Estimation and Application of a Production Function in Decision Rules for Swine Producers1

Production functions are estimated for swine based on experimental data designed for the purpose. The functions are estimated with gain as output and corn and protein supplement as inputs. The gain functions are first estimated for five trials with different starting weights. With use of dummy variables, the data are then pooled for estimation of a single overall production function. Among several algebraic forms used in estimation, a quadratic equation was selected for application. Derivation and estimation of gain isoquants are illustrated and comparison is suggested with a previous study where the isoquants are estimated directly by means of an instrumental variable approach to circumvent problems of autocorrelation. The data then are used in a production decision model which considers fluctuating prices.
Des fonctions de production porcine sont estimées à partir de données expéri-mentales developées à cette fin. La fonction de production est représentée par le gain de poids avec le maïs et les supplements de proteine jouant le rôle de variables. Les gains de poids sont dabord estimés sur cinq essais à partir de divers poids ini-tiaux. Les données sont ensuite combinées à l'aide de variables annexes afin destimer une fonction de production générale. Parmi les diverses formes algebriques employées lors de l'estimation une équation quadratique fût sélectionée comme application. L'estimation et l'obtention des isoquantes gain de poids sont présentés. Une comparaison est faite avec une étude antérieure où les isoquantes sont directement estimées à partir de variables instrumentales ce qui évite les problémes d'autocorre-lation. Les donnees servent ensuite dans un model de décision de production qui comprend des fluctuations de prix.     

GROWTH AND SIZE ECONOMIES OVER SPACE AND TIME: WHEAT-SHEEP FARMS IN NEW SOUTH WALES

Time series and cross-sectional data for 18 years on 26 N.S.W. wheat-sheep properties are combined to test whether farms that grew in size over time reaped the postulated size economies derived from the cross-sectional statistical cost functions. Realised economies of farms that remained in the industry and changed in size during the 18-year period were found to be significantly greater than measured potential economies from 'static' cost functions would have suggested. The 'dynamic economies of growth' differed significantly amongst farms indicating there was no single economy of size curve along which farms moved.     

The Potential for Nitrogen Abatement Trading in Agriculture: A Hypothetical Market Experiment

The effectiveness of nitrogen abatement trading as a policy measure relies on both heterogeneity in costs and environmental effectiveness across landscapes. Cost‐efficient implementation may therefore critically depend on spatial distributions of farm and farmer characteristics in water catchments. We use a spatially specific hypothetical market experiment to analyse the likelihood of farmers’ enrolment into nitrogen abatement trading contracts, and derive demand and supply functions for farmers’ nitrogen abatement. We find that farm characteristics influence both the decision whether to supply or purchase nitrogen abatement, as well as the amounts being traded. The derived demand and supply functions for farmers’ N abatement, using hypothetical market experiment data, can be used to reveal the variability in costs of abatement within a market. This provides valuable information to test potential trading schemes ex ante, to evaluate potential economic gains from policy implementation.     

MODELLING FERTILISER DEMAND IN THE REPUBLIC OF IRELAND: A COST FUNCTION APPROACH

A translog cost function was used to obtain estimates of the own- and cross-price demand elasticities for nitrogen, phosphorus and potassium. The results indicated a mean value for the own-elasticities of —1.0, —0.6, —0.5 for N, P and K respectively. A test of the hypothesis of nutrient substitution was attempted. The test indicated that P and K were substitutable for N but not for each other. This result was corroborated by a zero elasticity of substitution estimate between phosphorous and potassium. A corollary of the results was the rejection on empirical grounds of the Cobb-Douglas specification for the input demand functions. The latter function has traditionally been used in analyses of this nature.     

农业科技园区的经济发展带动效应——来自河北省县域的实证评估

目的 农业科技园区作为农业现代化的示范基地,发挥着拓展农业功能、促进农业经济增长的作用。文章将评估农业科技园区的经济发展带动效应。方法 将农业科技园区视为一项“准自然实验”,以2007—2020年河北省167个区县的面板数据为研究样本,运用多期双重差分模型,评估了河北省省级以上农业科技园区对农业经济的影响。结果 （1）农业科技园区总体上显著提高了农业产值,从而有效带动当地农业经济发展水平,这一结论在经过安慰剂检验、稳健性检验后依然稳健。（2）机制分析表明,农业科技园区能够通过科技创新促进农业经济的发展;异质性分析结果显示,农业科技园区对农业经济的影响在不同等级、不同地理空间、不同行政层级中存在差异。结论 河北省应继续加大农业科技园区的建设力度,持续提升科技园区创新水平以助力实现河北省农业高质量发展。     

Stochastic Production and Heterogeneous Risk Preferences: Commercial Fishers' Gear Choices

We present a model of fishers' gear choice, which allows for heterogeneity both in production technology and risk preferences and apply it on a panel of Swedish trawlers. Stochastic revenue functions are estimated and used to predict the mean and standard deviation of revenue for each trip. In a random-parameters logit model, we test if these predicted values explain gear choice. A majority of fishers respond positively to increased mean and negatively to increased variability of expected landing values, indicating risk aversion, but also show a strong tendency to choose the same gear used on the previous trip.     

