THE DEMAND FOR INPUTS AND THE AGGREGATE SUPPLY FUNCTION FOR AGRICULTURE*

This paper presents a theoretical derivation of aggregate supply elasticities from the relevant input demand elasticities. By way of illustration, an estimate of the aggregate supply elasticity with respect to product price for United Kingdom agriculture is calculated. In addition, the paper investigates the supply function that is implied by input demand functions which contain a geometrically declining lag distribution. The paper concludes by suggesting that the indirect estimation of aggregate supply elasticities may well be preferable to direct estimation of the elasticities.     

AGGREGATE DEMAND FOR NITROGENOUS FERTILISER IN THE UNITED KINGDOM: ANOTHER LOOK*

Economic theory must be subjected to continuous empirical testing and verification. Consequently any econometric model proposed may be re-tested and modified in the light of imporved data availability and additional observations generated by the real world. This paper re-examines U.D. aggregate demand for nitrogen: after otaining a meaningful data series for the price of nitrogen it is found that earlier functions fitted do not now stand up to the passage of time. Alternarte hypotheses are then put forward.     

THE DEMAND FOR FERTILISER IN THE UNITED KINGDOM

Among the policy alternatives for limiting fertiliser use, a tax on chemical fertiliser is administratively the easiest option. Its efficacy depends partly on the responsiveness of fertiliser demand to price changes. This paper reviews the empirical methodologies available for estimating the price elasticity of a derived demand and presents the results of several econometric models. The econometric analysis shows that the response of UK fertiliser demand to own-price changes is greater than has been assumed on the basis of programming studies of arable farms. This result establishes a necessary but not a sufficient condition for an effective fertiliser tax. The full impact of a fertiliser tax over the longer term depends on the extent to which technical change is driven by trends in relative prices.     

THE ECONOMIC SURPLUS OF AGRICULTURE IN THE UNITED KINGDOM*

The economic surplus of an industry is defined as the difference between its real product, and the real income accruing to it. The surplus from U.K. agriculture measured at 1964/65–66/67 prices is estimated to have risen by about 20 million per year in recent years. The absorption of this surplus by other sectors is identified and an approximate indication is given of the equivalent surpluses and deficits of other industry groups. The economic surplus from agriculture is transferred principally through changes in relative prices, the necessity of which tends to create an unavoidable minimum rate of inflation. There is an international equivalent of these transfers of real income through price changes, but without the institutional constraints on the market which in the domestic economy preserve some measure of equity in the distribution of income.     

THE DEVELOPING FRAMEWORK FOR THE ECONOMIC EVALUATION OF FORESTRY IN THE UNITED KINGDOM*

This paper evaluates the economic worth of forestry projects in the United Kingdom by using two different public sector investment appraisal criteria; the traditional discounted cash flows and the recently-established sum of discounted consumption flows. In the latter, in view of the intergenerational distribution aspect of government projects, the conventional rules are modified, enabling the decision-maker to treat all generations, present and future, in an equitable manner. Forestry is an excellent example to highlight the issue that many public sector investment projects re-distribute income between generations. Its long gestation periods make it obvious that there is more than one generation involved in the venture. In this analysis a one hectare plantation of Sitka spruce, class 20, is considered for a single 50-year rotation. Three different interest rates, 10 per cent test rate of discount, 5 per cent required rate of return, and 3 per cent forestry target rate are used under 4 different assumptions regarding the future price of timber.     

ESTIMATING THE DEMAND FOR WATER IN COMMERCIAL AGRICULTURE*

The foundation of the demand for water in agriculture is the water response functions of the various crops grown. As the productivity of water is largely determined by the lime at which a crop is irrigated, both intra-seasonal and seasonal demand schedules for water exist for the firm and so for the region. The efficient interregional allocation and pricing of water between users may be assessed using spatial equilibrium models. While a profit maximising objective may be valid for the firm, as the level of an analysis moves to the regional or the inter-regional complex, increasing attention must be paid to non-economic goals which must be incorporated within societies' objective. La demande ?eau dans ?agriculture se base sur les fonctions du besoin ?eau des récolies différents. Tandis que la productivité de ?eau est déterminé en grande parlie selon la saison pendant laquelle une récolle est irriguée, des programmes de demande intra-saisonnier et saisonnier pour ?eau existe pour ?exploitation, ainsi que pour la région. ?allocation efficace au niveau inter-régional et ?établissement ?un prix pour ?eau parmi les utilisateurs peuvent être évalués en se servant de modèles ?equilibre spatial. Tandis qu'un but de maximisation de profit peut être valide pour ?exploitation. au moment ou une analyse comprend le systems régional ou inter-regional, il faut aussi considérer les buts non-économiques qui doivent etre incorporés dans les objectifs sociaux.     

