LABOUR INPUT DECISIONS OF SUBSISTENCE FARM HOUSEHOLDS IN SOUTHERN MALAWI

The objective of the paper is the presentation of a farm-household model which allows an analysis of labour input decisions of rural households in an environment with risky agricultural technologies and off-farm employment opportunities. Labour input decisions are condensed into a stochastic linear programming framework, and applied to a typical rural household in Southern Malawi. Weak adoption of yield-increasing technologies is explained by different opportunity costs of time of family members and by the risky nature of income generated using traditional or yield-increasing agricultural technologies. The view that land-saving innovations will increase agricultural production is revised. Special extension programmes for family members with low off-farm employment opportunities are proposed to increase the adoption of those technologies. These programmes have the purpose of reducing anticipated subjective income deviations for yield-increasing innovations.     

Pollution abatement and productivity performance of regional Canadian pulp and paper industries

The performance of pulp and paper industries in four Canadian regions is compared based on the estimation of an input distance function, with and without pollutant outputs. Distance functions are techniques for the representation and estimation of multiple-output and multiple-input production technologies. They are quantity-based techniques. Non-marketed outputs such as pollutants can be easily incorporated into productivity analysis with the help of distance functions. This environmentally sensitive approach provides higher productivity growth estimates for all regions, indicating the need for adjusting conventional measures that ignore the non-marketed benefits of pollution abatement activities. The results also consistently indicate the presence of substantial differences in the regional levels of technical efficiency. Regional industries have not enjoyed similar rates of technological progress due to differences in their underlying structures. Productivity growth estimates for most regional industries remain weak or negative even after the recognition of pollution abatement efforts. Estimates of regional level costs of abatement for biological oxygen demand (BOD) and suspended solids (TSS) are provided.     

Free in the mountains or home in the vineyard: Institutional changes in agriculture and negotiating between contract farm labour and valuable fungi collection in Tibet

This paper evaluates how Tibetan farming communities choose between two methods of livelihood production: working as labourers on vineyard land they have leased to a French winery or collecting valuable fungi. I argue new transnational land and labour management, as part of institutional rearrangements in land tenure, are leading to significant changes with mixed benefits for rural farming communities. These communities respond by seasonally seeking freedom from capitalist labour and returning to communal forms of income production based around community land tenure and common‐pool resources. Although villagers have become contracted labour, they choose to escape this new agricultural work in the mountains, collecting fungi together as a community. The common‐pool land on which fungi are collected is also managed for access in a specific way by and for the community. Contrary to agricultural labour for the winery, fungi collection creates a chance for people to interact once again more as a cohesive community as they once did in their fields by collecting a commodity from land controlled by the community. The disembedding of one section of the economy has thus in a way reinforced the embeddedness of social relations in another as a coping mechanism for the former.     

农业资源利用与粮食综合生产能力的灰色关联分析——以河北省为例

文章首先对河北省农业资源利用现状进行了分析(主要包括自然资源、经济资源和社会资源),其次对河北省粮食综合生产能力进行了现状分析,在此基础上确定了影响河北省粮食综合生产能力的3类因素10个指标,同时选取2004~2014年上述10个指标的统计数据,运用灰色关联分析法进行分析得出的结论是:农业机械总动力、农用塑料薄膜使用量、农药使用量与粮食总产量高度相关,对提升粮食综合生产能力影响大;其它影响因素按照关联度由大到小排列为:农用化肥施用折纯量、农业从业人员、农村用电量、人均耕地面积、粮食播种面积、农林牧渔业总产值、水土流失治理面积它们都与粮食产量中度相关,对提升粮食综合生产能力影响较大。最后提出充分利用农业经济资源是促进粮食稳产增产的首要途径、充分利用社会资源是促进粮食稳产高产的重要途径、保护耕地资源是基础等对策。     

