UTILITY FUNCTIONS AND DEMAND STRUCTURE*

The purpose of this paper is to review the demand structures implied by several common utility specifications. After a review of the Hicks-Allen measures of the demand structure, four utility functions are examined including the Cobb-Douglas, CES, and Mukerji functions. The results indicate that the most popular utility specifications provide patterns of demand parameters which do not conform to those made in estimation of commodity demand functions L'objet de cet papier est passer en revue des structures commandes de quelques caractéristique de ?utilité. Après un revoir de la proposition du Hicks et Allen du structure commandes, quatre fonctions pour ?utililé sonl examiné. Ils renfermes les fonclions du Cobb-Douglas, CES, et Mukerji. Les résultats indiquent ce que les caractérisliques de, ?utilité le plus populaire pouvoissem les modèles les quels ne confor-mentpas à celles des fonctions des commandes pour les produils.     

RISK,UTILITY AND THE PALATABILTY OF EXTENSION ADVICE TO FARMER GROUPS

Using the results of an empirical study of farmers' utility functions, evidence is presented that risk plays a measurable role in farmer decision making. The extension implications of such risk influences are discussed with particular emphasis on the possible efficacy of using group utility functions as a basis for group recommendations.     

RISK PERCEPTION AND THE ANALYSIS OF RISK ATTITUDES*

Risk has long been recognised as an important feature of the environment facing farmers. In recent years the von Neumann-Morgenstern expected utility theory has been used to analyse decision making under risk. However, many people behave in a manner inconsistent with the expected utility theory. One widely suggested explanation is based on subjective probability distortion. A number of attempts to incorporate this phenomenon into utility theories have been made. In this paper, the problems of analysing subjective probability distortion are discussed. Evidence from a survey of farmers' risk attitudes undertaken in conjunction with the 1977 BAE Australian Agricultural and Grazing Industries Survey is analysed in the light of this discussion.     

STABILISATION AND RISK REDUCTION IN AUSTRALIAN AGRICULTURE*

Agricultural producers typically are faced with risk about the yields they will experience and the prices they will receive. Stabilisation schemes can spread risk and thereby reduce the risk faced by individual producers. The risk-reducing capacity of a scheme and the cost of risk reduction depend upon the design of the scheme. In particular, it is important to distinguish between risk and instability. A classification of scheme designs is presented to bring out the effects of various design types. Schemes for the wheat industry are given most attention.     

FARM SYNDICATION AND RISK SHARING: A CASE STUDY*

The effectiveness of fully integrated group farming as a means of permitting farmers to achieve economies by working together and to share risk is investigated using two case-study farms from the mid-north region of S.A. Linear programming is used to explore the scope for economies achievable through group farming. The results show that, by joint use of resources, total net farm income can be increased and average costs per unit value of output can be reduced. The risk-sharing advantages of group farming are examined using quadratic risk programming. A group farm plan is found that generates a risky income which, when shared between the two risk-averse farmers, allows both to increase their expected utilities. The group plan also generates a higher aggregate expected net farm income than with sole ownership.     

NONPOINT POLLUTION,WEEDS AND RISK

Nonpoint pollution from agricultural production continues to force regulators to rethink policies aimed at reducing input sources such as herbicides and fertilisers. This paper considers how a producer's choice of an input strategy defined by application rate or persistence affects input-use patterns, and consequently, nonpoint pollution. Working within an endogenous risk framework, we explore how input sets with herbicides defined either as self-insurance or self-protection are affected by increased risk of herbicide treatment failure. Our results suggest that increased risk will generally decrease both herbicide and fertiliser application rates, resulting in the use of less flexible and less persistent herbicides. In addition, a quantity constraint policy restricting the amount of herbicide applied will decrease the amount of fertiliser applied.     

CROSS-SUBSIDISATION OF RURAL AREAS VIA UTILITY PRICING POLICIES*

Public utilities which apply roughly uniform prices to all consumers often engage in cross-subsidisation — charging prices which are below cost for consumers in low population density areas but above cost for consumers in high density areas. The distributional and allocative implications of this practice are examined and it is concluded that some cross-subsidisation may be justifiable on welfare grounds even where no externalities exist. There is, however, little empirical evidence released by utilities to enable assessment of the efficiency of their practices. If nothing else, we highlight the need for greater public disclosure of pricing practices by public utilities.     

