建立合理勘查开发模拟与矿业循环经济的应用

我国矿产资源供需矛盾日趋尖锐,矿产资源的可持续利用日益成为公众关注的重点。我国正处于工业化中期阶段,矿产资源供需形势严峻,环境压力大,固体矿产合理勘查开发应采取双控论和合理域概念模型,建立矿业风险投资与决策支持系统,在原有循环经济"3R"原则基础上结合矿产资源的特点,在矿产资源领域发展"5R"循环经济,即遵循再发现、减量化、再利用、再循环、复垦五项原则以促进矿业的可持续发展。     

外卖餐盒逆向物流回收模式研究

随着"互联网+"外卖平台的盛行,外卖餐盒数量大、回收难问题日益凸显。本文分析了"互联网+"逆向物流的趋势,基于外卖餐盒回收现状及存在的问题,提出了几种不同外卖餐盒的回收模式。     

A revised Tobit procedure for mitigating bias in the presence of non-zero censoring with an application to milk-market participation in the Ethiopian highlands

Fixed transactions costs that prohibit exchange engender bias in supply analysis due to censoring of the sample observations. The associated bias in conventional regression procedures applied to censored data and the construction of robust methods for mitigating bias have been preoccupations of applied economists since Tobin [Econometrica 26 (1958) 24]. This literature assumes that the true point of censoring in the data is zero and, when this is not the case, imparts a bias to parameter estimates of the censored regression model. We conjecture that this bias can be significant; affirm this from experiments; and suggest techniques for mitigating this bias using Bayesian procedures. The bias-mitigating procedures are based on modifications of the key step that facilitates Bayesian estimation of the censored regression model; are easy to implement; work well in both small and large samples; and lead to significantly improved inference in the censored regression model. These findings are important in light of the widespread use of the zero-censored Tobit regression and we investigate their consequences using data on milk-market participation in the Ethiopian highlands.     

农用地膜污染合作治理模式及其绩效损失研究

[目的]农用地膜污染防治是推动农业农村污染合作治理、实现农村人居环境持续改善的重要内容,因此系统研究不同主体在农用地膜回收利用工作中行为模式的差异及影响因素,可为全国农用地膜污染治理提供可借鉴的方法和经验。[方法]文章基于农用地膜生命周期污染防治的逻辑链条分析,系统研究了废旧地膜回收过程中的价值生成和绩效损失途径,提出地膜污染防治典型合作模式与治理路径。[结果]废旧地膜回收机制建立初期,政府通过产业政策导向培育环保意识和市场,通过补贴实现企业的规模扩大和持续发展,但会降低企业核心竞争力,造成政府在生产环节的绩效损失。[结论]在典型农用地膜污染治理模式中,政府主导型、混合型模式适合废旧地膜回收机制建立初期,有利于从宏观层面调动市场资源,建立起“生产—回收”的市场内循环机制;在市场内循环机制建立成熟后,一般由政府主导型转为混合型,并在混合型后期逐步过渡为生产者主导型,使得废旧地膜回收利用成为一个非政府主导行为。     

Recycled Effluent: Should the Polluter Pay?

A coastal city can either dispose of recycled effluent by dumping it in the sea, or transfer it to farmers in its hinterland for irrigation. Who should bear the cost of recycling? Three alternatives are employed: a central planner who maximizes the combined utility of city and farmers; regulation by prices, for which purpose we develop the city's supply function; and a bargaining framework for the allocation of costs. The main conclusions are that "the polluter pays" rule cannot be justified in principle and that bargaining may result in inefficiency. We demonstrate with an example from Israel that essentially conforms to the theoretical structure.     

我国海岛型循环经济发展之路探析——以海南省为例

循环经济是国际社会推进可持续发展战略的一种优选模式,强调最有效地利用资源、保护环境,以最小成本获取最大的经济、社会和环境效益。这种经济发展模式对像海南这样一个既需要经济高速增长而资源又相对稀缺的海岛型区域经济的发展具有重要指导意义。文章通过对循环经济模式和海南岛屿自身发展条件的分析,提出遵循循环经济原则,走"绿色发展"之路是海南的必然选择。     

