东北黑土区耕地系统健康诊断及其演化特征——以克山县为例

诊断耕地系统健康状态，揭示耕地系统健康演化过程的时空特征，可为维持和提高耕地系统健康水平提供科学依据。文章以东北黑土区典型地域克山县为研究区，利用突变模型和ArcGIS平台，测算耕地系统健康阈值系数，诊断其健康状态，阐明耕地系统健康演化特征。结果表明：(1)研究区耕地系统健康阈值范围为[0,0.26）、[0.26,0.48）、[0.48,0.71）和[0.71,1.00]4个区间，耕地系统健康状态相应表现为差、中、良和优。(2)1986—2018年研究区耕地系统健康呈现明显的空间分异特征，各乡镇的耕地系统健康在不同时间段存在着健康状态的转化情况。(3)1986—2018年研究区耕地系统健康状况持续下降，耕地系统健康阈值系数下降幅度加快，各乡镇的耕地系统健康阈值系数逐渐趋于均质化，健康阈值系数的差异性持续减小。文章通过构建黑土区典型地域耕地系统健康诊断体系，验证了不同时序耕地系统健康状态差异，提出了建立全生命周期耕地系统健康监测支撑体系的设想，丰富和完善了耕地资源保护和可持续利用的理论与实践。     

黑龙江省八五三农场高标准基本农田建设时序分析

以黑龙江省八五三农场为例,选取耕地田块为评价单元,对研究区耕地的综合质量和农田建设难度进行评价,并在此基础上对研究区高标准基本农田建设时序进行决策,划分为Ⅰ、Ⅱ、Ⅲ期。结果表明:研究区耕地综合质量等级整体较高,受地形地貌的影响而呈现出一定的地域分布规律;农田建设难度则基本以居民点为中心,形成"中心—外围"的圈层空间分布规律;Ⅰ区耕地基本符合高标准基本农田的要求,Ⅱ区是高标准基本农田建设重点区域,Ⅲ区农田基础差、建设难度大。该研究过程和方法可为垦区高标准基本农田建设和乡镇土地整治提供科学参考。     

山东省耕地利用效益的时空差异

文章尝试性地提出耕地利用效益评价指标体系,采用主成分分析、聚类分析和相关分析,并以农业大省山东为例进行实证研究,以揭示区域耕地利用效益的时空差异和特征,为制定提高区域耕地利用效益的对策、为国家制定耕地利用、保护和耕地整理、补偿政策提供参考。研究结果表明,耕地资源利用效益存在着巨大的时空差异;森林覆盖率、人均粮食产量、人力资本水平等8项指标是决定耕地利用综合效益的主要因素。主要结论或政策启示是:政府对耕地的保护政策、补偿政策,不仅要考虑耕地数量,更要考虑耕地利用效益状况,实行高效益高保护、高补偿。     

耕地利用集约度实证研究——以重庆市黔江区为例

耕地集约利用是农业可持续发展的有效途径。耕地集约度的度量是耕地质量评价的最重要的指标。以重庆市黔江区为例,采用耕地投入强度、利用程度、经济指标、社会指标和生态指标等五个方面来构建耕地利用集约度综合评价指标体系,对黔江区耕地集约度及其变化规律进行了研究。     

中国省域农业耕地产出效率实证研究

快速的经济增长导致耕地面积以一种非期望速度被转化为非农用地,无论中国目前是否具备满足日益增长的农产品需求能力,耕地产出效率问题都将成为国内外学者当前甚至未来关注的焦点。通过构建中国农业耕地产出效率评价的DEA模型,以中国31个省（市）为研究对象,进行省域农业耕地产出效率测算,并选取气候条件、农业机械技术、外商直接投资以及教育水平等影响因素与效率值进行回归分析,深层次挖掘中国农业耕地产出效率低下的症结所在,最后,提出相应的改进耕地产出效率的对策措施,以期确保国家粮食安全战略的顺利实施和耕地资源系统的健康发展。     

基于GIS的林口县域耕地地力评价

引言：中国人口众多,人均耕地面积少,农业生产和粮食安女全压力较大。如何利用科技力量,增加单位面积产量,值得研究。通过开展耕地地力评价,为调整种植业布局,实现农业资源的优化配置提供了依据和手段,综合运用GIS的分析、建模和决策等功能[1—2],有效地掌握耕地质量状态,为逐步建立和完善耕地质量的动态监测与预警体系提供支撑。     