RISK ATTITUDE,PLANTING CONDITIONS AND THE VALUE OF SEASONAL FORECASTS TO A DRYLAND WHEAT GROWER*

The value of a seasonal forecasting system based on phases of the Southern Oscillation was estimated for a representative dryland wheat grower in the vicinity of Goondiwindi. In particular the effects on this estimate of risk attitude and planting conditions were examined. A recursive stochastic programming approach was used to identify the grower's utility-maximising action set in the event of each of the climate patterns over the period 1894-1991 recurring in the imminent season. The approach was repeated with and without use of the forecasts. The choices examined were, at planting, nitrogen application rate and cultivar and, later in the season, choices of proceeding with or abandoning each wheat activity. The value of the forecasting system was estimated as the maximum amount the grower could afford to pay for its use without expected utility being lowered relative to its non-use.     

PRODUCER RISK,PRODUCT COMPLEMENTARITY AND PRODUCT DIVERSIFICATION

In this paper, a model is presented of the product diversification problem which features both producer risk aversion and product complementarity as determinants of product diversification. Although both risk aversion and product complementarity are, in the absence of the other, incentives to diversity production, when the two are present their joint influence may create a disincentive to diversification. In particular, an increase in the value of product complementarity may result in reduced product diversification for a risk-averse producer.     

THE INTEGRATED USE OF SIMULATION AND STOCHASTIC PROGRAMMING FOR WHOLE FARM PLANNING UNDER RISK*

Methods of whole-farm planning under risk are briefly reviewed, noting especially associated operational problems. A planning problem relating to spatial diversification of beef production in the Clarence region of N.S.W. is investigated using a model comprising both simulation and linear programming components. It is concluded that such composite models are valuable for the analysis of sequential stochastic decision processes not presently amenable to solution by stochastic programming alone.     

ON THE NEGLECT OF DYNAMICS,RISK AND MARKET INSULATION IN THE ANALYSIS OF URUGUAY ROUND FOOD TRADE REFORMS*

The substantial investment in models of international food markets prior to and during the Uruguay Round of international trade negotiations has been a mixed blessing so far as the prospects for reform are concerned. At worst, results from these models have misled the negotiations because they have most often ignored a primary concern lending domestic political support to food market interventions, namely the avoidance of risks borne of dependence on international markets. In this paper the reasons for market insulating policies are reviewed and their links with protection elucidated. Some errors that have stemmed from the application of 'standard' but inappropriate models are noted. Finally, the implications of extending the standard method to include dynamic behaviour and market insulating policies are examined.     

RISK EVALUATION IN FARM PLANNING* A STATISTICAL APPROACH

Economic planning implies decision-making based on the comparison of alternative courses of action, viewed against a background (in the real world at any rate) of uncertainty and imperfect knowledge. Successful planning is thus heavily dependent on the reliability of prediction which lea & inevitably to the domain of probability theory and its application to planning models. In spite of the considerable attention given to the application of mathematical models in farm management research work in recent times⁽¹⁾ to⁽⁹⁾ and ⁽¹⁵⁾ there is stilla paucity of applied work with respect to evaluating the nature of risk associated with planning projects at the individual farm level. In addition, very little published data is available on either a regional or production-type basis that gives a clear understanding of the nature of probability distributions for planning variables. This paper formulates a simple model which can be used in practical planning exercises and also demonstrates that with a new generation of statistically-processed planning data the application of the classical concepts of probability to routine economic planning is both practicable and worthwhile.     

AGRICULTURAL ECONOMICS,INTERDEPENDENCE AND UNCERTAINTY*

Interdependence has always been central to economics but assumes pressing importance for agricultural economists as they deal with industrialising agricultures. Continued unresolvable uncertainties, when properly recognised, also add to the challenge of relevant work in agricultural economics. The related roles of interdependence and uncertainty are illustrated through examples from the progress of agricultural technology and enhancement of food security.     