基于二元Logistic与ISM模型的农户地膜回收的影响因素分析——以新疆为例

目的 地膜覆盖技术对于我国粮食安全保障意义重大，但目前残膜污染的回收治理效果仍不理想。农户是地膜回收过程中的关键主体，分析农户地膜回收行为的影响因素对于推动残膜回收，促进农膜残留污染治理与地膜覆盖技术绿色可持续应用具有重要意义。方法 文章基于新疆333份农户的调研数据，运用二元Logistic与解释结构模型（ISM）相结合的分析方法，分析了农户地膜回收行为的影响因素，以及影响因素之间的关联性层次性。结果 （1）二元Logistic模型结果显示：地膜使用年限、耕地面积、耕地细碎化程度对农户地膜回收行为具有显著负向作用。地膜厚度、再次利用价值认知、残膜危害了解途径多寡、环境监督、回收企业、回收补贴对农户地膜回收行为具有显著正向作用。（2）ISM模型结果显示：补贴是深层根源因素，是否有补贴影响当地回收企业补贴的建立；地膜使用年限、地膜厚度、回收企业、环境监督为中层间接因素；耕地面积、耕地细碎化程度、回收后再次利用价值认知、残膜危害了解途径多寡为表层直接根源因素。结论 农户地膜回收影响因素可归纳为“两驱动，三路径”。为改善农户地膜回收行为，促进地膜覆盖技术绿色发展，应保障地膜质量，推动农村土地流转，发展机械化回收技术，同时完善回收体系，拓宽农户的了解渠道。     

草原补奖政策:“高满意度与低执行度”悖论的形成机理研究

本文以草原补奖政策"高满意度与低执行度"悖论为议题,基于内蒙古锡林郭勒盟209户调研数据,实证检验牧户政策目标认知对超载规模的作用,并依次讨论不同认知群体的满意度对履规行为的影响,推导出"既高又低"悖论的形成机理。研究认为,目标认知偏差是造成此悖论的主要因素,政策目标认知对超载程度影响显著,生态恢复认知牧户比提高收入认知牧户的超载程度更低,前者政策满意程度正向影响其履规行为,但后者此机制不明显。对草场退化原因的理解差异、对超载放牧的弱监管以及对补奖资金发放执行不力是造成目标认知偏差的主因,对此,本文建议从加强宣传与政策解读、放大监管作用和地位、实施差异化补奖模式等方面入手,促进政策执行度的提升。     

石家庄区域农业循环经济发展的灰色关联分析

[目的]通过构建一套适用于区域农业循环经济发展的评价指标体系,利用灰色关联分析对区域农业循环经济的发展水平进行综合评价。[方法]采用AHP方法构建区域农业循环经济发展评价指标体系,进一步采用灰色关联分析法构建区域农业循环经济发展评价模型,对石家庄2000~2015年的农业循环经济发展水平进行了评价。[结果]从发展评价结果来看可以划分为3个阶段,即缓慢下滑阶段(2000~2004年)、快速下滑阶段(2005~2008年)和快速上升阶段(2009~2015年)。从各类指标灰色关联度数值变化情况来看可将其划分为2种类型:(1)包括农业经济发展和农业产出等2类指标,其关联度数值都呈快速增长态势;(2)包括资源减量投入、资源循环利用以及生态环境等3类指标,其历年灰色关联度数值变化均具有先减小再增大的特点。[结论]石家庄农业循环经济发展的整体水平不高,并呈现"U"型特征。     

基于主成分分析的山西省农业循环经济发展水平评价研究

[目的]农业循环经济是我国农业可持续发展的必由之路,对农业循环经济发展水平的评价是该领域研究的关键。[方法]构建包含社会、经济和生态效益的农业循环经济评价指标体系的基础上,运用主成分分析法结合线性回归方程对山西省2001~2016年农业循环经济发展水平进行评价和分析。[结果](1)山西省农业循环经济发展水平的评价因素可归纳为生产资料集约水平、资源修复水平和土地集约水平3方面。(2)山西省农业循环经济在2001~2016年总体呈现上升趋势;并分为两个发展阶段,2001~2009年农业循环经济发展低水平阶段和2010~2016年农业循环经济发展上升阶段。(3)2010年之后山西省转变传统农业发展方式、实现农业循环经济取得一定成效,生产资料集约水平是促使山西省农业循环经济发展提升的主要动力。[结论]山西省转变传统农业发展方式,提升农业循环经济发展水平,使农业走可持续发展道路注重生产资料的集约是关键,可以从控制化肥、农药、农膜投入量,提升其有效利用系数等方面入手;其次要提升资源修复水平,利用秸秆还田的形式增加废弃物利用率,增加水土流失治理面积;并提高土地利用率。     

