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 DEMAND FOR DOMESTICALLY PRODUCED SAWN TIMBER: AN APPLICATION OF THE DIEWERT COST FUNCTION

The Australian demand for domestically-produced sawn timber is investigated by considering its major use — as an input into residential construction. Using a cost function approach, a system of equations is derived expressing quantities demanded in terms of relative prices. Cross-price elasticities are estimated and the falling input-output ratio of timber in residential construction is analysed by decomposing the change in this ratio into price, outputs and taste/technology effects. A major finding is that, while substitution of timber for other inputs has been encouraged through relative price movements, this effect has been more than offset by taste and technology trends away from timber usage.     

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 EFFECT OF FERTILISER ON RISK: A HETEROSCEDASTIC PRODUCTION FUNCTION WITH MEASURABLE STOCHASTIC INPUTS

The sources of production risk are many and diverse in nature. Estimating risk as a black box, without explicit recognition of its sources, can lead to inferior estimates of optimal inputs under risk aversion. In this paper, a method is presented for estimating production functions with measurable stochastic inputs and for generating the parameters of the probability distributions of yield for various environments and input levels. Based on this method, it appears that moderate risk aversion can account for a 6.7 per cent to 16.7 per cent reduction in nitrogen use (relative to the risk-neutral solution) for selected rice producing areas of the Philippines. Estimating optimal inputs without environment specific information about the sources of risk leads to large errors. This underscores the value of collecting information about the sources of risk and of exercising caution when such information is not available.     

ALTERNATIVE DEFINITIONS OF DEMAND FOR RECREATIONAL ANGLING IN NORTHERN IRELAND

The effects of three alternative definitions of demand on estimated parameters are explored in a travel-cost study of aggregate demand for recreational angling in Northern Ireland in 1988. Functions are estimated using individual visits and zonal visitation rates for the number of visits and the number of visitors as alternative demand definitions. The approach using individual visits was found to be the more satisfactory in statistical terms and in relation to estimates of user benefits when compared with a parallel contingency valuation study. It is judged to be the more appropriate approach where there is a well defined and quantifiable user group. However, the modelling of income and substitutes in the functions proved to be unsatisfactory, perhaps due to inadequate specification and measurement of these variables.     

A PLANTING FUNCTION FOR PRIVATE AFFORESTATION IN NORTHERN IRELAND

Due to food surpluses, farming throughout the EEC has been put under increasing pressure to diversify. In line with this general trend, the Forest Service of the Department of Agriculture in Northern Ireland has endeavoured to increase the acreage under private afforestation. A knowledge of the responsiveness of private plantation to changes in grant aid and the time-scale involved in the reallocation of land towards afforestation is essential. This paper constructs a planting function, based on distributed lag structures, for private afforestation projects in Northern Ireland in an attempt to provide the relevant information.     

SUPPLY RESPONSE IN THE AUSTRALIAN SHEEP INDUSTRY: A PROFIT FUNCTION APPROACH*

Profit function models for the three major regions in which the Australian sheep industry operates are specified and estimated. The supply response elasticity estimates are made using a normalised quadratic functional form and time series cross-sectional data. Elasticity estimates, together with their confidence intervals, are presented for the pastoral, wheat-sheep and high rainfall zones. In general, the supply response elasticity estimates derived in this study are lower than those previously reported for studies in which little or no account has been taken of the multi-product nature of Australian agriculture.     

A SYSTEM APPROACH TO MODELLING SUPPLY EQUATIONS IN AGRICULTURE

A multinomial logit model is a useful approach in the study of the allocation of a fixed resource between alternative uses. Here a geometric mean form of the system is presented and a number of theoretical and empirical issues are explored. In particular, its performance is compared with the use of double logarithmic equations estimated separately. As an illustration of the methodology, an allocation model of UK cereals area is specified and estimated in both static and dynamic forms.     

