2,158 research outputs found
Is Self-Sufficiency for Womens Collegiate Athletics a Hoop Dream?: Willingness to Pay for Mens and Womens Basketball Tickets
Universities spend almost $2 billion subsidizing their collegiate sports programs.� Even the most popular women’s sport, basketball, fails to break even. An application of Becker’s theory of customer discrimination is used to calculate the relative preference for men’s basketball for both men and women. Median willingness to pay for men’s basketball relative to women’s basketball is 180% greater for men and 37% greater for women.� Pricing each sport at its revenue maximizing price, revenues from women’s basketball are only 43% of that for men, even at a school with historically strong demand for women’s sports.Basketball; Becker; reservation price; revenue; customer discrimination; cross marketing; NCAA
Does Duality Theory Hold in Practice? A Monte Carlo Analysis for U.S. Agriculture
The Neoclassical theory of production establishes a dual relationship between the profit value function of a competitive firm and its underlying production technology. This relationship, usually referred to as the duality theory, has been widely used in empirical work to estimate production parameters without the requirement of explicitly specifying the technology. We analyze the ability of this approach to recover the underlying production parameters and its effects on estimated elasticities and scale economies measurements, when data available for estimation features typical realistic problems. We design alternative scenarios and compute the data generating process by Monte Carlo simulations, so as to know the true technology parameters as well as to calibrate the dataset to yield realistic magnitudes of noise. This noise introduced in the estimation by construction prevents duality theory from holding exactly. Hence, the true production parameters may not be recovered with enough precision, and the estimated elasticities or scale economies measurements may be more inaccurate than expected. We compare the estimated production parameters with the true (and known) parameters by means of the identities between the Hessians of the production and profit functions.duality theory, firm’s heterogeneity, measurement error, data aggregation, omitted variables, endogeneity, uncertainty, Monte Carlo simulations., Crop Production/Industries, Production Economics, Risk and Uncertainty, Q12, D22, D81,
Yield and Area Elasticities. A Cost Function Approach with Uncertainty
This paper develops a method to jointly estimate crop yield elasticities and area elasticities with respect to output prices based on a theoretically consistent model. The model uses a duality theory approach for the multi-output and multi-input firm, and introduces uncertainty in the level of target output which conditions the cost minimization problem, in the output prices and in the conditional input demand functions. The underlying production technology is conditioned on fixed inputs, both allocatable and non-allocatable. Up to our knowledge, there have been no theoretical developments of this type of models for multioutput technologies. Our approach is also novel because no previous model of this type has introduced the effects of allocatable fixed inputs. We provide an empirical application of this theoretical framework using State-level data and approximating the dual cost function by a normalized quadratic flexible functional form. We derive expressions for the elasticities of interest conditional on the function specification assumed.yield elasticities, area elasticities, duality theory, cost function, uncertainty, Production Economics,
Relaciones intergubernamentales y gobernanza metropolitana: hacia una perspectiva integral
La dinámica de crecimiento experimentada en las Ăşltimas dos dĂ©cadas en el mundo deja claro que, hoy por hoy, la constante y acelerada urbanizaciĂłn exige nuevas fĂłrmulas de planeaciĂłn y administraciĂłn de las ciudades, sobre todo en aquellos territorios en los que la tendencia indica que seguirán siendo atractivos para el desarrollo empresarial, inmobiliario, comercial, cultural y social, factores que a su vez influyen en la creaciĂłn de nuevos desarrollos habitacionales, cuya poblaciĂłn reclama respuestas eficaces de sus autoridades locales. El fenĂłmeno de la metropolizaciĂłn no es nuevo en el orden mundial. Desde principios del siglo xx se ha manifestado con mayor intensidad en diversos continentes y regiones. El Instituto Mexicano para la Competitividad, a.c. (2010), destaca que por primera vez en la historia del planeta el nĂşmero de personas que vive en las ciudades es equivalente al nĂşmero de habitantes en zonas rurales. Naciones como China e India se perfilan como paĂses eminentemente urbanos. Esta tendencia es irreversible. Para el año 2050 se espera que el 75% de la poblaciĂłn global viva en una ciudad. Hoy siete de cada diez mexicanos reside en poblaciones con más de 15 mil habitantes.Con el propĂłsito de profundizar en las formas de coordinaciĂłn entre los diversos niveles de gobierno, en este artĂculo se incluye una breve reseña de las relaciones intergubernamentales (rig’s) como parte de los estudios de la AdministraciĂłn PĂşblica, abordando su origen, conceptualizaciĂłn, enfoques, relaciones con el federalismo, evoluciĂłn en el caso mexicano, su complejidad ante la consideraciĂłn obligada de una multiplicidad de actores con fines heterogĂ©neos y los elementos para su estudio, asĂ como el nexo con la descentralizaciĂłn y la gobernanza metropolitana, precisando sus interrelaciones para arribar a un esquema integral, cuyo desarrollo oriente la planeaciĂłn de los territorios que enfrentan complejos procesos de urbanizaciĂłn y demandan respuestas gubernamentales eficaces.Universidad AutĂłnoma del Estado de MĂ©xic