SOME FEATURES OF FARM INCOME AND STRUCTURE VARIATIONS IN REGIONS OF THE UNITED KINGDOM

Farm income trends and developments in farm structure have varied within the UK in the last decade. While Wales and Northern Ireland have similarities in form structure, agricultural production has risen to a much smaller extent, and farmers have suffered more severe net income reductions, in Scotland and Northern Ireland than in England and Wales. The net incomes of Cropping farms rose faster and, in England, have remained much higher than those of Dairy or Livestock farms. Large numbers of small farm businesses depend on beef cattle and sheep production and have limited development prospects. As most of their occupiers are unlikely to find other employment, structural problems will persist and policy adjustments are suggested to enable agriculture to contribute more to the economy in remote and depressed localities.     

THE PROBLEM OF THE SIZE OF THE MILK INDUSTRY IN THE UNITED KINGDOM

The Paper seeks first of all to examine statistically the “desirable size” of milk production in the U. K. under the policy laid down by Government of confining the industry to a narrowly defined liquid market. A basis analysis of trends and seasonality in monthly milk output is presented demonstrating the changes in seasonality over the years and its irregular variations. An analysis of variance of liquid sales and total output between weeks in the trough months forms the basis for calculating liquid trough requirements over and above average daily sales. From the trough requirement an annual requirement is calculated from the trend analysis suggesting a need for 2,285-2,416 m. g. to satisfy the market in all circumstances. Finally, certain major assumptions of the analysis which themselves are considered topics for further research are spelt out and some consideration given to the concept of the desirable size of industry itself     

中国柑橘供求弹性与生产波动影响因素实证研究

柑橘较高的替代性和较长生产周期,致使柑橘价格波动较大,影响柑橘生产的稳定性。该文首先 依据供求弹性理论,采用那维拉模型,构建柑橘供给反应函数和需求反应函数;其次,以1998～2011年为 样本期,测度了柑橘长期供给弹性和需求弹性,厘清了影响柑橘供给和需求变动的主要因素。结果表明: 柑橘当期种植面积、当期单产水平对柑橘供给有显著正向影响,滞后两期价格和滞后一期产量有较显著负 向影响;滞后两期产量对当期柑橘需求正向影响显著,当期加工能力和柑橘滞后两期价格具有正向影响。 研究结论:柑橘长期供给弹性（0.9）大于其需求弹性（0.14）、柑橘出口和企业加工总量以及5年的生产 周期是影响中国柑橘生产波动的主要因素;中国柑橘市场形似发散型蛛网,价格波动导致生产不稳定趋势 加剧。因此,为维持柑橘生产的稳定性,需要适度控制种植规模,调整品种结构,扩大柑橘出口规模,提 高柑橘产品的精加工和深加工的能力。     

美国农业遥感技术应用状况概述

介绍了遥感技术在美国窕作物估产中的应用现状,研究现状,以及美国农业部资源保护局的机构和职能设置,最后提出遥感技术在我国农业上应用的建议。     

分析预测·近年来我国稻米需求和生产情况

水稻是我国播种面积最大、总产最多、单产最高的粮食品种,在粮食生产和消费中历来处于主导地位。在过去30年中,水稻面积占我国粮食总面积的30%左右,稻谷产量占粮食总产量的40%左右,占谷物总产量的45%左右,占商品粮的50%左右。我国是世界上的水稻生产大国,稻谷面积居世界第二位、总产居第一位、单产居第十位。自1980年以来,我国水稻种植面积约占全球的23%,稻谷产量占全球的30%以上。可以说,稳定了水稻的生产,在很大程度上就稳定了我国的粮食供给;发展了水稻产业,就极大地发展了我国粮食产业。我国稻米消费和需求情况西方国家以小麦消费为主,…     

THE DEVELOPING FRAMEWORK FOR THE ECONOMIC EVALUATION OF FORESTRY IN THE UNITED KINGDOM — A COMMENT

The application of Kula's sum of discounted consumption flows method to forestry investment gives a more favourable result than NPV, but leads to some curious consequences. In particular, the immediate future generation may not be provided with a timber resource by the present generation, while being expected to provide such a resource for its own successors. The method does not in fact treat future generations equitably: downward revision of the social discount rate, possibly to zero, is a better means of achieving this objective.     

对兴安盟农业资源开发利用的建议

农业经济是兴安盟经济发展的基础,通过对全盟复建20年来的耕地、林地、草地的数量、质量变化,农业气候因素及农业生态环境的变化分析,阐明农业资源开发利用中存在的问题,并用可持续发展的观点提出了全盟退耕33．3万hm^2的科学依据。农业产业结构是建立在农业资源开发利用的基础之上,农业产业结构的变化也反映了资源开发的变化,20年来农业产业结构发生显著变化,农业生产取得巨大成就,文中根据全盟农业资源分布的时空差异,以实施西部大开发和加入世界贸易组织为机遇,进一步确定了全盟农业资源开发区域划分,提出了粮豆主产区、城镇郊区、生态脆弱区、牧区和林区等5个区域,指出了各个区域的发展方向和重点,为提高农业结构调整的水平和发展持续农业奠定了基础。