PROBABILISTIC COST EFFECTIVENESS IN AGRICULTURAL NONPOINT POLLUTION CONTROL

Conceptual weaknesses in the use of costs of average abatement as a measure of the cost effectiveness of agricultural nonpoint pollution control are examined. A probabilistic alternative is developed. The focus is on methods for evaluating whole-farm pollution control plans rather than individual practices. As a consequence, the analysis is presented in a chance-constrained activity analysis framework because activity procedures are a practical and well developed device for screening farm planes. Reliability of control is shown to be as important as reduction targets in designing farm plans for pollution control. Furthermore, broad-axe prescriptions of technology in the form of Best Management Practices may perform poorly with respect to cost effectiveness.Environmental Economics and Policy,

COST COMPARISONS OF ALTERNATIVE METHODS FOR PROCESSING RECYCLED WASTE NEWSPAPERS INTO FARM-ANIMAL BEDDING

The United States is facing a seemingly overwhelming problem of how to dispose of its solid waste. For disposal solutions to be viable, they must be environmentally sound and economically viable. Processing waste newspapers for farm-animal bedding offers a successful partial solution that meets both criteria. Centralized newspaper chopping is found to cost less than on-farm chopping. Both chopped and unchopped waste newspapers can be economically transported considerable distances. The use of waste newspapers for animal bedding is economically attractive at the farm level and can provide a partial solution to the solid-waste disposal problem.Environmental Economics and Policy, Livestock Production/Industries,

The roles and values of wild foods in agricultural systems

Almost every ecosystem has been amended so that plants and animals can be used as food, fibre, fodder, medicines, traps and weapons. Historically, wild plants and animals were sole dietary components for hunter–gatherer and forager cultures. Today, they remain key to many agricultural communities. The mean use of wild foods by agricultural and forager communities in 22 countries of Asia and Africa (36 studies) is 90–100 species per location. Aggregate country estimates can reach 300–800 species (e.g. India, Ethiopia, Kenya). The mean use of wild species is 120 per community for indigenous communities in both industrialized and developing countries. Many of these wild foods are actively managed, suggesting there is a false dichotomy around ideas of the agricultural and the wild: hunter–gatherers and foragers farm and manage their environments, and cultivators use many wild plants and animals. Yet, provision of and access to these sources of food may be declining as natural habitats come under increasing pressure from development, conservation-exclusions and agricultural expansion. Despite their value, wild foods are excluded from official statistics on economic values of natural resources. It is clear that wild plants and animals continue to form a significant proportion of the global food basket, and while a variety of social and ecological drivers are acting to reduce wild food use, their importance may be set to grow as pressures on agricultural productivity increase.</jats:p

Influenza Infectious Dose May Explain the High Mortality of the Second and Third Wave of 1918–1919 Influenza Pandemic

BACKGROUND: It is widely accepted that the shift in case-fatality rate between waves during the 1918 influenza pandemic was due to a genetic change in the virus. In animal models, the infectious dose of influenza A virus was associated to the severity of disease which lead us to propose a new hypothesis. We propose that the increase in the case-fatality rate can be explained by the dynamics of disease and by a dose-dependent response mediated by the number of simultaneous contacts a susceptible person has with infectious ones. METHODS: We used a compartment model with seasonality, waning of immunity and a Holling type II function, to model simultaneous contacts between a susceptible person and infectious ones. In the model, infected persons having mild or severe illness depend both on the proportion of infectious persons in the population and on the level of simultaneous contacts between a susceptible and infectious persons. We further allowed for a high or low rate of waning immunity and volunteer isolation at different times of the epidemic. RESULTS: In all scenarios, case-fatality rate was low during the first wave (Spring) due to a decrease in the effective reproduction number. The case-fatality rate in the second wave (Autumn) depended on the ratio between the number of severe cases to the number of mild cases since, for each 1000 mild infections only 4 deaths occurred whereas for 1000 severe infections there were 20 deaths. A third wave (late Winter) was dependent on the rate for waning immunity or on the introduction of new susceptible persons in the community. If a group of persons became voluntarily isolated and returned to the community some days latter, new waves occurred. For a fixed number of infected persons the overall case-fatality rate decreased as the number of waves increased. This is explained by the lower proportion of infectious individuals in each wave that prevented an increase in the number of severe infections and thus of the case-fatality rate. CONCLUSION: The increase on the proportion of infectious persons as a proxy for the increase of the infectious dose a susceptible person is exposed, as the epidemic develops, can explain the shift in case-fatality rate between waves during the 1918 influenza pandemic.TD acknowledges the support of the Faculdade de Ciencias e Tecnologia through grant PPCDT/AMB/55701/2004. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