耕地细碎化问题研究述评及启示

耕地细碎化问题是制约农业规模经营的主要因素之一,也是农业可持续发展所面临的一项难题。为探讨耕地细碎化问题的研究现状和趋势,文章在参阅国内外文献的基础上从概念、特征、成因、评价方法、影响五个方面对耕地细碎化问题的研究进行了系统回顾,并提出深化耕地细碎化地域性评价方法研究、拓展耕地细碎化影响效应的系统性分析、强化耕地细碎化程度中"度"的测量等今后我国耕地细碎化问题研究的新趋势。     

新疆城镇化与耕地资源协调发展研究

以新疆整体为研究区,借助环境、经济、城市相关专家的理论和研究成果,分析城镇化综合水平与耕地资源的协调发展关系;文章采用综合评价指数、Spearman相关性分析、协调度模型建立以及VAR模型的动态计量等方法揭示新疆城镇化综合水平与耕地资源变动的相关性和协调性。结果表明:2002年-2013年新疆城镇化综合水平与耕地资源呈现正向发展关系,同时运用脉冲响应分析人口城镇化、经济城镇化、社会公共生活、城乡一体化对耕地的影响作用,为新疆城镇化发展与耕地资源的协调发展提供政策建议。     

黑龙江省东部垦区耕地利用效益时空分异特征

耕地利用效益是衡量耕地生产能力和农业可持续发展的重要指标,它具有一定地域的时空分布特征。以黑龙江省东部垦区的宝泉岭、红兴隆、建三江、牡丹江4个农场群为研究区,选取18个具有代表性的指标,构建研究区的耕地利用效益评价指标体系,利用改进的功效系数法和协调度模型,定量计算研究区1999—2008年10年耕地利用经济效益、社会效益、生态效益及其三者的协调度和耕地利用综合效益值,同时运用ArcGIS手段,对1999—2008年研究区耕地利用综合效益特征进行空间分析。结果表明:1999—2008年,研究区耕地利用效益呈现出不稳定的波动状态,且耕地利用综合效益始终受经济效益、社会效益及生态效益三者之间协调度的影响。研究区的耕地利用效益呈现出东北部和中部高、西北部和南部低的明显区域差异性特征。     

基于农户调查的乌鲁木齐市耕地非农化影响因素分析

采用农户问卷调查法对新疆乌鲁木齐市耕地非农化影响因素进行分析研究.分析乌鲁木齐市耕地非农化过程中农户的行为对耕地非农化的影响,以期为新疆制定耕地非农化过程中耕地保护对策提供依据.     

Pleasure and belief in Hume's Decision Process

Abstract

The purpose of this paper is to introduce explicitly pleasure and belief in what aims at being a Humean theory of decision, like the one developed in Diaye and Lapidus (2005a). Although we support the idea that Hume was in some way a hedonist – evidently different from Bentham's or Jevons' way – we lay emphasis less on continuity than on the specific kind of hedonism encountered in Hume's writings (chiefly the Treatise, the second Enquiry, the Dissertation, or some of his Essays). Such hedonism clearly contrasts to its standard modern inheritance, expressed by the relation between preferences and utility.

The reason for such a difference with the usual approach lies in the mental process that Hume puts to the fore in order to explain the way pleasure determines desires and volition. Whereas pleasure is primarily, in Hume's words, an impression of sensation, it takes place in the birth of passions as reflecting an idea of pleasure, whose “force and vivacity” is precisely a “belief”, transferred to the direct passions of desire or volition that come immediately before action. As a result, from a Humean point of view, “belief” deals with decision under risk or uncertainty, as well as with intertemporal decision and indiscrimination problems.

The latter are explored within a formal framework, and it is shown that the relation of pleasure is transformed by belief into a non-empty class of relations of desire, among which at least one is a preorder.     

