SUPPLY RESPONSE OF AUSTRALIAN WHEAT GROWERS

Alternative specifications of models of the supply response of Australian wheat growers and their economic implications are considered in terms of the existence and nature of production lags, and the choice between expected prices and expected gross returns as the preferred explanator of producers' response to changing economic conditions. The analysis indicates that there are lags which are due primarily to the difficulties and costs of rapid adjustment rather than to the time required to revise expectations. The statistical results were similar for the alternative specifications of gross margins and prices as the economic decision variables. However, the price elasticities derived using the gross margins specification were about a third of those using the prices specification. The gross margins specification yielded additional information in the form of yield and input cost elasticities.     

Spatial Complementarity of Forests and Farms: Accounting for Ecosystem Services

Our article considers the economic contributions of forest ecosystem services, using a case study from Flores, Indonesia, in which forest protection in upstream watersheds stabilize soil and hydrological flows in downstream farms. We focus on the demand for a weak complement to the ecosystem services—farm labor—and account for spatial dependence due to economic interactions, ecosystem processes, and data integration. The estimated models have theoretically expected properties across eight different specifications. We find strong evidence that forest ecosystem services provide economically substantive benefits to local people and that these services would be substantially undervalued if spatial dependence is ignored.     

MEASURING RESEARCH BENEFITS FROM A REDUCTION OF PALE,SOFT AND EXUDATIVE PORK IN AUSTRALIA

In this paper, a closed-economy model is developed for evaluating the size and the distribution of benefits from research that lowers the mean incidence of pork with pale, soft and exudative (PSE) syndrome. The major finding is that the Australian pig industry has the potential to derive gross research benefits of about A$7 million per year from a one percentage point reduction in the incidence of pork with PSE conditions. About 85 per cent of the total research benefits accrue to pork producers. The implication is that it is profitable for pork producers to invest large sums in order to reduce PSE syndrome in pork.     

中国生猪养殖场种养一体化综合效益评价研究基于8省的实地调研

目的 种养分离的农业发展方式对生态环境造成严重破坏,是不可持续的发展方式,为重构种养一体化农业循环链条,促进农业健康可持续发展,通过实地调研,分析了中国生猪养殖场种养一体化现状,并从经济效益、社会效益和生态效益方面确定了14项综合效益评价指标,从实证角度对种养一体化农业系统的综合效益进行评价。方法 文章综合运用层次分析法和熵值法测算综合效益评价指标的权重,利用线性加权求和的方法对生猪养殖场种养一体化综合效益进行评价。结果 研究发现：在评价指标的权重方面,生态效益与社会效益的权重已经高于经济效益权重,说明当下社会更加注重生态和社会效益的发展;种养一体化农业系统的综合效益值明显高于非种养一体化,小、中、大规模的生猪养殖场种养一体化综合效益值分别是非种养一体化的1.16、1.20和1.17倍;综合效益值随养殖规模扩大呈现出先增加后减小的趋势,且养殖规模为1 300头左右时综合效益值最高。结论 虽然种养一体化农业系统的综合效益高于专业化农业生产,但在生猪养殖场种养一体化中仍然存在种养失衡、种养协作微弱等问题,尚未达到系统最优化,因此从种养平衡、养分管理体系建设、提高沼气工程利用率和优化种植结构方面提出对策建议。     

A CROSS-COMMODITY APPRAISAL OF DEMAND-RAISING RESEARCH BENEFITS: PORK AND CHICKEN IN AUSTRALIA

A multi-commodity model is developed for evaluating the gains from research which raises the demand for a commodity, and applied to the pig and chicken industries in Australia. The major finding is that the gain to pork producers is larger, and the gain to consumers smaller, with a cross-commodity consideration than without. Bigger differences in results are observed with larger values of the cross-price elasticity between pork and chicken, and with a larger shift in demand for chicken. However, the aggregate benefits to the Australian pig industry are not significantly affected by price changes in the market for chicken. The implication of the analysis is that, by ignoring the cross-market feedback between commodities closely related in consumption, consumers (or taxpayers) of the commodity experiencing a rise in demand may bear a higher-than-optimal outlay on public research directed to increasing the demand for that commodity.     