World Fertilizer Model—The WorldNPK Model
We introduce a world fertilizers model that is capable of producing fertilizer demand projections by crop, by country, by macronutrients, and by year. For each crop, the most relevant countries in terms of production, consumption, or trade are explicitly modeled. The remaining countries are modeled, for each crop, within a regional aggregate. The nutrient coverage includes nitrogen (N), phosphorous (P), and potassium (K). In this report we present the data and procedures used to set up the model as well as the assumptions made. The fertilizer model interacts with the yield equations of the FAPRI-ISU model (Food and Agricultural Policy Research Institute at Iowa State University), and by means of a set of production elasticities, projects each nutrient’s application rate per hectare for each commodity and each country covered by the FAPRI-ISU model. Then, the application rates and the areas projected by FAPRIISU are used to obtain projections of fertilizer demand from agriculture on a global scale. With this fertilizer module, policies that directly affect fertilizer markets, such as input taxes or subsidies, quantity use restrictions, and trade restrictions, can now be explicitly formulated and evaluated. The effects of these policies on global agricultural markets and on greenhouse gas emissions can be evaluated with the FAPRI-ISU model and the Greenhouse Gas in Agriculture Simulation Model (GreenAgSiM). Also, any other policy affecting commodity markets such as input and output price shocks, biofuels mandates, and land-use change can now be evaluated with regard to its impacts on the world fertilizer markets
Fertilizer Use by Crop at the Country Level (1990–2010)
We compute the fertilizer use in corn, cotton, soybeans, and rapeseed in the period from 1990 to 2010 for a set of selected countries. In each case, we present the consumption of nitrogen, phosphate, and potash by crop and by year, reporting both the fertilizer application rates (in kilograms per hectare) and the fertilizer consumption (in thousand metric tonnes). We allocate a country’s total nutrient consumption in a given year among competing crops based on publicly available statistics. The resulting allocation of fertilizer among crops is a function of the country’s nutrients total use, the country’s cropped areas, crop world prices, and crop- and country-specific fertilizer application rates for some years. In this report we show results on fertilizer consumption by crop for the top fertilizer consuming countries, and a downloadable MS Excel file “FertilizerDemandByCropData.xls” shows the complete set of results
High temperature treatments of porous activated carbon
The use of biomass waste for the preparation of activated carbon is of great industrial interest for reducing costs and increasing the sustainability, especially in the field of energy storage. A high temperature treatment is required to obtain a more ordered carbon material, thus increasing its conductivity. However, this high temperature treatment entails as a disadvantage a significant reduction in porosity. Therefore, a method to prepare activated carbons with a high porosity development as well as high conductivity could be of great interest for many applications.
The aim of this work is to analyze the possible influence of phosphorus compounds on the physical-chemical properties of different carbon materials thermally treated at relatively high temperatures (1600 ÂşC). With this goal, it has been prepared activated carbons from different precursors (olive stone, lignin and hemp) and different conformations (powder, fibers and monoliths) by physical and chemical activation, with CO2 and H3PO4, respectively.
Once the different activated carbon materials were prepared, they were thermally treated at 1600 ÂşC under inert atmosphere. The different samples were characterized by N2 and CO2 adsorption at 77 and 273 K, respectively, XPS, XRD and Raman techniques. The oxidation resistance was also evaluated in a thermogravimetric balance. High temperature treatments of activated carbon without the presence of P surface groups produced an important contraction of the porosity (from 900 to 150 m2 g-1). However, temperature treatments of phosphorus-activated carbon allowed for preparing carbon materials with a relatively high structural order and a well-developed porosity (c.a. 1100 m2 g-1), with a significant contribution of mesoporosity. These results suggest that these P-surface groups are responsible for the low contraction observed for the porous structure, avoiding, in a large extent, its collapse.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech.
MINECO (CTQ2015-68654-R).