Globalization,Neoliberalism and the attack on social security

Neoliberal political movements advocate privatization of public pension systems. Globalization imposes pressure on nations to conform to neoliberal policy views with respect to the design and structure of social insurance, including public pension systems. The paper begins with an investigation of the economic, ethical and ideological dimensions of the privatization debates in the U.S.; it argues that privatization advocates may be largely moved by ideology, since the other reasons advanced appear weak or unfounded. The second part discusses the history of Social Security, the purposes for its creation, and some of its economic effects. Differences between public and private pension systems are considered. A brief international comparison of some aspects of public pension system finance and benefit structures is presented. The final section considers the ethical, macroeconomic and distributional implications of privatization, prefunding and payroll tax funding, and argues for a pay as you go system financed with income taxes. In order to promote equity, economic security, community, and social cohesion, public pension systems should be universal in coverage. In order to reduce the inequality, income insecurity, and aged poverty generated by market economies, public pension systems ought to be progressive: benefit/contribution ratios should be inversely proportional to income, and progressive income taxes should finance the system. To promote economic growth, the systems should be financed on a pay-as-you-go basis, and should not be prefunded except for an emergency reserve. The fiscal policy recommendations partially depend upon the theory developed by Abba Lerner in the 1940s, and recently advanced by Wynne Godley and Randy Wray: Lerner's “principle of functional finance.”     

Forecasting the price of gold

This article seeks to evaluate the appropriateness of a variety of existing forecasting techniques (17 methods) at providing accurate and statistically significant forecasts for gold price. We report the results from the nine most competitive techniques. Special consideration is given to the ability of these techniques to provide forecasts which outperforms the random walk (RW) as we noticed that certain multivariate models (which included prices of silver, platinum, palladium and rhodium, besides gold) were also unable to outperform the RW in this case. Interestingly, the results show that none of the forecasting techniques are able to outperform the RW at horizons of 1 and 9 steps ahead, and on average, the exponential smoothing model is seen providing the best forecasts in terms of the lowest root mean squared error over the 24-month forecasting horizons. Moreover, we find that the univariate models used in this article are able to outperform the Bayesian autoregression and Bayesian vector autoregressive models, with exponential smoothing reporting statistically significant results in comparison with the former models, and classical autoregressive and the vector autoregressive models in most cases.     

Planned adaptation in risk regulation: An initial survey of US environmental, health, and safety regulation

In principle, we want regulatory programs to be based on current realities, as reflected for example in the best knowledge of relevant experts. That would imply that old rules now on the books should be consistent with today's knowledge base, not just what was known when a rule or standard was originally set. This paper reports on a survey of US programs, examining how often existing rules are actually updated in light of better knowledge, and identifies five programs that attempt to make policy routinely adaptive. These programs exhibit what we term Planned Adaptation: they both revise rules when relevant new knowledge appears, and take steps to produce such improved knowledge. While Planned Adaptation is rare, it is used in several nationally prominent programs, including air pollution, airplane safety, and drug safety. Planned Adaptation is a policy tool that deserves more attention.     

The greenhouse effect: Damages,costs and abatement

The buildup of so-called greenhouse gases in the atmosphere — CO₂ in particular-appears to be having an adverse impact on the global climate. This paper briefly reviews current expectations with regard to physical and biological effects, their potential costs to society, and likely costs of abatement. For a worst case scenario it is impossible to assess, in economic terms, the full range of possible non-linear synergistic effects. In the most favorable (although not necessarily likely) case (of slow-paced climate change), however, it seems likely that the impacts are within the affordable range, at least in the industrialized countries of the world. In the third world the notion of affordability is of doubtful relevance, making the problem of quantitative evaluation almost impossible. We tentatively assess the lower limit of quantifiable climate-induced damages at $30 to $35 per ton of CO₂ equivalent, worldwide, with the major damages being concentrated in regions most adversely affected by sea-level rise. The non-quantifiable environmental damages are also significant and should by no means be disregarded.The costs and benefits of (1) reducing CFC use and (2) reducing fossil fuel consumption, as a means of abatement, are considered in some detail. This strategy has remarkably high indirect benefits in terms of reduced air pollution damage and even direct cost savings to consumers. The indirect benefits of reduced air pollution and its associated health and environmental effects from fossil-fuel combustion in the industrialized countries range from $20 to $60 per ton of CO₂ eliminated. In addition, there is good evidence that modest (e.g. 25%) reductions in CO₂ emissions may be achievable by the U.S. (and, by implication, for other countries) by a combination of increased energy efficiency and restructuring that would permit simultaneous direct economic benefits (savings) to energy consumers of the order of $50 per ton of CO₂ saved. A higher level of overall emissions reduction — possibly approaching 50% — could probably be achieved, at little or not net cost, by taking advantage of these savings.We suggest the use of taxes on fossil fuel extraction (or a carbon tax) as a reasonable way of inducing the structural changes that would be required to achieve significant reduction in energy use and CO₂ emissions. To minimize the economic burden (and create a political constituency in support of the approach) we suggest the substitution of resource-based taxes in general for other types of taxes (on labor, income, real estate, or trade) that are now the main sources of government revenue. While it is conceded that it would be difficult to calculate the optimal tax on extractive resources, we do not think this is a necessary prerequisite to policy-making. In fact, we note that the existing tax system has never been optimized according to theoretical principles, and is far from optimal by any reasonable criteria.During the academic year 1989–90 Dr. Ayres was at the International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.During the summer of 1989 Mr. Walter was a member of the Young Scientists' Summer Program at IIASA.     

