中国粮食生产区域特征与成因研究——市场化改革以来的实证分析

中国各省区粮食产量占全国粮食总产的比例的动态计算和统计分析表明 ,市场化改革以来 ,中国粮食生产具有稳定的区域变化特征。计量检验显示 ,农村人均耕地资源与非农产业就业拉力是中国粮食生产区域特征的重要影响因素。本研究提示 ,中国粮食生产区域特征具有持久性 ,它对区域粮食政策和省区际粮食贸易将产生深远影响。     

中国粮食生产区域分化特征和成因的实证研究

对中国在1990年和2002年粮食生产的区域分化状况进行统计分析的结果表明,工业化和城市化的发展,以及农产品市场形成条件下,稻米生产的区域分散特征、小麦生产的区域集中特征以及玉米播种面积的集中和生产产量的分散特征日益明显。计量检验显示,人均承包经营耕地面积和种植业收入比率是影响粮食生产区域分化的最主要的两个因素。     

中国水稻生产空间布局变迁及影响因素分析

基于1978--2009年中国各地区（省、市、区）水稻生产面板数据,运用区域重心分析法测定并描绘中国水稻生产空间布局变迁轨迹,应用空间计量经济学方法实证分析水稻生产空间布局变迁影响因素。研究表明,中国水稻生产存在显著的正向空间效应,由南向北变动轨迹十分明显,水稻生产空间布局变化与农业劳动力、化肥施用量、有效灌溉面积、水稻单产和耕地面积呈显著正相关,与非农就业机会呈显著负相关。     

中国粮食生产空间布局变迁的特征分析

基于31个省市区粮食和3种主要粮食作物的产量数据,运用描述性统计分析、GIS、空间自相关分析等方法系统刻画了1978-2010年中国粮食生产空间布局的时空特征.结果表明:粮食产区逐渐向东北和中部集中;南方稻谷优势区域继续稳固的同时东北稻谷重要性逐渐凸显;小麦产区逐渐向北方和中部集中;玉米产区逐渐向东北、华北和华中集中;粮食、稻谷和玉米的重心向东北移动251.20km 、286.45km和106.14km,但小麦重心移动方向不明显且距离也较短;粮食及稻谷、小麦、玉米生产均存在显著空间相关性,其中粮食、小麦、玉米生产空间集聚效应增强,稻谷生产空间集聚效应减弱.     

新世纪中国粮食生产特征及粮食安全政策取向

全球疫情持续和俄乌冲突以来，确保大宗商品供应链稳定，消弭全球粮食供应不确定性因素，成为全球经济安澜的重要基础。本文基于国家统计局根据第三次农业普查后发布的修正数据，对新世纪以来中国粮食生产的阶段特征、品种特征和区域特征进行了深入分析，并对其因素贡献进行了解释。结果表明，新世纪以来中国粮食播种面积扩大、单产水平提高在不同阶段交互作用推动中国粮食产量实现“十九连丰”,中央政府连续出台的系列粮食生产扶持政策发挥了显著制度效应。运用跨学科和结构分析方法，对新时期中国粮食生产结构演化的主要挑战进行了分析。在此基础上提出新时期中国粮食安全的政策取向，包括优化粮食生产区域布局，实施藏粮于地、藏粮于技战略，优化制度支持体系和建立主产区与主销区间的利益补偿机制等方面。     

外资主导下的汽车制造业空间分布特征及其影响因素——以广州为例

以1 069家广州汽车及零部件制造业企业为研究对象,采用GIS和HDBSCAN空间聚类方法分析其空间布局变化及特征,并采用负二项回归模型定量分析影响汽车制造业企业分布的因素,研究发现:(1)广州汽车制造业企业空间集聚特征显著,空间布局演变由近郊区往外围区域扩张;(2)由于长期过于依赖外资整车企业,导致广州汽车制造业产业链存在过于封闭的特征,对汽车零部件企业的辐射带动效应不足;(3)外资和内资汽车零部件企业在空间布局上存在明显差异,外资企业偏向围绕外资整车企业布局,而内资企业偏向沿交通干线布局;(4)广汽传祺、广汽客车等中国品牌对广州汽车零部件企业更具有辐射带动效应,有利于推动技术创新;(5)负二项回归模型显示整车带动、区位因素、集聚经济、人口密度等因素对汽车制造业企业空间布局有重要影响,而交通因素对广州汽车制造业企业布局影响不显著。     

