15,546 research outputs found

    Long-term Global Agricultural Output Supply-Demand Balance and Real Farm and Food Prices

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    Global food demand is estimated from population projections of the United Nations and food supply is projected from Food and Agriculture Organization yield data to quantify the global food supply-demand balance for 2025 and 2050. The eight food categories examined account for 95 percent of global food consumption. Results indicate that the historic era of secularly falling real food prices is over. The real price of corn, for example, is not expected to fall over the next four decades at the annual rate of 1.3 percent that it fell annually from 1960 to 2006. The analysis foresees future real food prices fluctuating around a flat or rising trend. Slowed national economic growth from flat or rising real food prices may be little more than an irritant for consumers in affluent countries, but will entail severe hardship for consumers in the many countries currently troubled by poverty and hunger. Opportunities exist to expand food output by adding cropland in Brazil and irrigation in Africa, for example, but in the long term such developments will be offset by cropland removed from production by urban and industrial development, soil degradation, and the like. Although cropland can be expanded through higher real farm and food prices, higher yields rather than added cropland offer the most attractive opportunities for farm output expansion at low cost to consumers and the environment. The slowing rate of increase in crop and livestock yields corresponds with a slowing rate of increase in public and in private agricultural research and development spending. The world will not have the luxury of curtailing spending on agricultural technology and rejecting promising technologies such as genetically modified organisms (GMOs) if is to keep real food costs from rising. Productive new cropland, irrigation, genetically modified varieties, and other technologies will be hard pressed indeed to match the massive historic gains from hybrid varieties, irrigation, synthetic fertilizers, and mechanization. On the demand side, subsidies to expand demand for farming resources such as biofuels will need revisiting if rising food costs are to be contained.World Food Supply-Demand, Food Prices, Agricultural Markets, Crop and Livestock Yields, Agricultural and Food Policy, Demand and Price Analysis, International Development, Q11, Q18,

    Country of Origin Advertising and U.S. Wine Imports

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    The objective of this paper is to investigate the impact of media advertising on the US consumption of imported wine. A panel data of seven countries and twelve years from 1994-2005 is used to estimate the demand function for US wine imports. Our empirical analysis reveals evidence of strong price and advertising effects of domestic and imported wines on imported quantities; the advertising of imported wines significantly increases the quantity of imports while the advertising of domestic wines has a strong depressing effect on imported wine volumes. Our short-run import demand price and advertising elasticity estimates are -0.406 and 0.109 for imports and 0.654 and -0.370 for domestic wines, respectively. Other determinants such as population, real income and country specific fixed effects are also found significant. Based on our model estimates, we compute the marginal return to advertising to be 2.68onaverageforthesiximportingcountriesand2.68 on average for the six importing countries and 3.40 for the U.S.International Relations/Trade, Marketing,

    The MMI cash-futures spread on October 19, 1987

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    Includes bibliographical references (p. 29)

    Three osculating walkers

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    We consider three directed walkers on the square lattice, which move simultaneously at each tick of a clock and never cross. Their trajectories form a non-crossing configuration of walks. This configuration is said to be osculating if the walkers never share an edge, and vicious (or: non-intersecting) if they never meet. We give a closed form expression for the generating function of osculating configurations starting from prescribed points. This generating function turns out to be algebraic. We also relate the enumeration of osculating configurations with prescribed starting and ending points to the (better understood) enumeration of non-intersecting configurations. Our method is based on a step by step decomposition of osculating configurations, and on the solution of the functional equation provided by this decomposition

    A map on the space of rational functions

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    We describe dynamical properties of a map F\mathfrak{F} defined on the space of rational functions. The fixed points of F\mathfrak{F} are classified and the long time behavior of a subclass is described in terms of Eulerian polynomials

    Some Combinatorial Properties of Hook Lengths, Contents, and Parts of Partitions

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    This paper proves a generalization of a conjecture of Guoniu Han, inspired originally by an identity of Nekrasov and Okounkov. The main result states that certain sums over partitions p of n, involving symmetric functions of the squares of the hook lengths of p, are polynomial functions of n. A similar result is obtained for symmetric functions of the contents and shifted parts of n.Comment: 20 pages. Correction of some inaccuracies, and a new Theorem 4.

    Rehybridization of electronic structure in compressed two-dimensional quantum dot superlattices

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    Two-dimensional superlattices of organically passivated 2.6-nm silver quantum dots were prepared as Langmuir monolayers and transferred to highly oriented pyrolytic graphite substrates. The structural and electronic properties of the films were probed with variable temperature scanning tunneling microscopy. Particles passivated with decanethiol (interparticle separation distance of ∼1.1±0.2 nm) exhibited Coulomb blockade and staircase. For particles passivated with hexanethiol or pentanethiol (interparticle separation distance of ∼0.5±0.2 nm), the single-electron charging was quenched, and the redistribution of the density of states revealed that strong quantum mechanical exchange, i.e., wave-function hybridization, existed among the particles in these films

    Cold climate water/wastewater transportation and treatment - a bibliography: completion report

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    This bibliography contains 1,400 citations, including published and unpublished papers, on cold-climate water and wastewater transportation and treatment systems. Sources listed include state and federal agency files which contain information on systems in Alaskan communities and the Alyeska Pipeline Service Company camps. References to systems in other northern countries are also included. The objectives of this study were to identify causes of the failure of Alaskan water and wastewater treatment and transportation facilities and to seek methods for design improvements. Originally, the investigators contemplated an evaluation of systems performance in remote areas in relation to the original conception, planning, design, and construction. Because of the tremendous amount of literature examined, the evaluation was undertaken in a subsequent study, "Alaska Wastewater Treatment Technology" (A-058-ALAS) by Dr. Ronald A. Johnson.OWRT AGREEMENT NO. 14-31-0001-5002 PROJECT NO. A-047-ALAS The work upon which this completion report is based was supported by funds provided by the U. S. Department of the Interior, Office of Water Research and Technology, as authorized under the Water Resources Research Act of 1964, Public Law 88-379, as amended
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