石灰岩地区小水库除险加固工程的经济社会效益分析

简要介绍石灰岩地区小水库的特点、存在问题以及综合采用灌浆、复合土工膜覆盖和坡面复合式防渗等技术集成的加固方案。以江苏省徐州市石灰岩地区的5座小水库为例,参照相关规范分析水库工程取得的社会效益和生态效益,从防洪、灌溉和多种经营效益等方面详细计算了病险水库除险加固工程的经济效益。根据工程的实际资料,采用国民经济评价方法,对5座小水库除险加固工程的经济内部收益率、经济效益费用比、经济净现值3项指标进行了分析。结果表明,该工程在经济上是合理的,具有显著的社会效益和环境生态效益。     

An open-access method for targeting revegetation based on potential for emissions reduction,carbon sequestration and opportunity cost

We propose a simple heuristic that uses open-access models and government data on agricultural activities to estimate total carbon emissions from agriculture, the gross carbon benefit and the opportunity cost per tonne CO₂-e from revegetating to environmental plantings or plantation forestry. We test this across ten areas of mixed land-use that represent diverse Australian agricultural systems along a rainfall transect. The local value of agricultural production was obtained from government statistics and used to estimate the current economic opportunity cost of converting cleared agricultural land to mixed environmental plantings for carbon sequestration. Gross carbon benefit from revegetation was closely related to current agricultural use, as was financial opportunity cost. These were not related simply to site productivity potential or rainfall. The proportion of land cleared for agriculture that would need to be re-vegetated to achieve a localised zero-carbon land-use scenario was calculated by the ratio of current agricultural emissions to gross carbon benefit from revegetation; this ranged from 13% to 66% for groups of agricultural industries across Australian rainfall transects. While the heuristic does not capture the detail of models built specifically for local research questions it does provide a different lens on the questions policy makers and land managers may ask about the costs and benefits of revegetating agricultural land, and provides open-access methods to guide them.     

The importance of seasonal variability and tactical responses to risk on estimating the economic benefits of integrated weed management

Seasonal variability is an important source of risk faced by farmers and, regardless of an individual's attitude to risk, there are options to tactically adjust production strategies as the outcomes of risk become known. The objective of this article is to measure the economic benefits of alternative approaches to managing weeds, one of the most serious production problems in Australian cropping systems. A bioeconomic model that combines weed biology, crop growth and economics is developed to value the effects of seasonal variability and the role of tactical responses and sequential decision making in determining an optimal integrated weed management strategy. This shows that there are substantial differences in the measured long‐term benefits from deterministic and stochastic simulations. It is concluded that, for research evaluation of technologies that involve complex biological and dynamic systems, ignoring the impacts of seasonal variability, responses to risk and sequential decision making can lead to an incorrect estimate of the economic benefits of a technology. In this case study of optimal weed management strategies in Australia, the size of the error is high.     

Dairy productivity and climatic conditions: econometric evidence from South‐eastern United States

Climate change and food security have become critical issues in the agricultural policy agenda. Although global warming is expected to increase both the frequency and severity of heat stress on dairy cattle, there are very few economic studies focusing on this issue. This paper contributes to the literature by integrating the frontier methodology, commonly used in applied production economics, with heat stress indexes used by animal scientists but largely ignored by economists. Our econometric models are useful to quantify gross benefits expected from adaptation to climatic conditions represented by the Temperature Humidity Index (THI) and alternatively by the Equivalent Temperature Index (ETI). Stochastic production frontier analysis is used to measure technical efficiency for an unbalanced panel of 103 dairy farms located in Florida and Georgia. Five alternative model specifications are evaluated. The results reveal that both THI and ETI have a significant nonlinear negative effect on milk production. The climatic indexes when incorporated in the frontier specification absorb some of the output shortfall that otherwise would be attributable to inefficiency. The results indicate that using fans combined with sprinklers is an effective adaptation to offset output losses stemming from heat stress conditions.     