A FARM-LEVEL ANALYSIS OF SOIL LOSS CONTROL: MODELING THE PROBABILISTIC NATURE OF ANNUAL SOIL LOSS

The Conservation Compliance provision of the Food Security Act of 1985 requires all farmers who farmed highly erodible land prior to the passage of the Act to have a locally approved conservation plan fully implemented by 1995 or lose eligibility for numerous farm programs. Soil loss estimates of various crop, tillage practices, and conservation practices, however, are stochastic in nature. A farm planning model is suggested that allows for stochastic soil loss estimates. The model is compared to other models used in farm level soil conservation studies. The model shows promise as a more acceptable tool in that the farm plans are more likely to be acceptable to the farmer

Farm Level Impacts of Cross Compliance Between Soil Conservation and Commodity Support and Insurance Programs

A proposal for integrating farm level conservation programs with other government farm programs is analyzed to determine the potential impacts on conservation incentives. Because many of the benefits of farm programs are due to resulting risk reduction, the impacts of cross compliance are analyzed in a quadratic risk programming framework

PROBABILISTIC COST EFFECTIVENESS IN AGRICULTURAL NONPOINT POLLUTION CONTROL

Conceptual weaknesses in the use of costs of average abatement as a measure of the cost effectiveness of agricultural nonpoint pollution control are examined. A probabilistic alternative is developed. The focus is on methods for evaluating whole-farm pollution control plans rather than individual practices. As a consequence, the analysis is presented in a chance-constrained activity analysis framework because activity procedures are a practical and well developed device for screening farm planes. Reliability of control is shown to be as important as reduction targets in designing farm plans for pollution control. Furthermore, broad-axe prescriptions of technology in the form of Best Management Practices may perform poorly with respect to cost effectiveness

REDUCING NUTRIENT APPLICATION RATES FOR WATER QUALITY PROTECTION IN INTENSIVE LIVESTOCK AREAS: POLICY IMPLICATIONS OF ALTERNATIVE PRODUCER BEHAVIOR

High rates of commercial fertilizer and animal manure application on cropland have been identified as an important cause of ground and surface water degradation in many areas of the country. Suggested remedies are often based on the idea that fertilization levels are economically irrational for the individual farmer. The received wisdom is that farmers could simultaneously improve their own economic well being and reduce the degradation of the ground and surface waters by fertilizing only to meet crop nutrient needs. Rather than assuming that farmers act irrationally, this study examines the fertilization problem on a mixed crop-livestock farm from the perspective of a risk-averse farmer coping with two key uncertainties: crop yield response to nitrogen applications and the nitrogen content of manure. The effects of fertilization decisions by such a farmer of various policy prescriptions for reducing surface and ground water pollution are examined. The results underscore the importance of understand producer behavior for the design of economically sound policy

A Dual Approach to Analysis of Dairy Production Decisions

A complete system of input and multiple output choice functions which by duality are consistent with the hypothesis of expected profit maximization are presented. Estimates are based the 1974 U.S.D.A. Cost of Production survey data and establish considerable price responsiveness of choices, a result which contradict's past econometric dairy supply studies

REDUCING NUTRIENT APPLICATION RATES FOR WATER QUALITY PROTECTION IN INTENSIVE LIVESTOCK AREAS: POLICY IMPLICATIONS OF ALTERNATIVE PRODUCER BEHAVIOR

High rates of commercial fertilizer and animal manure application on cropland have been identified as an important cause of ground and surface water degradation in many areas of the country. Suggested remedies are often based on the idea that fertilization levels are economically irrational for the individual farmer. The received wisdom is that farmers could simultaneously improve their own economic well being and reduce the degradation of the ground and surface waters by fertilizing only to meet crop nutrient needs. Rather than assuming that farmers act irrationally, this study examines the fertilization problem on a mixed crop-livestock farm from the perspective of a risk-averse farmer coping with two key uncertainties: crop yield response to nitrogen applications and the nitrogen content of manure. The effects of fertilization decisions by such a farmer of various policy prescriptions for reducing surface and ground water pollution are examined. The results underscore the importance of understand producer behavior for the design of economically sound policy.Environmental Economics and Policy, Livestock Production/Industries,