A MODEL OF THE DISAGGREGATED DEMAND FOR MEAT IN AUSTRALIA

The focus of this study is the estimation of the Australian demand for meat between 1967 and 1990, employing a demand systems approach which uses the linear approximate, almost ideal demand system (LA/AIDS) model. Two demand systems are estimated by maximum likelihood methods, one for aggregate types of meat and one for disaggregated meat products. After correcting for serial correlation in the two demand systems, restrictions from utility theory are imposed and tested for their appropriateness. By using a new data set on the Australian retail price and consumption offresh pork, ham and bacon, the results from the disaggregated model provide the first estimates of the own-price, cross-price and expenditure elasticities for these commodities.     

DYNAMIC INTERRELATED DEMAND FUNCTIONS FOR FACTORS OF PRODUCTION AND THE AGGREGATE PRODUCTION FUNCTION IN UNITED KINGDOM AGRICULTURE

Taking the price situation as given in product and factor markets, a non-linear differential equation model of gross output, employment, capital accumulation, and gross input for united Kingdom agriculture is derived by incorporating internal adjustment cost functions into the representative decision-maker's objective function, and estimated using a discrete approximation. The results are consistent with efficient use of resources, but further incentives for capital investment and a greater exodus of labour could upset this. Adjustment costs as estimated account for 2.6 per cent of the value of output; those associated with net investment for 1.8 per cent, and those associated with employment and gross input for 0.57 and 0.23 per cent respectively.     

A REVIEW OF THREE RESEARCH PROGRAMS IN QUANTITATIVE MODELLING IN THE BUREAU OF AGRICULTURAL ECONOMICS*

Elements of three of the BAE's research programs in economic modelling of the rural sector, namely, the modelling of agricultural production systems, rural commodity markets and agriculture within a general equilibrium framework, are reviewed with emphasis on the use of such models in policy work. Suggestions are made for further modelling in these areas.     

民国年间冀中农户劳动生产率研究

农村经济的发展是整个社会现代化过程中最广阔、最深厚的基础,而农村生产者的劳动生产率则是农村经济发展的核心因素;单纯经济总量的增长不是最重要的,它往往被当代经济学家认为只有增长没有发展,或谓之为“没有发展的增长”。本文主要根据陈翰笙等老一辈学者30年代保定11村的实地调查资料和河北省统计局关于40年代同一地区的追踪调查资料,力求用实证研究的方法,从农民家庭的农副业生产与收入入手,试着计算出冀中地区农户的劳动生产率,包括工副业所占比例,进而从一个方面反映民国中后期北方农业生产力的发展水平。     

TESTING FOR CHANGES IN THE STRUCTURE OF THE DEMAND FOR MEAT IN AUSTRALIA

Quarterly data from 1962 to 1983 for beef, lamb, mutton, pig meat and poultry were used to test for constancy in the structure of meat demand in Australia. The cumulative sum, cumulative sum of squares and Farley-Hinich tests were applied to a range of models to ensure that any rejection of stability was not due to an inappropriate functional form or omitted dynamics. Little evidence was found of a marked swing away from consumption of any meat, with the exception of mutton. The results suggest that changes in prices and in total consumer expenditure are far more important than changes in tastes as determinants of meat consumption.     

WEAK SEPARABILITY AND A TEST FOR THE SPECIFICATION OF INCOME IN DEMAND MODELS WITH AN APPLICATION TO THE DEMAND FOR MEAT IN AUSTRALIA*

Most studies of the demand for meat in Australia have used some measure of total income or expenditure, but two recent studies have assumed weak separability of a meat group and used expenditure on the meat group instead. These specification differences are of interest to the extent that they affect the economic interpretation, goodness-of-fit, elasticity estimates, predictive performance or hypothesis tests in empirical demand equations. In this paper, non-nested hypothesis testing procedures are used to test the alternative specifications of the income variable and the hypothesis of separability. The results favour the use of the expenditure variable implied by separability but are mixed concerning whether separability holds.     

FOOD DEMAND IN SPAIN: AN APPLICATION OF THE ALMOST IDEAL SYSTEM

This paper provides an analysis of food demand in Spain for the period 1964–1989 estimating the Almost Ideal Demand System (AIDS) with annual time-series of food expenditures divided into six categories. A dynamic version of the model incorporating habit effects captures the behaviour of the Spanish food consumer over the period investigated. The theoretical hypotheses of homogeneity and symmetry are rejected, but the model provides plausible expenditure and price elasticities.