MINECO (PTA2015-11464-I)
Essays on the environmental effects of agricultural production
This dissertation is devoted to the study of environmental effects of agricultural production. Recent periods of high demand for agricultural products and the increase of world commodity prices result, in part, from the implementation of biofuel policies and the growth of per-capita income in developing countries. The extent to which food, feed, and fuel demands are satisfied depends on the ability of agricultural supply to react to these events. In economics, supply response models are used as the framework to analyze these types of problems in providing estimated magnitudes of the mentioned effects. The accuracy with which these magnitudes are calculated impacts the measurement of environmental effects of agricultural production, such as green-house gas emissions and land use change at a global scale, having important consequences on country-level accountings. Chapter 2 analyzes the econometric applications of the Neoclassical duality theory of the firm intended to measure the response of production quantities to price changes. We find that the use of real-world market-based data, which is typically available to practitioners but includes features that contradict some hypothesis of the theory, induces bias in the estimated supply response values. In light of these results, Chapter 3 proposes an alternative approach that overcomes the problems encountered when duality theory is applied to real-world data. This novel approach combines market-based data with information about production functions, which are simultaneously used in the econometric estimation of the supply response parameters. The methodology employs Bayesian econometric methods and bases the complementarity among the various datasets on underlined theoretical relationships. An application of this approach to U.S. agriculture provides updated measures of crop yield elasticities with respect to prices. Chapter 4 takes on the issue of direct environmental effects from agricultural production. In particular, it documents and quantifies the effects on nitrous oxide emissions from cutting nitrogen fertilizer applications when farmers face a market instrument intended to discourage the excessive use of nitrogen in soils. An expected utility maximization problem is specified where the farmer chooses the optimal nitrogen application facing a nonlinear market instrument. The nonlinearity captures the nonlinear relationship between nitrogen applications and nitrous oxide emissions and is arguably more efficient than linear schemes. Simulation results for U.S. corn show that farmers are induced to significantly reduce their fertilization (and consequently emissions) with only minor effects on expected crop yields
Modification of the morphology, porosity and surface chemistry of lignin-based electrospun carbon materials
Lignin is a biopolymer that can be found as the main component of plants. It is obtained as a coproduct in the papermaking and biofuel industries. Owing to its high carbon and aromatic content, high availability and reduced cost, it is an excellent precursor for the preparation of highly valued carbon materials. Electrospinning is a suitable top-down technique for the preparation of polymeric fibers using high voltage electrical fields and polymer solutions of proper viscosity and conductivity. Organosolv lignins, which are extracted from lignocellulosic biomass using organic solvents, are soluble in ethanol, obtaining a solution that matches the requirement of the electrospinning process. In this way, it is possible to produce lignin-based porous carbon fibers using a coaxial electrospinning device [1]. This contribution summarizes our findings about the preparation of carbon materials with different morphologies and composition by processing lignin using electrohydrodynamic forces. Lignin spheres, beaded fibers, straight fibers, beaded tubes and straight tubes are obtained by using coaxial and triaxial spinnerets that allows the electrospinning of two or three different solutions at once [1], Fig. 1. Thermal stabilization in air is needed in order to avoid melting of lignin fibers during carbonization. Stabilization times of 48-96 hours are usually required in this step, decreasing the sustainability of the production process. Phosphoric acid can be added in small amounts in the lignin solution, shortening the time for achieve a successful thermostabilization of the fiber [2]. The carbonized materials show narrow microporosity and large surface area values (SBET from 600 to 1000 m2g-1) and additional pore size and volume can be developed by controlled gasification.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech.
This work was supported by the Spanish Ministry of Economy and Competitiveness and FEDER (CTQ-2015-68654-R)
A Nonlinear Offset Program to Reduce Nitrous Oxide Emissions Induced by Excessive Nitrogen Application
On average, U.S. farmers choose to apply nitrogen fertilizer at a rate that exceeds the ex post agronomically optimal rate. The technology underlying the yield response to nitrogen rewards producers who over apply in years when rainfall is excessive. The overapplication of nutrients has negative environmental consequences because the nitrogen that is not taken up by the plant will typically volatilize causing N2O emissions, or leach causing water pollution. We present a nonlinear offset program that induces farmers to reduce their nitrogen applications to the level that will be consumed by the plant in a typical year and, as a result, reduce N2O emissions from agriculture. The offset program is nonlinear because of the nonlinear relationship between N2O and nitrogen application rates. We assume that the farmer solves an expected utility maximization problem, choosing the optimal nitrogen application rate. The key contribution is a set of simulations that shows that modest offset payments will induce participation in the program and will have a significant impact on both expected and actual N2O emissions without having a significant impact on actual or expected yields. We also find that more risk-averse farmers will reduce emissions by a greater amount than less risk-averse farmers. Finally, we show the distribution of emission reductions induced by this nonlinear offset scheme.nitrogen fertilizer; carbon offsets; nitrous oxide; pollution; uncertainty.
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