Interest on reserves and inflation

The payment of interest on reserves has been a common practice in inflationary economies. This policy may seem paradoxical since it involves returning part of the seigniorage, generated by the inflation process, with the intention to finance the fiscal deficit. This paper argues that the motivation for this policy can be captured by the discretionary regime, where the policymaker pays interest on reserves because he is concerned with the erosion of real liquidity by inflation, which is in part beyond his control. However, this policy is an unlikely outcome in the commitment regime, where the policymaker is in full control of inflation.     

SCIENCE AND INDUSTRY: TRACING THE FLOW OF BASIC RESEARCH THROUGH MANUFACTURING AND TRADE

This paper describes flows of basic research through the US economy during the late 20th century. In addition, the paper studies the effect of the flows on scientific papers in industries and fields. This article differs from others in its use of measures of science rather than technology. Together, its results present a picture of the structure of basic research flows in a modern, science-intensive economy. Basic research flows are large within petrochemicals and drugs, and within software and communications. Flows of chemistry, physics, and engineering are common throughout all industries – biology and medicine are almost confined to petrochemicals and drugs; and computer science is nearly as restricted to software and communications. In general, basic research flows are more concentrated within scientific fields than within industries. Our findings concerning the production of scientific papers indicate that the effect of a 1% change in academic R&D spillovers significantly exceeds that of industrial spillovers. In addition, within-field effects exceed effects between-fields, while within- and between-industry effects are roughly equal. It follows that scientific fields limit basic research flows more than industries do, perhaps because large firms implicitly span a range of industries.     

Bayesian estimation of duration models: An application of the multiperiod probit model

The multiperiod probit model is presented and Bayesian estimation using the Gibbs sampler with data augmentation is described. As an empirical illustration, the multiperiod probit model is then used to estimate a duration model using employment duration data for the Canadian province of New Brunswick. Bayesian estimation with unobserved heterogeneity is shown to be a simple extension of estimation of a duration model with no unobserved heterogeneity. More importantly, perhaps, some numerical problems encountered by other authors using Maximum Likelihood are avoided.I would like to thank M. Baker, G. Koop, A. Melino and D. Poirier for helpful comments and discussions. I would also like to thank M. Baker for providing his data.     

Scenarios and creativity: Thinking in new boxes

To be creative and make change happen, leaders must do more than simply ‘think outside the box’, as the traditional business manuals suggest, using the popular American expression. After all, the space outside the box is infinitely expansive. Moreover, there can be no guarantee that a solution to the problem will be found. The answer: ‘Think in new boxes.’ This requires developing the right new box; in other words, useful new models, a helpful new approach to a problem. That is the real art of practical creativity. This short article outlines the approach (Thinking in New Boxes) and its application to classic scenario planning with a few examples. The authors also present the ‘Expressway to Scenarios’, an approach that wins in impact and practicality what it loses in deep analysis, by having top executives involved in key steps.     

Valuing Mangrove-Fishery Linkages – A Case Study of Campeche, Mexico

This paper explores the value of mangrove systems as a breeding and nursery habitat for off-shore fisheries, focusing on mangrove-shrimp production linkages in Campeche State, Mexico. We develop an open access fishery model to account explicitly for the effect of mangrove area on carrying capacity and thus production. From the long-run equilibrium conditions of the model we are able to establish the key parameters determining the comparative static effects of a change in mangrove area on this equilibrium. We then estimate empirically the effects of changes in mangrove area in the Laguna de Terminos on the production and value of shrimp harvests in Campeche over 1980–90. Our findings suggest that mangroves are an important and essential input into the Campeche shrimp fishery, but that the low levels of deforestation between 1980 and 1990 mean that the resulting losses to the shrimp fishery are still comparatively small. Over-exploitation of the fishery due to open access conditions remains the more pervasive threat, and without better management any long-run benefits of protecting mangrove habitat are likely to be dissipated.