南美白对虾两种养殖模式下的经济效益比较分析

论文比较分析了南美白对虾高位池精养和土池生态养殖两种养殖模式的经济效益。结果表明：高位池精养模式的产量、产值、净利润在绝对值上分别比土池微生态养殖模式高306．44斤／亩、8860．29元／亩、2553．27元／亩,前者经济效益较高;两种养殖模式成本利润率分别为31．39％和26．02％,高位池精养模式提高经济效益主要依靠的是高成本投入,需提高成本利用效率。论文还对影响南美白对虾经济效益的原因进行分析,其中基础设施、总成本和人力成本、产品规格、养殖周期、技术支持和管理水平是造成经济效益差异的主要原因,从而进一步提出提高南美白对虾养殖经济效益的措施。     

The economic benefits of rabbit control in Australian temperate pastures by the introduction of rabbit haemorrhagic disease

The European rabbit is present in most Australian environments and causes economic loss in agricultural systems by reducing production and imposing control costs on producers and governments. Research into rabbit control has recognised the need for reliable benefit‐cost analysis to justify inputs into rabbit management. This paper provides estimates of the costs of rabbits in Australian temperate pasture systems and of the long‐term benefits of reducing rabbits by the introduction of rabbit haemorrhagic disease (RHD). Rabbits impose annual costs on wool producers in the temperate pasture areas of between 7.1 and 38.7 million Australian dollars (mA$) depending on their density. Controlling rabbits by RHD has the potential to generate substantial long‐term economic benefits by reducing grazing competition with sheep. Reducing rabbit costs by 25% generated 15‐year net present values (NPVs) between 18.4 and 97.3 mA$ at various pre‐RHD rabbit densities. A 50% reduction in rabbit costs increased the total NPVs between 36.9 and 202.4 mA$, virtually all of which was captured by temperate area wool producers. The corresponding benefit‐cost ratios were between 2.9:1 and 16.2:1 for a 25% rabbit reduction and 5.9:1 and32.4:l for a 50% reduction, where the total costs of the RHD program in the temperate pasture areas were incurred by the wool industry. The analysis provides guidelines for the economic evaluation of other pest problems in agricultural production systems.     

A NOTE ON THE PIG CYCLE IN AUSTRALIA

Spectral analysis is used to test hypotheses relating to regular four-year cycles in the Australian pig industry. The data point to the existence of annual cycles in production, slaughterings and prices, but four-year cycles are only evident in pig prices. Relationships between these series are also examined by cross-spectral analysis     

Assessing forest management strategies using a contingent valuation approach and advanced visualisation techniques: A Portuguese case study

The assessment of alternative forest management strategies should account not only for the private benefits to forest landowners but also for the ecological, environmental and economic benefits valued by society. There are a number of empirical valuation methods that may contribute to that assessment. These methods involve several steps: data acquisition, model specification and estimation. In this paper, this approach is illustrated in the context of a survey regarding alternative management strategies for a forest area in Central Portugal by implementing a contingent valuation experiment where an advanced landscape visualisation technique is employed to generate the visual information conveyed in the valuation scenarios. Several econometric model specifications are considered as well as alternative approaches to handle zero willingness to pay values and protest responses. The results obtained suggest the potential of the proposed approach for an effective comparison of alternative forest management strategies.     