水足迹视角下京津冀县域粮食作物水土资源匹配格局

[目的]农业水土资源是粮食生产的决定因素,探明京津冀粮食生产中水土资源匹配格局特征对区域经济发展有深远的影响。[方法]文章从水足迹的视角出发,分析了1980—2018年京津冀县域5种主要粮食作物（小麦、玉米、稻谷、大豆、薯类）的产量、播种面积、水足迹、耕地面积的时空变化,运用水土匹配系数法及ArcGIS深入研究了1983年、1998年、2003年和2016年水土资源匹配格局,并进一步剖析区域农业水土匹配对农业生产的影响。[结果]（1）当前京津冀水土匹配系数区间为[0.02,1.25],超出区间范围[0.281, 0.431];粮食生产格局与水土匹配系数空间格局均为“冀中南高、北部低”。（2）研究时段内,京津冀粮食总产量提高1.14倍,播种总面积降低19.28%,粮食单产量显著提高;灌溉提高粮食单产量,水土匹配系数与粮食单产量呈正相关。（3） 1980—2019年京津冀5种作物蓝水足迹均值（136.64亿m3）是绿水足迹均值（99.60亿m3）的1.37倍,各作物水足迹变化不同,间接反映地区农业种植结构的改变。（4）京津冀水足迹总量提高2.45倍,耕地总量下降20.59%,水土匹配系数变...     

Determinants of efficiency of vegetable production in smallholder farms: The case of Ethiopia

Improving production efficiency remains as a plausible means of increasing productivity when resource reallocation, and the creation and adoption of new technologies are limited. Technical, allocative and economic efficiencies are derived from a sample of smallholder vegetable farmers in Ethiopia using parametric and non-parametric methods. The results reveal that the two methods yield similar estimates and the existence of substantial inefficiencies in production as well as efficiency differentials among farmers. The analysis of the determinants of efficiency of vegetable production using regression models show that low asset ownership, illiteracy, large family size, inadequate extension contacts, small farm size, age, low off/non-farm income and high consumer spending are the major socio-economic factors causing inefficiency of vegetable production in the study areas. A comparison of the market-driven (vegetables) with the whole-farm (crops and livestock) production efficiency indicates that lower economic efficiency scores for the former might be related to the limited access to capital markets, high consumer spending, and large family size.     

A GRAPHICAL ILLUSTRATION OF THE DULOY PARADOX

As a guide to the reorganisation of resources, the MVP /MFC comparison can result in the adjustment of resources to new levels which are actually further away from their optimal levels than their original values. Duloy illustrated this paradox mathematically in the context of fitted agricultural production functions in a paper published in 1959. His result is of considerable importance to agricultural micro-economists; however, it is not easy to teach to students of poor mathematical background. The need to be able to teach in literary form the Duloy Paradox–that increasing the application of a factor with a relatively high MVP can result in a movement away from the optimum input-mix–led to the following analysis.     

矿权性质及其市场制度

矿权市场在本质上属于要素市场 ,但在形式和部分功能上与商品市场有相通之处。矿权是用益物权 ,不是“经营权” ,也不是“知识产权”。生产要素有现成存在的 ,有需要通过特定生产过程才能形成或使用的 ,土地属于前者 ,矿产资源大部分属于后者。自然资源能做到清楚分割并实现排他性占有的 ,宜实行用益物权制度 ;做不到的 ,宜实行行政许可制度。土地一级市场最重要 ,大部分矿产资源二级市场最重要     

Irrigation production functions with water-capital substitution

The dynamics of biomass growth implies that the yield of irrigated crops depends, in addition to the total amount of water applied, on irrigation scheduling during the growing period. Advanced irrigation technologies relax constraints on irrigation rates and timing, allowing us to better adjust irrigation scheduling to the varying needs of the plants along the growing period. Irrigation production functions, then, should include capital (or expenditures on irrigation equipment) in addition to aggregate water. We derive such functions and study their water-capital substitution properties. Implications for water demand and adoption of irrigation technologies are investigated. A numerical example illustrates these properties.     

On the Function Coefficient, Euler's Theorem, and Homogeneity in Production Theory

This paper makes three related points useful in teaching first-year graduate production theory. First, the local applicability of the classical function coefficient idea for short-run nonhomogeneous production technologies is shown for returns to scale, satisfaction of second-order and total conditions for profit maximization, and delineation of the economic region of production in factor space. Second, the general applicability of Euler's Theorem results to nonhomogeneous (variable-proportional-return) cases is developed. Lastly, it is shown that short-run, nonhomogeneous production/yield functions are fully consistent with long-run linear homogeneity.     

