Econometric analysis of noncompliance with organic farming standards in Switzerland

Applying the economics of crime theory, we model the decision of an opportunistic and/or careless organic farmer and derive hypotheses to explain noncompliance. Where empirical data are available, hypotheses are tested. We use data for the years 2007 through 2009 of organic farms certified by Bio Suisse. Imposed sanctions are used as a proxy variable for noncompliance and farm characteristics as explanatory variables. Random effects logit models show that processing activities and livestock diversity significantly increase a farm's sanction probability. Past noncompliances also indicate a higher present sanction probability. Finally, we discuss some methodological issues and suggest a way to organize risk‐based inspections more effectively.     

水价与灌溉模式选择的博弈分析

运用博弈论方法建立了水价与井渠结合灌溉模式选择的博弈模型,对供水方与农户用水行为进行博弈分析,结果表明,实行渠水、井水统一水价,能有效激励农户采用井渠结合灌溉。按照博弈模型对宁夏引黄灌区采用地表水与地下水联合灌溉的节水效益进行研究。结果显示,采用井渠双灌,引黄灌区可减少渠首引水量1.53×10^8m^3／a,减少输水过程中的损失水量0.68×10^8m^3／a;如果政府将渠水和井水灌溉水价统一提高到0.04元／m^3,则井灌效益大于井灌投资,农户将积极采用井渠结合灌溉模式。     

破解水价改革难题的经济学分析

我国人多水少,水资源无偿和低价使用,利用效率和效益低下,加之水浪费、水污染严重,使得水资源供需矛盾成为我国经济社会发展的主要瓶颈。为解决水资源供需矛盾,必须加快水价改革,充分发挥市场配置水资源的决定性作用,通过实行用水计量收费和超额累进加价制度,在管理、供水、用水和排水等诸多环节建立激励约束机制,增强人们的节水动力,提高水资源利用效率和效益。     

农业水价综合改革的利益相关者分析

通过对我国农业水价改革的历程进行梳理,并基于利益相关者理论,将农业水价综合改革中所涉及的利益主体划分为农业水价影响者、农业水价承担者、农业水价执行者以及农田水利设施管理者四类,并分析四者的权力与利益,从而理清农业水价综合改革相关利益者之间的内在关系。提出农业水价影响者通过改善改革环境可以提高农业水价承担者缴费的配合度,双方的合作有助于实现双方利益的优化。农业水价执行者以及农田水利设施管理者的运营效率对农业水价影响者与农业水价承担者的利益具有重要的调节作用,但二者的运营效率均需要一定的资金支撑。最后就我国农业水价综合改革提出合理建议。     

我国地价结构的土地经济学分析

地价是土地市场的重要指标,地价结构能有效反应土地市场结构和状况。我国地价结构为商业地价住宅地价工业地价农业地价,这与传统的土地竞价曲线不一致。本文从产业布局、城市规划、政策导向等角度,运用土地经济学分析方法,重构了我国的土地竞价曲线模式,并对我国地价结构进行了合理解释。结合我国实际,在借鉴日本地价结构比例的基础上,本文提出了适合我国的地价结构比例的建议。     

A quantile autoregression analysis of price volatility in agricultural markets

This paper investigates the dynamics of agricultural price volatility based on a quantile autoregression (QAR) model. The QAR model provides a flexible representation of the distribution of price and its dynamics. The approach is applied to U.S. wheat and corn markets over the period of 1980–2017. This period is of significant interest as it covers important changes in agricultural policy and increased reliance on markets. The price analysis is conducted conditional on stocks held in the previous period. We show how increasing previous stocks shift the price distribution to the left and decreases the odds of facing price spikes (by shifting down the upper tail of the price distribution). Our analysis also examines the effects of changing public stocks on prices. For both wheat and corn, this reflects changing agricultural policy, contrasting the 1980s (when public stocks were relatively high) with the post-2005 period (when public stocks became zero). We document how higher public stock ratio during the previous period did not lower the odds of facing price spikes. Applied to the wheat and corn markets, we also uncover evidence of local dynamic instability in the upper tail of the price distribution, suggesting that price instability becomes more pronounced when previous stocks are low.     

Use of composite forest commodity price indices for cointegration analysis

Time series data on forest product prices used in research is frequently the product of temporal, spatial as well as product aggregation. This paper analyzes the implications of the use of composite commodity price indices in cointegration analysis and tests the validity of the assumptions underlying it. It tests for the presence of a common stochastic trend in disaggregated softwood lumber product price series in multiple US markets, a validity condition supported by the Generalized Composite Commodity Theorem (Lewbel, 1996. Aggregation without separability: a generalized composite commodity theorem. The American Economic Review 86(3), 524–543.). The presence of a common stochastic trend in softwood lumber product price series tested is consistently rejected by Johansen's (1988. Statistical analysis of cointegration vectors. Journal of Economic Dynamics and Control 12(2–3), 231–254.) multivariate cointegration analysis. Together with rejection of non-stationarity property for a significantly large number of price series tested, the results highlight the significance of the assumptions underlying the use of composite forest commodity price indices for cointegration analysis.     