景观生态风险信息系统的概念、方法和步骤

景观生态风险信息系统（LERIS）是将景观生态学理论和3S技术相结合进行风险分析的现代规划管理系统。它通过对自然景观、人文因素矣风险源的全面调查,将所需的各类信息进行方便快速的采集、处理和管理等,利用GIS对景观生态状况和潜在风险进行分析、模拟和预测,从而为管理部门的决策提供科学的依据。LERIS在资源和环境的管理和规划领域具有广阔的应用前景。结合实例介绍了景观生态风险信息系统概念、方法和步骤,以期引起国内同仁的进一步关注。     

ESTIMATION OF EFFECTIVE RISK REDUCION THROUGH IRRIGATION OF A PERENIAL CROP*

This paper outlines an approach to assessing the benefits from in vestment in the irrigation of tea stands in three areas of East Pakistan. Irrigation aflects both the establishment and productive life of the growing crop, and therefore the analysis includes a discounred assessment of the replacement decision, as well as an appraisal of the change in technology. Since the biological and weather eflects that determine annual and long-run productivity of the stand are stochastic variables, the evaluation is made using a simulation model in which these determinants are introduced as known discrete probabilities. Using this model an estimate may be made of rhe net gains to a tea estate of the risk reduction achieved by eliminating harmful crop moisture deficits.     

THE NATIONAL INTEREST,WESTMINSTER, AND PUBLIC CHOICE*

There has been increasing scrutiny of government policy decisions and advice in recent years. The supremacy of the national interest has been questioned and self interest theories explored. Administrative systems have been reformed, and the role of the Westminster model of government decision-making endlessly reviewed. Increased interest by economists in the policy process has created a new subject area in economics, namely, public choice theory. It places greater emphasis on individual choice and hence on the way political institutions meet society's needs. It provides a suitable framework for explaining political decision making and administrative processes. In this Address, New Zealand agricultural policies and processes in the last two decades are explored from this viewpoint and the applicability of the theory assessed.     

SIMULATED MARKETS,FARM STRUCTURE,AND AGRICULTURAL POLICIES*

In this investigation estimated relationships of resource markets for United States agriculture are used in a simulation model to study resource demand and farm income under three conditions: (a) those actually prevailing, including the historic mix of agricultural policies, (b) with technical change in agriculture only half the rate realized, and (c) with a free market. The results indicate that compared with “actual” conditions the environment of slow technical change would have modest effects in slowing the demand for farm machinery and the migration of labor from agriculture. It also would result in greater net farm income in the 1960's. A free market would be accompanied by increased investment in farm machinery and a greater exodus of family and hired labor from agriculture. It also would result in a smaller farm building investment and a considerable reduction of farm income. Since economic conditions are so similar in both countries, the implications of these findings are related to Canadian agriculture on the assumption the same model would show the same outcomes for Canada. Dans cette étude, des rapports estimés des marchés des ressources pour ?agriculture des Etats-Uns sont employés dans un modéle de simulation afin ?étudier la demande des ressources et le revenu agricol net sous trois conditions: (a) celle qui régne réellement, incluant le mélange historique de politiques agricoles; (b) celle qui ne montre le changement technique de ?agriculture qti à la moitié du train realise; et (c) celle qui profite ?un marché libre. Les résultats indiquent que ?enrironnement du changement technique modéré, quand il est compareé avec les conditions réelles, produirait des effets modestes en diminuant la demande pour des machines agricoles et en ralentissant ?exode de la main-?oeuvre de ?agriculture. En outre, cet environment aurait pour résultat un revenu agricole net plus fort dans les années de 1060 à 1970. Vne marché libre serait accompangne de placements augmentés dans les machines agricoles et ?un plus grand exode de la main ?oeuvre familiale et salariée de ?agriculture. Aussi, ceci aboutirait à un investissement moindre dans la construction rurale et à une réduction considérable du revenu agricole. Puisque les conditions économiques des deux pays sont si ressemblantes, les implications de ces conclusions sont rattachées à?agriculture cana-dienne en supposant que le même modéle montrerait les mêmes résultats pour le Canada.     

渔业风险的原因分析及防范对策

根据渔业的特点，结合渔业风险产生的原因，提出将渔业风险大致分为自然风险、市场风险、技术风险和管理风险四类，并针对渔业风险的类别，提出一系列有效措施，防范和降低渔业风险。