CONCENTRATION IN AGRIBUSINESS

Industrial Organization,

The Economic Organization of U.S. Broiler Production

Broiler production in the United States is coordinated almost entirely through systems of production contracts, in which a grower’s compensation is based, in part, on how the grower’s performance compares with that of other growers. The industry is undergoing a gradual structural change as production shifts to larger broiler enterprises that provide larger shares of an operator’s household income. Larger enterprises require substantially larger investments in broiler housing, and new or retrofitted houses are also an important source of productivity growth in the industry. This report, based on a large and representative survey of broiler operations, describes the industry’s organization, housing features, contract design, fees and enterprise cost structures, and farm and household finances.broilers, chickens, production contracts, broiler grower financial performance, chicken housing, chicken litter, poultry, Farm Management, Production Economics,

Artificial intelligence approaches to software engineering

Artificial intelligence approaches to software engineering are examined. The software development life cycle is a sequence of not so well-defined phases. Improved techniques for developing systems have been formulated over the past 15 years, but pressure continues to attempt to reduce current costs. Software development technology seems to be standing still. The primary objective of the knowledge-based approach to software development presented in this paper is to avoid problem areas that lead to schedule slippages, cost overruns, or software products that fall short of their desired goals. Identifying and resolving software problems early, often in the phase in which they first occur, has been shown to contribute significantly to reducing risks in software development. Software development is not a mechanical process but a basic human activity. It requires clear thinking, work, and rework to be successful. The artificial intelligence approaches to software engineering presented support the software development life cycle through the use of software development techniques and methodologies in terms of changing current practices and methods. These should be replaced by better techniques that that improve the process of of software development and the quality of the resulting products. The software development process can be structured into well-defined steps, of which the interfaces are standardized, supported and checked by automated procedures that provide error detection, production of the documentation and ultimately support the actual design of complex programs

Evolutionary calculations of carbon dredge-up in helium envelope white dwarfs

We investigate the evolution of cooling helium atmosphere white dwarfs using a full evolutionary code, specifically developed for following the effects of element diffusion and gravitational settling on white dwarf cooling. The major difference between this work and previous work is that we use more recent opacity data from the OPAL project. Since, in general, these opacities are higher than those available ten years ago, at a given effective temperature, convection zones go deeper than in models with older opacity data. Thus convective dredge-up of observationally detectable carbon in helium atmosphere white dwarfs can occur for thicker helium layers than found by Pelletier et al (1986). We find that the range of observed C to He ratios in different DQ white dwarfs of similar effective temperature is well explained by a range of initial helium layer mass between $10^{-3}$ and $10^{-2} M_{\odot}$, in good agreement with stellar evolution theory, assuming a typical white dwarf mass of $0.6 M_{\odot}$. We also predict that oxygen will be present in DQ white dwarf atmospheres in detectable amounts if the helium layer mass is near the lower limit compatible with stellar evolution theory. Determination of the oxygen abundance has the potential of providing information on the profile of oxygen in the core and hence on the important $^{12}$C$(\alpha,\gamma)^{16}$O reaction rate.Comment: Accepted for publication in MNRAS, 8 pages, 6 figure

How do retail prices react to minimum wage increases?

Wages ; Prices

THE ENDOWMENT EFFECT AND WTA: A QUASI-EXPERIMENTAL TEST

This paper reports a test of the endowment effect in an economic analysis of localized air pollution. Regression techniques are used to test the significance of perceived property rights on household WTP for improved air quality versus WTA compensation to forgo an improvement in air quality. Our experiment contributes to the research into the WTP/WTA divergence by providing a new basis for supporting the existence of an endowment effect. Our results are in contrast to recent work by Shogren et al. which supports the substitution proposition of Hanemann while rejecting the endowment effect.Contingent valuation, Endowment effect, Property rights, Substitution effect, Environmental Economics and Policy,