Separability in farm-household economics: an experiment with linear programming

The assumption of separability between farm-household production and consumption facilitates analysis, but entails several important restrictions. The implications of assuming separability are discussed here in relation to the modelling of a representative Tongan farm-household. Econometric estimation of household demand is coupled with a linear programming (LP) model of farm-household production. When analysing consumer demand, separable farm-household economics is undoubtedly preferable to ignoring the production/consumption linkages entirely. However, the restrictions which must be imposed on the production side of the separable model are such that a realistic LP solution is unlikely to be obtained. This is likely to be a major deterrent to adopting the separable approach for studies in which the main focus is on production rather than consumption.     

Decisions and tradable production quota when yield is uncertain

This article analyses optimal decisions under regulation by tradable agricultural production/marketing quotas when production is stochastic. For risk-neutral and risk-averse producers the fraction of planned production that is covered by quota is separable from input decisions when yield randomness is additive. The role of quota in protecting against the risk of production shortfall is investigated. A producer is shown to benefit from being allowed to treat as one all tranches of production quota under his control. Production decisions are invariant to this amalgamation. But when production randomness is additive normal, the qualitative impact of amalgamation on quota positions depends upon whether the ratio of rental price to the price difference that is being protected exceeds one half.     

陕西省农业灌溉水资源保障程度及空间差异分析

[目的]文章选取2016年陕西省各市区农业灌溉水资源相关数据,分析其对粮食生产的影响,进而计算出陕西省及其各市区农业灌溉水资源对粮食生产保障程度,最终总结其存在的空间差异,并提出差异化的解决措施,以保障陕西省粮食安全。[方法]选用农业灌溉水资源保障度分析模型,针对陕西省各市区的水资源供需情况、粮食种植结构及产量和农作物灌溉情况,对陕西省及其各市区的农业灌溉水资源保障程度进行计算,研究其空间差异性。[结果]陕西省农业灌溉水资源保障度为101.84%,基本上能满足农业灌溉用水需求,但已迫近水资源供给紧张的边缘。陕西省农业灌溉水资源保障度呈显著的空间差异,关中地区农业灌溉水资源保障度P为82.20%,农业灌溉水资源轻度缺乏,属于资源型缺水现象;陕北地区农业灌溉水资源保障P为112.38%,影响该地区农业生产发展;陕南地区农业灌溉水资源保障P为145.92%,农业灌溉水资源丰富,灌溉耕地能够得到用水保障。[结论]农业灌溉水资源对粮食生产具有重要的作用,陕西省农业灌溉用水资源存在较大的空间差异性,需要参考不同地区的农业灌溉水资源保障度数值,采取不同的节水策略,以保障粮食安全生产。     

ON THE COMPETITIVE FIRM UNDER PRODUCTION UNCERTAINTY*

Risky production functions which are commonly in use are shown to be very restrictive. In particular, such functions cannot describe technologies where inputs marginally reduce risk. A simple production function which avoids these restrictions is posited and alternative estimation procedures are discussed. Both maximum likelihood and multistage estimators are discussed.     

中国实施渔村社区管理初探

渔业资源是一种流动性的共有资源,渔业社区管理是政府和渔民群体共同承担渔业资源养护和利用的权利和责任的一种管理制度,其核心理念是对公共渔业资源的使用权应授予依赖其生存的渔民群体。本文通过阐述当前中国渔业管理中存在的问题,论证了开展渔村社区管理的必要性,并从经济、社会、文化、景观、生态、政策六个方面研究了影响中国渔村社区建设的主要因素。     

PRODUCTION RISK AND EFFICIENT ALLOCATION OF RESOURCES

Efficient allocation of resources has usually been couched in risk less terms, partly because statistical techniques did not exist for measuring the impact of varying levels of factors of production on risks associated with production. Now that such techniques are available, methods are required for determining efficient allocations. Such models, particularly those exploiting stochastic efficiency analysis, are illustrated here with respect to empirical risk-sensitive, farm-firm production functions.     

