282 research outputs found
Readdressing the Fertilizer Problem
The production literature has shown that inputs such as fertilizer can be defined as risk-increasing. However, farmers also consistently overapply nitrogen. A model of optimal input use under uncertainty is used to address this paradox. Using experimental data, a stochastic production relationship between yield and soil nitrate is estimated. Numerical results show that input uncertainty may cause farmers to overapply nitrogen. Survey data suggest that farmers are risk averse, but prefer small chances of high yields compared to small chances of crop failures when expected yields are equivalent. Furthermore, yield risk and yield variability are not equivalent.corn, nitrogen fertilizer, risk-increasing, yield risk, Crop Production/Industries,
Evaluating Yield Models for Crop Insurance Rating
Generated crop insurance rates depend critically on the distributional assumptions of the underlying crop yield loss model. Using farm level corn yield data from 1972-2008, we revisit the problem of examining in-sample goodness-of-fit measures across a set of flexible parametric, semi-parametric, and non-parametric distributions. Simulations are also conducted to investigate the out-of-sample efficiency properties of several competing distributions. The results indicate that more parameterized distributional forms fit the data better in-sample due to the fact that they have more parameters, but are generally less efficient out-of-sample–and in some cases more biased–than more parsimonious forms which also fit the data adequately, such as the Weibull. The results highlight the relative advantages of alternative distributions in terms of the bias-efficiency tradeoff in both in- and out-of-sample frameworks.Yield distributions, Crop Insurance, Weibull Distribution, Beta Distribution, Mixture Distribution, Out-of-Sample Efficiency, Goodness-of-Fit, Insurance Rating Efficiency, Farm Management, Financial Economics, Land Economics/Use,
Trials and Tribulations of Protecting Children from Environmental Hazards
Society is increasingly aware of the profound impact that the environment has on children’s health. Not surprisingly, there is increasing public scrutiny about children’s exposures to environmental hazards, especially for disadvantaged children. These trends underscore the ethical imperative to develop a framework to protect children from environmental hazards. Such a framework must include regulations to test new chemicals and other potential hazards before they are marketed, a strategy to conduct research necessary to protect children from persistent hazards that are widely dispersed in their environment, stronger regulatory mechanisms to eliminate human exposures to recognized or suspected toxicants, and guidelines about the ethical conduct of research and the role of experimental trials that test the efficacy and safety of interventions to prevent or ameliorate children’s exposure to persistent toxicants or hazards that are widely dispersed in their environment
Two Capture Techniques For American White Pelicans and Great Blue Herons
We describe two techniques for capturing American White Pelicans (Pelecanus erythrorhynchos), Great Blue Herons (Ardea herodias), and other large wading birds in aquatic habitats. One technique involved using #3 padded jaw leghold traps modified by replacing both factory coil springs with weaker #1.5 coil springs, to reduce the closing force of the jaws, and replacing the factory chain with a length of aircraft cable and an elastic shock cord, to minimize injury caused by lunging. The second technique involved using a modified portable rocket net that can be set in shallow water. We captured 142 American White Pelicans and 23 Great Blue Herons using these two techniques. We describe situations best suited for the optimum use of each technique. Both methods are humane and cost, labor, and time efficient
Insuring Uncertainty in Value-Added Agriculture: Ethanol Production
A wide variety of insurance products is available to agricultural producers to insure against yield or price risks in the markets for the raw commodities they produce. Value-added enterprises, such as ethanol production, have been expanding over the last decade. This paper outlines the development of an insurance product aimed at corn producers who are members of an ethanol production cooperative. The product has the potential to provide these producers with a new and useful risk management tool to insure against price risks in the markets for corn, distillers dried grains with solubles (DDGS), ethanol, and natural gas. Monte Carlo analysis is used to develop fair premiums at various coverage levels. A historical correlation structure is imposed on the simulated price data using a method proposed by Iman and Conover (1982), which maintains the marginal distributions of the variables. Historical analysis is carried out to examine how the product would have performed had it been offered over the last decade. The product is shown to perform as intended, paying indemnities in years of extreme price volatility
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