Food–oil volatility spillovers and the impact of distinct biofuel policies on price uncertainties on feedstock markets

Over recent decades, the link between crude oil and agricultural markets has been reinforced following the introduction of biofuels. We use timely measures of (co)variation spillovers to analyze the role of crude oil in shaping price uncertainties of agricultural commodities, which are largely used as biofuel feedstocks. Our sectoral- and market-specific measures distinguish tranquil (1995–2005) and crisis episodes (2006–2015), as well as periods during which either consumption mandates or tax credits were enacted to spur biofuels. During the crisis period, crude oil volatility transmissions account for 16% (20%) of price uncertainties in ethanol (biodiesel) feedstock markets on average. Moreover, we find evidence of enhanced volatility transmissions under tax credit regimes compared with consumption mandates. The results from pooled regressions confirm stronger volatility transmissions by about 12% under the enactment of tax credits.     

On the economics of forests and climate change: Deriving optimal policies

First-best optimal forest sector carbon policy is examined. Using a forest and energy sector model with a carbon cycle module we show that the renewability and carbon neutrality arguments do not warrant emission free status of wood use. As a general optimality principle, the release of carbon is penalized by a tax and carbon capture is subsidized. However, under the biomass stock change carbon accounting convention, the land owners pay for the roundwood emissions and, to avoid double counting, the use of roundwood is treated as emission free. Yet, the carbon accounting convention followed does not affect the equilibrium outcome. The bioenergy from harvest residues is not emission free either. Furthermore, we show that an optimal policy subsidizes the production of wood products for their carbon sequestration. Correspondingly, carbon removals by biomass growth are subsidized and the harvest residue generation taxed. Numerical solution of the model shows that, although the use of wood is not emission free, it is optimal to increase the use of wood, possibly also in the energy sector. Before the wood use can be increased, the forest biomass will be increased. This carbon sink decreases the net emissions until the forest resources reach a new equilibrium.     

Land use and economic effects of alternative biofuel policies in Brazil and the United States

Being the two largest ethanol producers in the world, biofuel policies in Brazil and the United States affect both their domestic markets and the global food and biofuel economy. In this article we develop a price endogenous mathematical programming model to simulate and analyze the impacts of biofuel mandates and trade distortions on land use, agricultural commodity and transportation fuel markets, and global environment. We find that an 80% increase in total biofuel production from its 103 billion liter baseline level to the mandated 183 billion liter level in 2022 can be achieved with less than 2% increase in total cropland use in both countries. In the United States, this would occur with cellulosic biofuels meeting nearly half of the biofuels consumed and produced largely on cropland pasture and corn ethanol meeting the rest of the mandate and resulting in a 2% increase in corn price. In Brazil, the expansion in sugarcane production would be achieved by reducing land under pasture and a marginal increase in intensification of livestock production. In the aggregate, biofuel policies increase economic surplus in both countries by 1% and redistribute the benefits from agricultural consumers to agricultural producers and the fuel sector. Finally, we also find that full implementation of the mandates in North America, China, and the European Union would reduce the global life‐cycle global greenhouse gas emissions by about 5%.     

黄土丘陵区水土流失的环境经济学分析

在对国内外生态破坏经济损失研究概况综述的基础上，以黄土丘陵区宁夏固原县为例，分别将水土流失造成的养分损失、水分损失和其它直接经济损失货币化，就水土流失对区域外的正、负外部性总量进行衡量；探讨了区域外部性的解决途径。     

Empirical evaluation of nonpoint pollution policies under agent heterogeneity: regulating intensive dairy production in the Waikato region of New Zealand*

Models used for policy evaluation rarely consider firm heterogeneity, despite its importance for instrument design. This study considers agent heterogeneity explicitly in the evaluation of policies for nonpoint pollution control through the integration of decomposition and calibration procedures for programming models. The application concerns the regulation of nitrate leaching from intensive dairy production in the Waikato region of New Zealand. Failing to represent firm heterogeneity leads to widely different estimates of mitigation costs, relative to where heterogeneity is considered. Variation in baseline emissions and the slopes of abatement cost curves between firms renders a differentiated policy less costly than a uniform standard. However, the relative values of these policies are not broadly different, as firms required to do the most abatement – intensive farms with large baseline pollutant loads – can do so more cheaply, on average.     