地价和房价的经济学分析

土地的市场价值分析按照经济学的原理,土地的市场价值就是所有预期土地租金收入的未来值折现。也就是说一个每年都会创造出R收益的资产将连续创造n年的收益。如果市场的平均利率是r,那么评估这一资产现在的价值就需要把所有未来可能的收益按照平均利率折现到目前的时间点上:PV=nt=0∑(1 Rr)t其中,R是土地在某种用途下每年的租金,r是市场平均利润率,经过n年后土地的市场价值可以用PV的大小表示出来。如果这种预期的收益是无限期的,那么土地市场价值的算法可以简化为:PV=Ri现值是投资者愿意为某一土地支付的最大值,因为在这种情况下,投资…     

Evaluating alternative price expectation models for multiproduct supply analysis

Neoclassical economic theory provides an important conceptual framework for the analysis of agricultural production. Theory provides little guidance, however, in the actual specification of empirical models. This paper applies an integrated approach for choosing between price expectation mechanisms in a multiple-equation model when the alternatives are non-nested. Nine alternative specifications of market price and policy information are developed. Price forecasting accuracy, non-nested tests of hypotheses, and out-of-sample predictive accuracy are examined for agricultural production in Iowa. The results call into question the reliability of using forecasting accuracy as the sole guide to selecting a price expectation proxy.     

A comparative analysis of water price support versus drought compensation scheme

This paper examines the preferred governmental intervention towards crops growing methods in semi-arid regions. These regions are characterized by an average amount of rain which is sufficient to grow the crop but it is also very risky. The farmers' attitude towards risk motivates the government to encourage them to shift to more profitable and riskier crop rotations. The paper analyses two alternatives of which the government can work through: drought compensation scheme (DCS) and water price support (WPS). The semi-arid region in Israel is analyzed and policy conclusions are derived. In particular it is shown that for different sub-regions within the semi-arid region different mechanisms are preferred by the government and the farmers. Sometimes these mechanisms coincide and sometimes they do not. A welfare analyzes compares the different situations.     

山东省水资源价格波动效应的投入产出分析

针对水资源价格波动引起的国民经济各部门价格连锁反应问题,利用2012年山东省42部门以及139部门国民经济投入产出表,对水资源生产各部门的用水量进行分配,调整了投入产出,得到平衡的15部门价值型水资源投入产出表;应用投入产出价格波动模型分别计算50%、75%、100%3种水价上调方案对其他14部门以及对农业、工业、商业、公共服务四大产业价格的影响程度。研究结果表明,受影响最大的是公共服务部门,其次是农业、工业、商业,总体来说,水价提高对各类产品价格的影响程度均较低。     

An Econometric Model of the Canadian Agricultural Economy

This study presents an annual macro-type econometric model of the Canadian agricultural sector. The model is designed to depict and forecast some of the important activities of the agricultural economy. This agricultural model is linked with a well established existing econometric model of the Canadian economy—the TRACE model. Forecasting results using the agricultural model with and without the linkage with the TRACE modfhtre discussed. Government expenditure multipliers of the TRACE model with and without the linkage of the agricultural model are also examined and discussed.
Cette étude présente un modèle économétrique annuel de type macroéconomique du secteur agricole canadien. Le modèle est concupour décrire el pour prévoir quelques-unes des activités importantes de l'économie agricole. Ce modèle est liéà un modèle économétrique existant bien établi se rapportant à l'économie canadienne—soil le modile TRA CE. Nous discuterons de l'emploi du modèle agricole visant la prévision de résultats avec et sans la participation du modèle TRACE. Les mulliplicateurs des dépenses du gouvernement selon le modile TRACE avec el sans la liaison avec le modèle agricole seront également examinés et discutés.     

全球视角下粮食价格上涨的原因探析

2006年～2008年,我国主要粮食价格出现了大幅度上涨。忽视全球背景、忽视国内外粮食价格联动性增强这一事实,仅着眼于中国市场来探讨粮食价格波动问题,显然不够客观和全面。粮食价格的上涨,必须着眼于全球视角。以全球主要商品价格的走势、全球范围内主要粮食品种的供求矛盾为国际大背景,并结合国内的供求情况来探讨国内粮食价格上涨的主要原因。     

塔里木河流域未来农业水价调整的理论分析

依据塔里木河流域的水资源利用现状、水价资料及相关的调查,对塔里木河流域农业水价调整的现状和问题进行了分析.根据塔里木河流域农业水价调整的过程、特点、效应与价格形成机制,从流域水资源利用和管理的实际出发,提出了未来流域农业水价进一步调整的主要目标、指导思想和基本原则.同时基于水价调整的3重价格理论、水资源费种类的进一步细分,立足生态需水的环境水价计量分析,探讨了塔河流域未来农业水价调整的价格理论,阐明了未来流域农业水价进一步调整的研究内容.     