黑龙江省林业循环经济发展水平评价研究

首先根据循环经济的"3R"原则和黑龙江省林业循环经济发展的实际情况,建立了林业循环经济发展水平评价指标体系;然后依据黑龙江省2001年到2011年的指标数据,运用主成分分析方法,综合分析出黑龙江省林业循环经济总体发展趋势,并从资源消耗、资源循环利用、社会和经济发展、生态环境4个方面分阶段评述了黑龙江省林业循环经济的发展水平,浅析了各阶段取得成效和存在问题的原因。     

COMPARATIVE EFFICIENCY OF RICE FARMS IN CENTRAL LUZON,THE PHILIPPINES

The purpose of this paper is to estimate a bias-free agricultural production function with a view to examining efficiency differences among small rice farmers. Simultaneous equation bias is avoided if we assume that farmers maximise expected profits; specification bias, which commonly occurs when a management input is omitted from such functions, is circumvented by introducing farm-specific dummy variables into a combined cross-sectional and time-series data set. Applying this model to data for 32 Philippine rice farms between 1970 and 1979, rather small production-elasticities are obtained for the conventional inputs and an efficiency ranking of the farms is presented. Second stage analysis shows that differences in soil type, land tenure, education and access to credit are important factors explaining these efficiency differences.     

循环经济与土地资源的可持续利用

我国土地资源的严峻形势迫切要求土地的可持续利用。循环经济作为一种新的经济发展模式,运用循环经济“减量化、再使用、再循环”的理念指导土地利用总体规划修编、生态园区建设、新经济核算体系建立、生态退耕和土地整理复垦,可以节约和集约用地,提高土地质量,从而保证土地资源的可持续利用。     

Quantifying the Economic Return to Participatory Extension Programmes in Ireland: an Endogenous Switching Regression Analysis

This article examines the effectiveness of a government funded extension programme. Farm‐level data are used to assess the economic impact of dairy discussion groups, a common participatory extension method. The evaluation focuses on whether discussion group participants have improved farm profits, which is estimated with an endogenous switching regression model. This method controls for self‐selection bias due to unobserved characteristics, such as the farmer’s ability, that may affect both participation and farm profitability. After controlling for this potential bias, we find that the economic returns to discussion group membership are positive, thus supporting government targets to enrol more farmers in discussion groups.     

基于灰色关联的西北地区农业循环经济发展评价

[目的]发展农业循环经济有利于缓解西北地区农业资源与生态环境的压力,促进传统农业转型,刺激农业经济的增长,实现农业的可持续发展。[方法]文章通过构建西北地区农业循环经济指标体系,运用灰色关联法计算关联度并分析比较各影响因素间的相对变化程度用来分析西北地区农业循环经济的发展水平。[结果]关联系数结果表明影响陕西地区农业循环经济的因素主要是农民人均纯收入、农药施用量、农业柴油施用量、有效灌溉面积及禽畜粪便利用率;影响甘肃省的农业循环经济发展的因素主要是农民人均纯收入、复种指数、秸秆利用率及禽畜粪便利用率;影响青海地区农业循环经济的因素主要是人均粮食产量、节水灌溉面积以及秸秆利用率;影响宁夏地区农业循环经济的因素主要是农林牧渔业增加值、节水灌溉面积、有效灌溉面积以及秸秆利用率;影响新疆地区农业循环经济的因素主要是农药施用量、复种指数、有效灌溉面积及禽畜粪便利用率。关联度大小结果表明西北地区农业循环经济的发展水平从大到小依次为宁夏(0. 743)、甘肃(0. 716)、青海(0. 674)、新疆(0. 619)、陕西(0. 585),针对青海、新疆和陕西地区应采取相应措施,促进农业循环经济的发展,进而提高西北地区农业循环经济的整体水平。[结论]在西北地区发展农业循环经济,应重点加强资源减量化和再利用方面的建设,以及平衡区域间的协调合作发展,推动农业循环经济的健康持续发展。     

Bias from Farmer Self‐Selection in Genetically Modified Crop Productivity Estimates: Evidence from Indian Data