水污染对土壤动物群落结构的影响

以芜湖市经济技术开发区为例,通过对比的方法。对5种不同水污染所造成的土壤动物群落结构的变化进行了取样调查,在5种生境中共取10个样方,获得土壤动物1333个。其中优势类群为螨、弹尾、蚯蚓和线蚓;由于水污染源的不同,各生境土壤动物的种类和教量也随之发生变化,土壤动物群落的多样性、均匀性、优势度几个重要指标存在很大差异。垂直分布出现逆分布现象。     

南充市清洁能源行动计划的政策分析

分析了南充市区大气污染的主要原因是排放污染物(TSP和SO2)较大的工业锅炉和民用燃煤设施。清洁能源行动是治理南充市区大气污染的可行性方案,研究表明,1997-2003年南充市区大气质量明显提高。预测2005年可以达到国家空气质量二级标准。清洁能源行动过程中面临经济、管理和法规等方面的政策障碍,提出通过市场调节机制克服并完善,实现市区大气质量的持续改善。     

On the economics of agricultural production*

Agriculture is in the business of using ecosystem services to produce food. Examining how agro‐ecosystems function provides useful insights into the economics of agriculture. Of special interest are the presence and nature of scale effects, complementarity effects and convexity effects in ecosystem functioning. Implications for agricultural productivity and the economics of agriculture are evaluated. At the farm level, this helps to better understand the current trend toward greater specialisation. Current challenges for agricultural contracts, markets and policy are explored.     

哈丁定律与渔业资源养护与管理探讨

论文论述了海洋生物资源是典型的“公地资源”.建立科学的、可持续的海洋生物资源养护与管理制度是解决当前海洋渔业资源面临问题的必要措施.笔者认为,渔业资源管理制度的核心内容包括渔业资源产权制度、利用渔业资源的准入制度和渔业合作机制.明确渔业资源的产权定位;摒弃自由捕捞的传统观念,建立利用渔业资源的准入制度,并在此基础上逐步建立区域渔业合作机制,变非理性博弈为合作共赢.这些制度和措施是解决海洋渔业资源“公地悲剧”和资源衰退的有效的途径.     

水产经济学若干基本概念之研究

近些年,水产经济研究发展比较迅速,但是学界和业界很多人对水产经济学基本概念的理解和区分不是非常清晰,导致相关研究和交流出现概念混淆不清、众口众词的现象.本文作者在参考大量相关资料及多年研究的基础上,对"渔业"与"水产业"、"渔业经济学"和"水产经济学"、"渔民"和‘‘渔村居民"等非全同概念进行了辨析,对"渔村"、"渔业生产结构"等模糊含混概念进行了界定,并引入"养殖努力量"、"渔业努力量"两个新概念.通过理清水产经济学基本概念,以期对以后的相关研究和交流提供一些有益的借鉴.     

长期不同施肥处理对黑土不同组分有机碳的影响

以吉林省农业科学院土壤肥料研究所"国家黑土肥力与肥料效益长期定位监测基地"土样为材料,对长期施肥条件下不同施肥处理土壤有机碳、活性有机碳和颗粒有机碳进行了研究。结果表明:有机肥配施化肥有利于提高黑土有机碳含量,长期不同施肥处理对土壤水溶性有机碳和微生物量碳的影响差异显著,高量有机肥与化肥配施处理含量最高,长期施用化肥降低了土壤颗粒有机碳含量,有机肥的施用可以显著提高黑土有机碳含量。     

Impacts of foreign policies on the gains from research and promotion

This paper compares llie direct and indirect effects of rest-of-the-world (ROW) policy on welfare in country A: the direct effect due to the change in world price caused by (he policy in (he absence of research/promotion-induced shifts in supply/demand, and the additional (or indirect) effect of the policy on (he welfare gain to country A from its investment in research and promotion. The results showed that the reduction in aggregate economic benefits from research/promotion due to a world price-reducing policy in ROW could be in the range of 25-50% of the direct reduction in social welfare due to the ROW policy. In the case of Australian beef/veal, it is possible for the welfare impact of the ROW policy via research payoff in country A to exceed the direct welfare cost.     

