Effects of scale economies and production seasonality on optimal hub locations: the case of regional fresh produce aggregation

Interest in supporting local and regional food systems is rising and food hubs have attracted considerable attention among Federal, State, and local policymakers. This study explores the problem of endogenous hub location in fresh produce value chains in the Northeastern United States. To overcome limitations in the literature, we incorporate the effects of economies of scale and production seasonality into our models. Three experimental models are designed to examine the effects of alternatively applying yearly, quarterly, and monthly data on model solutions. We explicitly assess how interactions of scale economies and seasonality influence the structure and spatial attributes of an optimal regional produce aggregation hub system. The three models generate marketed different solutions and in many respects they lead to different conclusions about developing local/regional supply chains. The monthly model allows for production seasonality and actual hub operation cycle frequency and thus leads to more efficient hub solution with rich policy implications.     

集体建设用地市场化进程：现实选择与理论思考

研究目的:现有文献对集体建设用地市场化改革的现实模式选择和路径演化归纳还相对薄弱。本文旨在基于观察不同类型集体建设用地(包括宅基地、经营性建设用地、公共基础设施用地以及征地)的市场化改革典型路径的基础上,探索不同模式在提升建设用地经济效率上殊途同归的共性规律,为城乡统一建设用地市场提供理论支撑。研究方法:案例分析与比较研究。研究结果:总结了本轮集体建用地市场化改革起点,刻画了宅基地、征地、统筹和入市4类市场化的典型模式或特殊现象,并对集体建设用地市场化规律做了初步探索。研究结论:集体建设用地市场化的现实路径是渐进式的"由点及面"的改革,现阶段改革创新需要关注三类收益分配问题,政府的规划和收益调节政策是地方探索市场化亟需的基础性规则,政府还应尽快对市场化中的各项权利开展立法工作。     

农户土地转出的影响因素研究*——基于土地流转补贴政策效用的视角

[目的]基于安徽省蚌埠市的调研数据,实证研究土地流转补贴政策对土地转出的影响,分析土地流转补贴政策效用。[方法]文章根据国内外相关研究成果,结合调研地区的具体环境因素,提出研究假设,选取农户的家庭人口特征、社会经济特征和土地资源禀赋等变量,构建回归模型,运用SPSS统计软件分析农户土地转出的影响因素及土地流转补贴政策的效用。[结果]直接影响农户土地转出的因素包括非农就业、非农收入、农民离乡进城务工条件和土地资源禀赋等,农民获得的土地流转补贴占家庭总收入的比重非常小,对农户转出土地的意愿起不到显著促进作用。[结论]因此,促进土地有序流转必须把土地流转补贴等财政扶持资金转移到基本生产设施的建设上,改善农业生产经营条件,增强新型农业经营主体的土地转入积极性;通过创造非农就业机会,增加非农收入,完善农村社会保障服务体系,促进农民工市民化等措施,弱化农民对土地的依赖,从而增强农民转出土地的积极性。     

A Meta‐Analysis on the Elasticity of Demand for Pesticides

There is an increasing policy interest in pesticide taxation schemes as a measure to reduce harmful effects of pesticide use. The effectiveness of such tax depends, however, on the price elasticity of demand for pesticides. Moreover, information on these demand elasticities and their determinants is of crucial relevance for policy‐making and normative modeling approaches. In this article, we present a meta‐analysis based on studies that have estimated pesticide demand elasticities in Europe and North America. Our meta‐analysis reveals that the own‐price elasticities of demand for pesticides are, with a median of ?0.28, significantly smaller than zero, but also significantly larger than ?1, i.e. to be inelastic. We find that the demand for pesticides for special crops is less elastic than that for arable and grassland. In addition, the demand for herbicides is more elastic than for other pesticides. Studies that consider only short‐term horizons and little flexibility for farmers to adjust to price changes generate significantly less elastic pesticide demands. The results also indicate that more recent studies identify lower pesticide price elasticities of demand. Furthermore, we find that peer‐reviewed studies tend to find more inelastic results compared to grey literature.     

