Irrigation areas in the Southern Murray-Darling Basin face a number of environmental and agricultural production problems. Two of the major on-farm environmental concerns for farmers are waterlogging and soil salinisation. Excess water use during irrigation can lead to salinisation and waterlogging by raising the level of the watertable through net recharge. This study examines three policy options that could be implemented to encourage increased water use efficiency, thereby reducing net recharge. The three policies are; a reduction in irrigation water allocations, an increase in the water price and the introduction of a tiered block water price scheme. The Coleambally Irrigation Area was chosen as a representative of irrigation areas in the Southern Murray-Darling Basin. A representative farm approach was used for modelling purposes. A farm level spreadsheet financial model and a linear programming model were developed to examine the effects of the policy options on farm financial performance and enterprise mix. A reduction in farm irrigation water allocation will provide a strong incentive to improve water use efficiency. However, the impact of this policy on financial performance is substantial. A flat water price increase saw no change in the land use patterns of the four representative farms though farm financial performance decreased significantly. Under a tiered block pricing structure 'inefficient' irrigators will be adversely affected financially by the introduction of a tiered pricing structure to a greater extent than under a flat price increase. The linear programming analysis suggests that the tiered pricing structure specified will provide a greater incentive for farmers to change enterprise mix to water efficient crops than a flat price increase. The results indicate that tiered block pricing for irrigation water has the potential to address the environmental problems of irrigation areas in the Southern Murray Darling Basin. Tiered block pricing provides a direct and ongoing incentive to continuously improve irrigation water use efficiency.

The objective of this study was to develop an appropriate analytical model for identifying an efficient level of exploitation of the inland fishery resource in South Sumatra, Indonesia. This study involved the evaluation of the existing status of fish stock and assessment of various possible policies for the fishery. The main problem for the inland fishery in South Sumatra is the tendency for the resource to be over-fished, which has been well recognised as shown by some overall indicators, such as virtual disappearance of certain important species and continuous reduction in the size of harvested fish. These problems indicate that proper management is required. This was approached by formulating an analytical framework which includes biological, economic and social aspects of the fishery. Using the biological surplus production model, a bioeconomic model for the inland fishery was developed. Based on the models of Gordon-Schaefer, Gordon-Fox and Copes, supply models for the fishery were estimated. Demand for freshwater fish in the region was assumed to be perfectly elastic. Primary data were used to describe recent cost of fishing effort. Secondary data, combined with results of analysis of primary data, were used to derive a supply function for the fishery. Given available data, and in order to satisfy the requirements for applying the selected model, different types of fishing gear were standardised into a single fishing unit and mixed species of harvested fish were treated as an aggregated fish stock.

This study is an attempt to explain the performance of the agricultural sector in Kenya by analysing the effects of the macro environment created by external shocks and the various policies that the Kenyan government may have used to address these shocks. A CGE model for the Kenyan economy is developed. The model is used to simulate two external shocks that affected Kenya in the 1970s as a result of the first oil-crisis and the coffee-boom and to evaluate the implications of actual and alternative economic policies in response to these external shocks, on the performance of the agricultural sector. The analyses of the terms of trade shocks indicate that the economy was quite vulnerable to external shocks. Results also indicated that the export boom contributed in a positive way towards ameliorating the negative effects that the Kenyan economy was facing as a result of the oil-price shock. However, contrary to expectations, rural households involved in agricultural production did not experience significantly larger increases in nominal incomes than their urban counterparts.

Continuing income growth and the development of the Chinese economy during the 1990s and the expectation that it will continue to the year 2000 are likely to produce a considerable change in Chinese food consumption patterns which are moving from a staple starchy food diet to one that includes high protein livestock products. Given an increase in demand and the possibility of a constrained domestic supply, demand for red meat may not be met in China. The present study is designed to examine this possibility. Changes in demand and consumption for red meat are explained by changes in prices and income within a complete demand system. Panel data from 1979 to 1992 are used to study to determine the demand relationships for pork, beef and mutton in China. The SUR technique was adopted as an appropriate least square estimator of the Double Logarithm model of retail demand for red meat and the Slutsky symmetry restrictions were imposed. Projections on demand for red meat between 1993 and 2000 are undertaken using a standard method.