Dynamic adjustment in the US beef market with imports

This paper hypothesizes that while there are important qualitative differences in domestic beef and imported beef, beef and cattle imports also represent attempts by the US beef processing and wholesale sector to adjust to short-run changes in supply and demand. Dynamic production theory is applied to the problem to test for this adjustment process, and presents a production theory approach to meat trade that has previously been included in demand functions. The results of this analysis suggest that the method used provides a reasonable and appropriate representation of the import behavior of the US processing and wholesale beef sector.     

农村集体建设用地流转的驱动机制分析

从社会经济、土地制度等因素出发,结合经济计量模型进行实证检验,探讨了农村集体建设用地流转的驱动机制。结果表明:社会经济因素、土地制度因素显著影响了农村集体建设用地流转。具体来看,非农产业发展水平、农地管制水平以及土地市场发育程度,与农村集体建设用地流转规模显著正相关,是农村集体建设用地流转的主要驱动力;城镇化发展、固定资产投资也在一定程度上影响了农村集体建设用地流转进程;并且集体建设用地流转存在明显的地域差异。因此,加强流转的规范管理应该从多方面着手,通过完善相关法律法规,科学编制土地利用规划,加强土地市场建设,从而保障农村集体建设用地流转的顺利进行。     

Estimating Price Elasticities of Food Trade Functions: How Relevant is the CES‐based Gravity Approach?

The main objective of this article is to examine econometric estimates of price elasticities of food trade functions. We investigate the relevance of the prominent gravity approach. This approach is based on the assumptions of symmetric, monotone, homothetic, Constant Elasticity of Substitution (CES) preferences. We test all these assumptions using intra‐European trade in cheese. In general, the assumptions made on preferences by the gravity approach are not supported by our dataset. The bias induced in the estimated price elasticities is ambiguous.     

双杏低糖牛轧糖的制作工艺研究

本文根据前期牛轧糖的市场调研、消费者诉求及相关文献对传统牛轧糖的配方进行考察并优化制作工艺.以苦杏仁和甜杏仁为主要原料,以海藻糖代替部分白砂糖,研制一款兼具营养保健功能的低糖健康牛轧糖.为优化双杏低糖牛轧糖的制作工艺,通过单因素试验和正交试验,以感官评价结合质构检测值为指标确定最优工艺配方(以总糖浆质量计).结果表明,...     

Is Risk Aversion Really Correlated with Wealth? How Estimated Probabilities Introduce Spurious Correlation

Economists frequently focus on correlations between wealth and risk preferences but rarely observe the probabilities needed to test this relationship empirically. These unobserved probabilities are typically estimated via profit or production functions conditioned on wealth correlates, which may leave statistical fingerprints on subsequently-estimated risk aversion coefficients and confound correlations between wealth and risk preferences. Using data from an experiment with observable probabilities, we compare risk aversion coefficients based on true probabilities with those based on probabilities estimated using standard approaches and show how estimated probabilities can change risk aversion coefficients substantially and introduce spurious correlation between risk aversion and wealth.     

城乡统筹视野下农村干部培训体系构建——基于高校培训模式的研究

城乡统筹背景下新农村建设对农村干部培职能提出了新要求，高校迎合时代需求参与农村干部培训，既是干部培训发展的必然趋势，也是高校服务农村发展的重要途径。本文在总结以往培训经验的基础上，结合当下遇到的问题，提出高校应充分利用自身优势，科学论证培训项目；不断创新培训模式；逐步建立和完善培训管理长效机制；在课程设置上应适应农村产业结构调整。     

董事会异质性、企业绩效与碳信息披露——基于造纸业上市公司的实证研究

借助董事会异质性与企业绩效视角考察碳信息披露的影响因素,结合威胁刚性理论检验企业绩效是否产生调节效应。统计2012-2017年造纸行业样本数据,研究结果显示:董事会性别、任期和教育异质性显著作用于碳信息披露,且前两者具有抑制功能,后者具有促进功能;企业绩效对碳信息披露水平产生负向影响,而对董事会异质性作用不产生正向调节效应。研究结论可以指引企业调整董事会架构、改善碳信息披露现状,亦可以拓宽企业绩效作用解析思路、丰富相关经验证据。     

CAP payments and spatial diversity in cereal crops: An analysis of Italian farms

Agricultural biodiversity conservation has been recognized as a fundamental resource for the maintenance of ecological and economic functions. In this paper, we test the hypothesis that the Common Agricultural Policy (CAP) has an impact on crop diversity decisions of farm managers. In so doing, we allow the diversity decision to depend on a rich set of economic and agro-ecological variables, such as prices of the most common cereal varieties, and agro-ecological and socio-economic characteristics at farm and regional level. Using a panel dataset over the period 2004–2010, we compare the results obtained from pooled-OLS and dynamic panel GMM estimators. The empirical analysis shows the existence of a positive relationship between CAP payments and diversity. In addition, decoupling subsidies from production seems to have a positive effect on biodiversity.     