利用蓄水设施开发淤地坝水资源初探

介绍蓄水设施的布局与种类规格的选择、蓄水设施关键构件的设计、蓄水设施运行、管理、淤地坝水资源的高效利用、淤地坝蓄水设施经济效益等有关要点，提出在淤地坝内建蓄水设施是开发淤地坝水资源的一条有效途径的观点。     

Measuring market integration in the presence of transaction costs–a threshold vector error correction approach

Applied econometric analyses of market integration based on price data alone have been criticised because they neglect the role of transaction costs. To meet this objection, threshold vector error correction models are used. Threshold models can account for the effects of transaction costs in price transmission without directly relying upon information about these costs, which are often unavailable. It is argued that threshold models that are based on two thresholds provide results that are economically more intuitive than those obtained from one-threshold models. However, to this point no adequate econometric test is available for threshold significance in a two-threshold model; such tests are only available for the one-threshold model. In this paper a restricted two-threshold model is developed in which the significance of the thresholds can be tested. This model is therefore amenable to economic interpretation and statistical inference. The model is used to estimate market integration in the European pig market.     

THE DETERMINATION OF OPTIMAL RATIONS FOR PIGS FED SEPARATED MILK AND GRAIN*

This paper demonstrates a procedure for determining economically optimal rations which avoids problems that arise in conventional analysis of experimental results. It consists of maximising a suitably constrained profit per unit time objective function, itself formed from functions obtained from pig fattening experiments under special Australian conditions. The relevant functions-for consumption of milk and wheat, time to slaughter and percentage lean meatare first demonstrated, followed by a brief discussion of results obtained. Specifcally, it is noted that optimal diets differ according to whether the criterion adopted is profit per pig or profit per pig per week, that dairy farmers fattening pigs should feed substantial quantities of grain, and that the optimal diets are very stable to changing prices. More generally, the procedure avoids the statistical difficulties of conventional analysis of experiments arising from the estimation of weight-gain functions based on actual quantities of food consumed.     

THE IMPACT OF FARM AND PROCESSING RESEARCH ON THE AUSTRALIAN WOOL INDUSTRY*

An equilibrium displacement model of the world wool top industry is used to estimate the returns to the Australian wool industry from productivity improvements in farm production, in top making and in textile manufacturing. The returns to the industry from these different types of research and development are sensitive to the extent of substitution possibilities between Australian wool and other inputs used by the wool processing and textile industries but it appears that research resources have to be much more efficient in off-farm activities for the Australian wool industry to receive benefits similar to those from farm research activities.     

ECONOMIC GROWTH IN WESTERN AUSTRALIA

One measure of the economic activity generated by the primary sector is the extent to which the demand for its products is retained within the sector or is transmitted elsewhere. In this article an analysis is made of these inter-relationships between industries and between each industry and the trade sector, as they influence the rate and direction of economic growth in Western Australia. Two input-output models of the Western Australian economy are then used to examine structural changes implied in changes in input coefficients over time.     

Nonparametric measures of the impact of public research expenditures on Australian broadacre agriculture

Nonparametric methods are used to measure the impact of public research expenditures on Australian broadacre agriculture over the 1953–94 period. Results using both unrestricted and 30-year lagged specifications of the research impacts on productivity suggest that while certain aspects of the nonparametric multi-input/output technologies are quite robust to alternative specifications (in particular, the associated Malmquist total factor productivity indexes), other aspects are less stable (in particular, the indexes on input and, to a lesser extent, output biased technical change). Internal rates of return to research expenditures on Australian broadacre agriculture are estimated to be in the 12 per cent to 20 per cent range.     

Economic benefits of public investment in weed management: the case of vulpia in south-eastern Australia's temperate pasture areas

The present paper reports an economic evaluation of the long-term benefits to Australia of research by the Cooperative Research Centre for Weed Management Systems (CRC) into the improved management of vulpia , the major annual grass weed of temperate pastures in New South Wales and Victoria. Vulpia reduces livestock production by competition with more desirable pasture species, by the production of low quality feed at critical times of the grazing cycle, and by injury to animals. A 20-year stochastic benefit-cost analysis indicated that reducing the impacts of vulpia in these pastures produced a mean net present value of $A58.3 million and a mean benefit-cost ratio of 33:1. Temperate pasture zone wool producers would capture the largest shares of these benefits, Australian consumers would gain, but wool producers in the rest of Australia would suffer welfare losses from vulpia reductions in the temperate pasture zones.