In the continuing debate over the impact of genetically modified (GM) crops on farmers of developing countries, it is important to accurately measure magnitudes such as farm‐level yield gains from GM crop adoption. Yet most farm‐level studies in the literature do not control for farmer self‐selection, a potentially important source of bias in such estimates. We use farm‐level panel data from Indian cotton farmers to investigate the yield effect of GM insect‐resistant cotton. We explicitly take into account the fact that the choice of crop variety is an endogenous variable which might lead to bias from self‐selection. A production function is estimated using a fixed‐effects model to control for selection bias. Our results show that efficient farmers adopt Bacillus thuringiensis (Bt) cotton at a higher rate than their less efficient peers. This suggests that cross‐sectional estimates of the yield effect of Bt cotton, which do not control for self‐selection effects, are likely to be biased upwards. However, after controlling for selection bias, we still find that there is a significant positive yield effect from adoption of Bt cotton that more than offsets the additional cost of Bt seed.     

Effects of Cheap Talk on Consumer Willingness-to-Pay for Golden Rice

A large body of literature suggests willingness-to-pay is overstated in hypothetical valuation questions as compared to when actual payment is required. Recently, "cheap talk" has been proposed to eliminate the potential bias in hypothetical valuation questions. Cheap talk refers to process of explaining hypothetical bias to individuals prior to asking a valuation question. This study explores the effect of cheap talk in a mass mail survey using a conventional value elicitation technique. Results indicate that cheap talk was effective at reducing willingness-to-pay for most survey participants; however, consistent with previous research, cheap talk did not reduce willingness-to-pay for knowledgeable consumers.     

从大农业视角剖析中国水产业与循环经济

作者试图从我国粮食安全保障角度出发,在分析了我国水产业的现状与问题的基础上,为"紧缺资源替代"战略的一个重要组成部分的必要性与可行性.同时文中讨论了"循环经济"基本理念,并提出了我国水产业实施"循环经济"的"社会大循环"、"企业间循环"、"企业内循环"三个可供选择的基本模式,体现了"资源节约"精神与产业可持续发展的原则.     

Using Ex Ante Approaches to Obtain Credible Signals for Value in Contingent Markets: Evidence from the Field

While contingent valuation remains the only option available for measurement of total economic value of nonmarketed goods, the method has been criticized due to its hypothetical nature. We analyze field experimental data to evaluate two ex ante approaches to attenuating hypothetical bias, directly comparing value statements across four distinct referenda: hypothetical, "cheap talk,""consequential," and real. Our empirical evidence suggests two major findings: hypothetical responses are significantly different from real responses; and responses in the consequential and cheap talk treatments are statistically indistinguishable from real responses. We review the potential for each method to produce reliable results in the field.     

农业资源循环利用与区域特色产业融合研究——以河南周口地区为例

[目的]文章以河南周口地区为例,对当地农业资源循环利用和区域特色产业融合进行实地调研和分析,探讨促进二者协同发展的新举措,以期为当地和其他地区的农业发展提供借鉴。[方法]该文采用实地调查法和统计分析法,了解周口地区农业资源现状以及农业资源循环利用与区域特色产业融合的情况,分析农业资源循环利用的必要性以及与区域特色产业融合的重要性,并提出相关改进措施。[结果]周口地区粮食资源丰富,产量很大,农业的发展主要依靠农用化学品、农业自然资源进行农业生产,单纯追求粮食产量的线性发展,发展模式是"资源投入-生产活动-产品和废弃物",农业资源的循环利用率不高,忽视了农业生态环境的保护。周口地区的农业生产经营原本以个体户为主,随着规模化发展,形成种养大户、龙头企业、家庭农场等,围绕农业生产的特定环节和生产流程,推行农业资源的循环利用。但是在这一过程中,由于土地的过度开垦、大量农药化肥的使用、基础设施不完善等问题,使周口地区的农业生态环境不断恶化,盲目的循环投入而不是资源的循环利用,使农业的可持续发展受到限制,影响了区域特色产业的融合。[结论]河南周口地区农业资源丰富,而农业生产发展模式较为单一,农业资源利用率不高,在农业生产过程中忽视了对农业生态环境的保护。该地区应结合地方产业优势,使农业废弃物资源与养殖业发展形成循环产业模式,转变发展观念,形成农业资源循环利用与区域特色产业的良性互动,促进地区产业的发展。