房价、地价与土地供应的前因后果

近年来,征地费用和拆迁费用越来越高,加大了土地取得成本,这种成本的升高,和土地出让方式是无关的。更重要的是,熟地价远远高于毛地价,由此导致的成本差异很大,对房价的影响迥然不同,不加区别地推论地价上涨对房价的影响是不科学的。就近期而言,土地供应量并没有大幅度减少。“三个暂停”以来,全国各地土地征占用数量有所减少,出现了“土地紧缩”,但是主导房地产开发的国有土地出让基本上没有受到影响,反而由于“8·31”大限,一些地区还呈现了大幅度增长的趋势。无论是协议出让还是招拍挂,都是土地市场中的资源配置方式,也可以说是一种形式。这种形式上的改革,充分体现了公开、公平、公正的原则。从对地价和房价影响的角度看,形式毕竟是形式,不会从本质上改变土地市场中最基本的供求矛盾,因而不能在根本上决定地价和房价的高低。     

农业水价改革的理论分析与路径选择

基于当前我国农业水价综合改革面临两难困境,从理论上分析农业灌溉供水的商品属性和公共物品特性,在此基础上,提出推进农业水价综合改革的"3+1"模式,即建立科学的水价形成机制、合理的水价管控机制、动态的水价调整机制和创新有利于推进农业水价改革的边界条件。     

Econometric Implications of Rectangular Hyperbolic Crop–Weed Competition

Estimation of the rectangular hyperbolic model of crop–weed competition by the method of maximum likelihood is investigated. Econometric implications of the rectangular hyperbolic form and normal stochastic specification are derived from the associated Fisher information matrix. Analysis explains some of the experience with the model in empirical work and clarifies the nature of statistical data that are advantageous to parameter estimation. Numerical examples are used to illustrate the relationship between the econometric problem and underlying information. Results provide agricultural economists with sound reasons for recommending specific changes in data collection choices although, in contrast to some existing perceptions, only some fairly minor changes in commonly used experimental design will be necessary to meet agricultural economists' research objectives. L'évaluation du modèle hyperbolique rectangulaire de la concurrence entre la récolte et les mauvaises herbes par la méthode de maximum de vraisemblance est étudiée. Des implications économétriques de la forme hyperbolique rectangulaire et du cahier des charges stochastique normal sont dérivées de la matrice associée de l'information de Fisher. L'analyse explique une partie de l'expérience avec le modèle dans le travail empirique et clarifie la nature des données statistiques qui sont avantageuses à l'évaluation de paramètre. Des exemples numériques sont employés pour illustrer le rapport entre le problème économétrique et l'information fondamentale. Les résultats fournissent aux économistes agronomes des raisons saines pour recommander les changements spécifiques des choix de collecte de données bien que, contrairement à quelques perceptions existantes, seulement quelques changements assez mineurs de conception expérimentale généralement utilisée seront nécessaires pour répondre aux objectifs des recherches des économistes agronomes.     

An Econometric Analysis of Yield Variability in Paddy Production

The objective of this paper is to extend the specification of conventional production functions to a stochastic production frontier in order to explain productivity differences among firms. This involves explicitly incorporating the random variability, which is beyond the farm operator's control, and the true farmer specific variability, which is under his control, into the model. Assuming a Cobb-Douglas production relationship, the model was estimated by the maximum likelihood method. Using the estimated results, the causes for the farmer specific variability were identified. Farmers' understanding of the technology and access to extension advice were the most important factors influencing yield variability.
L'objectifde cette communication est d'étendre la spécification desfonctions deproduction convenlionelle à la limite dune production stochaslique dans le but d'expliguer les différences de productivité entre firmes. Ceci implique l'incorporation au modele d'une part de la variabilité dûe au hasard el hors du contrôle de l'agriculteur, d'autre part de la variability specifique à I'agriculteur qu'il peut contrôler. Supposant un rapport de production Cobb-Douglas. le modèle a été eslime par la methode de probabilité maximum. Utilisant les resultals estimés. les motifs de la variabilité spécifique de I'agriculteur om été identifiés. La compréhension par l'agriculteur de la technologie el l'accès au conseil d'extension ont été les plus importants facteurs affectanl la variabilité des rendemenls.