Differences in agricultural returns: an empirical test of efficiency in factor input allocation using Vietnamese data

We study whether rural households in Vietnam allocate their factor inputs efficiently. Factor returns and technical rates of substitution (TRS) between production activities are compared. We estimate two translog production functions and conduct three tests: First we test the equality of bootstrapped returns. Second, we use a bootstrapped t -test comparing the equality of TRS. Finally, we derive a set of nonlinear restrictions on our estimated parameters, which, if held, would imply that we cannot reject efficiency. The article concentrates on the allocation of factors between the cultivation of the two most important agricultural crops—sugar cane and rice. We cannot reject the possibility that households are efficient in their input allocation. These results are consistent and stable over different estimation techniques and support the assumption of profit maximization.     

土地功能研究进展与方向的思考

研究目的:对国内外土地功能研究主要成果进行总结与评述,提出新的研究方向及思路,供深入开展土地功能研究参考。研究方法:文献综述法和逻辑分析法。研究结果:土地功能概念与内涵尚待形成共识,土地功能分类正在积极探索,土地功能评价有了初步分析框架并在尝试应用。研究结论:土地功能研究已有良好基础,发展趋势和前景看好,应进一步强化基础研究,深化实践应用,不断创新,支持土地资源可持续利用,支撑土地科学学科建设与发展。建议研究方向包括:完善土地功能概念与内涵知识体系,创建土地功能研究框架;完善土地功能系统分类;深化土地功能形成要素的特征尺度研究;加强土地功能研究成果的应用。     

On the use of flexible mixing distributions in WTP space: an induced value choice experiment

In this study, we use data from an induced value choice experiment to compare estimates from mixed logit models in willingness to pay (WTP) space using different parameter distributional assumptions. Specifically, we test differences in WTP estimates when using flexible parameter mixing distributions (i.e. Legendre polynomials, step functions and splines) and conventional parameter distributions (normal and lognormal). Similar WTP estimates are obtained. However, we observe that WTP estimates are statistically different from the induced value when conventional distributions are assumed, but they are not when more flexible distributions are assumed. This suggests that flexible distributions can provide more reliable WTP estimates.     

Price Relationships in Processors' Input Market Areas: Testing Theories for Corn Prices Near Ethanol Plants

This study examines corn pricing in the vicinity of processing plants. We develop and test several price-distance models for cargo, insurance and freight (CIF) plant pricing in the presence of varying degrees of exporter competition, and for discriminatory free-on-board (FOB) pricing at the farm. The price-distance functions describing spatial prices near processing plants all depend on local transport costs. But the pricing system (CIF or FOB) and the extent of local competition define the level and spatial rate of change in prices.Estimations of an empirical price-location function for Iowa during the spring of 2003 suggest that prices near the plants of four conventional businesses conform to the CIF pricing model. But prices near producer-owned firms or farmer cooperatives failed to show any statistically significant effect on nearby prices. One plant had a price-distance function that resembled FOB pricing.     

A FAMILY OF AGRONOMIC PRODUCTION FUNCTIONS WITH ECONOMIES OF SCOPE

This paper derives a family of multiple-output multiple-input production functions from the underlying technologies. These technologies are represented by average yield functions for each of the commodities (crops) produced from a common pool of resources. The production functions are implicitly separable. Examples include the CRETH, translog, generalised power and generalised McFadden functions. Moreover, given a function which is a member of this family, the individual commodity yield and production functions can be recovered. Such implicitly separable multiple-output production functions may exhibit economies or diseconomies of scope which reflect the interactions between outputs sharing a common pool of resources.     

乡村振兴背景下宅基地多功能权衡与协同研究——以德清县为例

目的 识别与量化宅基地多功能，分析宅基地功能间权衡与协同关系，为乡村振兴背景下宅基地功能优化提供科学依据。方法 文章基于要素和结构识别宅基地多功能，构建评价指标体系测算宅基地功能值，综合运用Spearman相关性分析和生产可能性边界度量和分析宅基地功能间权衡与协同关系。结果 （1）德清县的宅基地以社会、生态功能为主，经济、文化功能为辅，不同类型村庄的宅基地多功能表现有差异：相较于集聚提升类、城郊融合类和搬迁撤并类村庄，特色保护类村庄的各项功能具有明显优势。（2）德清县的宅基地生态、社会功能间呈中度协同关系，经济、社会功能间呈中度权衡关系，经济、生态功能间呈弱权衡关系，宅基地功能权衡强度在不同类型村庄显现差异：搬迁撤并类的经济、社会功能间权衡强度最大，特色保护类的经济、生态功能间权衡强度最小。结论 宅基地功能间存在显著的权衡与协同关系，未来应结合不同类型村庄的发展目标制定差异化的功能优化策略。