量的劣势。西藏未来食物保障 ,取决于如何将这些资源的相对优势有效组合、综合管理和合理开发利用。     

区域土地可持续利用与环境政策-体化

可持续发展应分阶段、分层次地进行，为增强区域土地可持续利用，相关环境政策的制定遵循可持续发展的原则，提出了区域土地可持续利用的评价流程与环境政策形成的循环模式；介绍了国外区域开发环境影响评价的研究进展及区域环境管理规划的主要内容；分析了这一领域的相关法律问题并提出了建议。     

黄冈市矿业经济布局研究

文章针对黄冈市矿业经济发展的需要，在充分考虑黄冈市地区经济发展，矿产资源分布，矿业经济合理布局的必要性的基础上，对黄冈市矿业经济布局作了详细深入研究，提出了“一个中心，四个矿业规划区，五类开发矿种，十个矿业基地”的布局构架，为该市矿业经济发展提供了明确的发展思路，并指出了发展重点，也为政府宏观调控和矿政管理提供了依据。