Motivations to grow energy crops: the role of crop and contract attributes

Perennial energy crops are a promising source of bioenergy whose production involves production risks, long‐term commitment of land and need for crop‐specific investments without the coverage of crop insurance potentially available for conventional crops. We conduct a choice experiment in five states in the Midwestern and South‐central regions of the U.S. to examine the effect of crop‐contract attributes on the joint discrete‐continuous choice decisions to adopt an energy crop and convert acres to it from a status quo use, while controlling for the effect of various farmers’ risk and time preferences, sociodemographic characteristics, and availability of crop insurance for conventional crops. We find robust evidence that high discount rates, high upfront establishment costs and need for crop‐specific investments create disincentives for adoption and allocation of land to energy crop production. The effects of riskiness of returns and risk aversion are less robust across specifications. The effect of conventional crop insurance on the energy crop adoption decision differs across types of insurance; in particular, farmers with revenue insurance are statistically significantly less likely to adopt an energy crop. Our results have implications for the design of effective contracts and policy incentives to induce the production of energy crops.     

Erosion mitigation in the Waikato District,New Zealand: economic implications for agriculture

Soil erosion, in its various forms, is caused or aggravated by agricultural activities. Mitigation of surface erosion comprises the construction of shelterbelts, fencing, riparian buffering, and stock reduction. Mitigation of mass‐movement erosion, in turn, takes the form of spaced planting of trees to maintain a persistent, healthy, and complete ground cover. In this article, we assess the economic implications to agriculture of the adoption of mitigation alternatives for erosion control in the Waikato District, New Zealand. The Waikato District presents a spatial pattern of erosion that affects profitability of dairy, and sheep and beef enterprises. We use the Universal Soil Loss Equation and the New Zealand Empirical Erosion Model to estimate erosion figures that are then fed into an economic‐focused, nonlinear, partial equilibrium mathematical programming model of New Zealand land use. Different scenarios are constructed for surface and mass‐movement soil erosion targets ranging from 0% to 50% below baseline levels. We find that achieving surface erosion targets is more expensive than mass‐movement targets, and results in different responses in regional‐level costs, land use, enterprise net revenue, and adoption of mitigation alternatives.     

2016年土地科学研究重点进展评述及2017年展望——土地管理领域分报告

研究目的：归纳分析2016年国内外土地管理领域的研究进展,展望研究趋势。研究方法：文献统计法。研究结果：2016年土地管理领域国外研究侧重于土地制度改革及其所产生的政治、经济、生态效应,土地法律与政策的作用效力及效应,土地权属与登记等方面;国内研究则更多关注农村土地制度改革、不动产登记成果整合应用、自然资源资产管理理论及成果应用、土地市场监管与土地财政影响、“三权分置”法律关系界定、集体土地所有权立法及集体成员资格界定、土地用途管制与耕地保护制度等相关问题。研究结论：2016年土地管理领域在不动产登记与自然资源资产管理、土地市场监管与调控以及土地用途管制方面的研究有所进展;2017年将重点关注土地管理制度改革、不动产统一登记制度的推进与完善、自然资源资产管理体制建设、土地及房地产市场调控,乃至农村土地市场的管理与调控、土地法律体系改革等方面。     

Food price increases and net food importing countries: lessons from the recent past

Recent increases in food and other commodity prices have highlighted concerns that many poor countries are net food importers and higher food prices would worsen their trade balances. In this article, we analyze the changes in food trade balances associated with the 32% increase in food prices from 2000/2001 to 2004/2005. We find a small deterioration in food trade balances of low‐income countries and an improvement in middle‐income countries. The deterioration is most severe for countries in conflict and small island states, so attention should be placed first on these countries and on a few very‐low‐income countries that are also vulnerable. Because low‐income countries as a group had much lower agricultural GDP growth rates than middle‐income countries, the answers to food vulnerability in low‐income countries should probably be addressed within the context of incentives for agricultural production.     

我国林业生物质能源发展相关政策概述

介绍了我国林业生物质能源发展的背景、现状和相关的政策,以及林业生物质能源相关的法律、能源林建设规划、相关的产业规划和财税扶持政策。提出今后我国林业生物质能源发展相关建议。