Production economics in the presence of risk*

This paper provides an overview of the literature on production under the influence of risk. Various specifications of stochastic production function such as models with additive and multiplicative uncertainty, Just and Pope model, output‐cubical, state‐allocable and state‐general models are discussed. Further, criteria determining optimal producer behaviour are derived for deterministic production technology and for various kinds of state‐contingent technologies such as output‐cubical, state‐specific, state‐allocable and state‐general technologies. Finally, a brief discussion is presented about the drawbacks of each of these specifications of technology.     

改革开放三十年我国水产业发展的政策回顾

改革开放三十年,我国水产业发展迅速,在世界上占有举足轻重的地位.水产业的发展得益于我国改革开放后中央领导对水产工作的高度重视,本文首先简要描述了我国水产品产量情况及在世界上的地位,然后回顾水产养殖业改革开放三十年的发展历程, 在此基础上,分析了改革开放以来,党中央领导对水产工作所做出的政策文件批示,指出了水产业的大发展得益于改革开放.     

Impact of conservation agriculture technology on household welfare in Zambia

This article examines the determinants and impact of conservation agriculture (CA) technology adoption on farm household welfare in Zambia. To account for selection bias from both observable and unobservable factors, an endogenous switching regression model is employed to estimate the impact of the technology on continuous outcomes like farm output, throughput accounting ratio (TAR), poverty gap, and severity of poverty. A recursive bivariate probit model is however used for the estimation of impact of adoption on a binary outcome like poverty headcount. The empirical findings demonstrate that the adoption of CA technology increases maize output, and farm TAR and reduces household poverty. Moreover, the results reveal that farmers’ years of schooling, social networks, access to credit, extension services, and machinery as well as soil quality positively influence adoption of CA technology.     

浅谈税收优惠政策的运用

税收优惠政策是有效实施宏观和微观调控的重要税收杠杆。当前的税收优惠政策在总体上应调整为坚持产业优惠为主、区域优惠为辅的目标,区分税种实行多种形式优惠,并根据我国目前税收优惠的具体情况,完善立法,尽快使税收优惠走向法治化轨道。同时要加大对“地方土政策”清理力度,保证税收优惠政策公正、公平、公开。从而使国家一定时期的税收优惠政策能真正起到促进经济和社会迅速发展的积极调控作用。     

Evaluating the impact of government land use policies on tree canopy coverage

Many cities around the world are experiencing the negative effects associated with not sustaining a sufficient level of tree canopy coverage. Tree canopy provides environmental benefits such as clean water and air, erosion prevention, climate control, and native species habitat and provides economic benefits such as higher housing values and lower energy expenditures. We study local government policies in a large U.S. metropolitan area (the Atlanta Metropolitan Statistical Area) to find which policies perform the best at preserving or increasing urban forests. Empirical analysis reveals that a set of effective tree ordinance clauses, zoning ordinances, and having high quality smart growth projects in the community all help in preserving tree canopy in economically and environmentally meaningful amounts. Other actions, such as simply having a tree ordinance, designating a key management person in charge of tree programs, the presence of a tree board, and multiple communication channels were shown to be ineffective for our data set. Because benefits from tree canopy accrue to the local government's budget, to residents and to business owners, the entire community should gain from the passage of effective policies to preserve their local tree canopy. Estimated economic benefits from preserving tree canopy through an effective set of public policies are in the range of $10–15 million annually in an average county, mostly due to savings on stormwater management.