The State-Contingent Properties of Stochastic Production Functions

The state-contingent properties of the most frequently used representations of stochastic production in the agricultural-economics literature are examined. Particular attention is paid to the cases of multiplicative uncertainty, additive uncertainty, and the Just–Pope production function. State-contingent technologies and their associated cost functions are reviewed, and that theory is applied to the stochastic production function. A generalization of the Just–Pope technology that has desirable state-contingent characteristics is proposed. Cost functions based upon state-contingent technologies are compared with cost functions based on a parametrized distribution representation of production uncertainty.     

气候变化对粮食产量影响的研究方法综述

[目的]受气候变化的影响,全球粮食安全面临严峻挑战,及时准确地评估气候变化对粮食产量的影响是应对挑战、制定农业适应性对策的关键。相关研究已产生了不少方法,通过综述对方法进行分类,明晰各种方法的优缺点和适用性,以期扬长避短,促进研究方法的综合、发展与完善。[方法]利用文献法、归纳法和比较法,从方法的原理和应用、存在的问题、发展的趋势3个方面进行探讨。[结果]产量分解法可用于分析粮食产量及其构成要素与不同生育期气候变化的关系,实验比较法一般用于粮食产量对单个气候因子或若干气候因子变化的敏感性分析,生产函数法适用于在农业生产系统中分析气候变化对粮食产量影响的边际效应,气候生产潜力模型法侧重于农业生产环境发展评估,作物生长模型法便于结合气候情景预测未来气候变化对粮食产量的影响。在不同研究方向上得以运用的同时,各方法也暴露了一些问题:产量分解法的技术产量难以拟合,实验比较法的数据获取难、模型稳定性较差,生产函数法容易遗漏重要变量、函数构造困难,气候生产潜力模型法的结论难以验证,作物生长模型法参数标定难、模型应用存在尺度错位。[结论]研究方法将逐渐形成一套综合的气候—水文—作物—经济模型法,多源数据融合和多目标模式已经成为方法发展的驱动力。     

Comparative Efficiency of Family and Corporate Farms: Does Family Labour Matter?

We examine the comparative efficiency of family relative to corporate farms, using FADN data for the Czech Republic, Hungary, Romania and Spain. We estimate a non‐parametric non‐separable farm production function, and derive efficiency scores for both family and corporate farms. We decompose efficiency into two distinct sources – organisational differences and management capabilities. We find evidence for organisational efficiency gains from family farming, relative to corporate farming, and these appear to increase with family involvement. However, with regard to management capabilities, family farms do not compare so favourably. Furthermore, family involvement does not seem to have any systematic effect on the efficiency derived from management capabilities. Our findings suggest that further investigation of the way family farms employ and build management capabilities is needed to substantiate any ‘superiority’ claims.     

Effectiveness of agricultural water management technologies on rainfed cereals crop yield and runoff in semi-arid catchment: a meta-analysis

Multiple agricultural water management (AWM) technologies are being promoted worldwide in rainfed agro-ecological production systems, such as the Limpopo River Basin, to close the yield gap, enhance food security and reduce poverty, but evidences on yield gains and environmental impacts are varied. This paper conducts a review of the performance of AWM technologies against conventional farmer practices to produce adequate evidence on cereal yield and field runoff changes. With the interrogation of literature from 1980 to 2013 using seven AWM groupings, enough evidence was found that AWM technologies can deliver substantial benefits of increased crop yield and water productivity with reduced environmental impacts. Using random effects model, the standardized mean difference (SMD) of yield between AWM and control was 0.27, while SMD of water productivity was 0.46, indicating the effectiveness of the technologies (SMD?>?0). Subgroup analyses showed greatest yield responses on silty-clay-loam, clay-loam and sandy soils compared to clay and loam-sandy soils, and higher yield increase under low rainfall regime (200–500 mm) than under high rainfall regime (500–800 mm). Large yield change variations for different AWM technologies present a huge opportunity for meeting the existing yield gaps and enhancing coping capacity in dry years and under climate change.