中国县域粮食产量时空演变及影响因素变化

基于2000—2014年中国县域粮食产量和社会经济指标数据,综合运用标准差椭圆、空间自相关分析和地理探测器等方法,分析了近15年来不同区域粮食产量变化特征,并探讨了中国县域粮食生产格局的空间演变、分异特征及影响作用机制。研究结果表明:(1)近15年来全国粮食生产整体呈上升趋势,2004—2013年出现了粮食产量"十连增"现象,全国粮食产量平均年增长率为2.43%;粮食产量变化具有地形分异规律,九大农区中粮食产量比重较高的农区分别为黄淮海农业区、长江中下游农业区、东北农业区。(2)全国粮食高产县数量增加,粮食生产重心逐渐向东北偏移;粮食生产分布格局仍符合胡焕庸线分布特征,但西北部粮食高产区范围有所扩大。全国粮食增产和减产区呈现明显的空间集聚状态,且集聚状态不断加强,高高集聚区逐渐向东北农业区偏移,低低集聚区逐渐向东部和南部沿海偏移,中国粮食生产的地域分工更加清晰。(3)2000—2014年,影响全国范围内粮食产量分布的主要因素由人口和第一产业增加值转变为耕地面积和农业机械总动力,不同因素对粮食产量空间分布的作用机制存在差异。     

增强我国粮食安全的综合保障能力对策

虽然2004年以来我国实现了粮食生产的"九连增",但受多重因素的影响,我国粮食安全呈现新的特征,并面临严峻的挑战,提高国家粮食安全的综合保障能力势在必行。必须从国民经济全局和国家战略高度出发,调整现有工业化、城镇化资源与空间布局战略,把确保国家粮食安全放在现代化建设的重要位置;加强农业基础设施建设;增强粮食流通能力;提高粮油食品质量安全水平;建立健全粮食生产科技支撑体系;增强农业抗灾减灾应变能力;加强粮食宏观调控能力建设;统筹国内国际两个市场;出台《粮食法》,依法治粮。     

中国玉米生产布局的变迁分析

基于空间计量的研究视角,运用全域Moran’s I指数考察1985—2012年中国省际玉米生产的空间相关性,并构建空间杜宾模型,分析中国玉米生产布局变化的影响因素。研究结果表明,中国玉米生产布局存在显著的正向空间相关性,生产重心北移明显;玉米与替代农作物亩均净收益差值、农业技术、畜牧业发展、交通运输与政策对本区域玉米播种面积扩大有正向影响,其中技术和政策的空间溢出效应显著;非农收入对玉米生产布局扩大的消极影响主要作用在邻接省份。各影响因素效应的局部性特征致使中国玉米生产布局发生变化。政府部门需要重视我国省域间玉米生产空间关联性,制定差异化的玉米产业扶持政策,协调跨区域粮食调配,确保粮食区域间的供需平衡,保障国家粮食安全。     

中国粮食生产的影响因素分析及政策建议

本文用中国1985-2008年间的粮食生产相关投入要素数据,通过逐步回归和加权最小二乘回归等经典单方程计量经济学方法,构建了一个统计特征合理的中国粮食生产函数.通过对模型的分析发现影响粮食生产的最主要因素,并提出了一些政策建议.     

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.     

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.     

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.     

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.     

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.”     

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.     

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.     

An Economic Analysis and Simulation of Woodfuel Management in the Sahel

This paper presents an economic framework and a computationalmethodology for assessing the evolution of woodfuel supply costsand the spatial distribution of biomass in a Sahelian woodlandsetting. Spatial data on standing stock and the costs oftransport to market are used to construct a supply curve for fuelto a fuel-consuming location. Given an exogenously specifieddemand, the model simulates, period by period, the extraction,regeneration, and transport of wood fuels. The model is appliedto evaluate the benefits and ecological impacts of scenarios forwoodland management around the city of N'Djamena, Chad.