SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

LaFrance, Jeffrey T.; Burt, Oscar R..

Aggregate U.S. agricultural supply response is modeled through a modified partial adjustment model, where the effects of weather and other temporal stochastic effects are structured to be purely static, while the effects of price and technology, or trend, are dynamic. The model is applied to a time series of aggregate U.S. farm output, aggregate U.S. crop production, and aggregate U.S. livestock and livestock products production for several sample periods within the period 1911-1958. The three aggregate output indexes are tested for irreversibilities in supply response, and no evidence of a definitive irreversible supply function is found for any of the dynamic supply models. The use of a nonstochastic difference equation to model the aggregate farm...

Tipo: Journal Article

Palavras-chave: Demand and Price Analysis; Production Economics.

Ano: 1983

URL: http://purl.umn.edu/32483

A Simple Lagrange Multiplier F-Test for Multivariate Regression Models

Beatty, Timothy K.M.; LaFrance, Jeffrey T.; Yang, Muzhe.

This paper proposes a straightforward, easy to implement approximate F-test which is useful for testing restrictions in multivariate regression models. We derive the asymptotics for our test statistic and investigate its finite sample properties through a series of Monte Carlo experiments. Both theory suggests and simulations confirm that our approach will result in strictly better inference than the leading alternative

Aggregation Theory for Incomplete Systems

Palavras-chave: Research Methods/ Statistical Methods.

Ano: 2005

URL: http://purl.umn.edu/25074

LaFrance, Jeffrey T.; Beatty, Timothy K.M.; Pope, Rulon D..

Gorman's theory of demand is extended comprehensively to incomplete systems. The incomplete systems approach dramatically increases this class of models. The separate roles of symmetry and adding up are identified in the rank and the functional form of this class of models. We show that symmetry determines rank and the maximum rank is three. We show that adding up and 0o homogeneity determines the functional form and there is no functional form restriction for an incomplete system. We prove that every full rank system and reduced rank systems with a minimal level of degeneracy can be written as a polynomial in a single function of income. A complete set of closed form solutions for the indirect objective functions of this class of models is derived. A...

Agricultural Arbitrage, Adjustment Costs, and the Intensive Margin

Palavras-chave: Aggregation; Rank; Functional form; Integrability; Incomplete systems; Weak integrability; Demand and Price Analysis; D12; E21.

Ano: 2005

URL: http://purl.umn.edu/25033

Tack, Jesse B.; LaFrance, Jeffrey T..

Farmland and capital are an important and rapidly expanding component of the agricultural economy, and empirical evidence suggests that these assets are quasi-fixed in that adjustment costs are incurred when holdings are altered. Increased interest in the rate of return for investing in farmland suggests that an important consideration is the effect of adjustment costs on this return. A novel theoretical model is developed that ties together contributions from the farmland pricing and adjustment cost literatures, and the first order conditions for a utility maximizing decision maker are rearranged into intertemporal arbitrage equations that are similar in spirit to traditional finance models. The common assumptions that land and capital are quasi-fixed...

Tipo: Conference Paper or Presentation

Palavras-chave: Arbitrage; Adjustment Costs; Farmland; Asset Pricing; Capital; Cost Function; Risk; Production; Agricultural Finance; Consumer/Household Economics; Crop Production/Industries; Farm Management; Financial Economics; Land Economics/Use; Production Economics; Risk and Uncertainty.

Ano: 2010

URL: http://purl.umn.edu/56412

Agricultural Arbitrage and Risk Preferences

Pope, Rulon D.; LaFrance, Jeffrey T.; Just, Richard E..

A structural inter-temporal model of agricultural asset arbitrage equilibrium is developed and applied to agriculture in the North-Central region of the U.S. The data is consistent with unifying level of risk aversion. The levels of risk aversion are more plausible than previous estimates for agriculture. However, the standard arbitrage equilibrium is rejected; perhaps this is due to the period and the shortness of the period studied.

AJAE Appendix: Homogeneity and Supply

Palavras-chave: Risk and Uncertainty.

Ano: 2007

URL: http://purl.umn.edu/7189

LaFrance, Jeffrey T.; Pope, Rulon D..

Downloads prior to moving to this URL on 12/08/08: 2008_05 15 2008_06 15 2008_07 11 2008_08 10 2008_09 12 2008_10 7

Tipo: Journal Article

Palavras-chave: Demand and Price Analysis.

Ano: 2008

URL: http://purl.umn.edu/45710

AN ECONOMETRIC MODEL OF THE DEMAND FOR FOOD AND NUTRITION

A flexible, full rank two model of food consumption that is globally consistent with economic theory, aggregates across income, demographic variables, and variations in micro demand parameters, and accommodates tradeoffs between tastes and nutrition is derived. The econometric demand model is estimated with per capita U.S. consumption of 21 foods on the time period 1919-1994, excluding the World War II years 1942-1946. An approach for inferring the percentage of nutrients available from individual commodities in the U.S. food supply is derived and implemented empirically on the time period 1949-1995 for the nutrients energy, protein, total fat, carbohydrates, and cholesterol. The two sets of model results are combined to generate time paths for income...

Palavras-chave: Aggregation; Demand; Food; Nutrition; Hicksian Compensated Price Elasticities; Demand and Price Analysis; Food Consumption/Nutrition/Food Safety.

Ano: 1999

URL: http://purl.umn.edu/25004

Building Gorman's Nest

LaFrance, Jeffrey T.; Beatty, Timothy K.M.; Pope, Rulon D..

Gorman Engel curves are extended to incomplete systems. The roles of Slutsky symmetry and homogeneity/adding up are isolated in the rank and functional form restrictions for Gorman systems. Symmetry determines the rank condition. The maximum rank is three for incomplete and complete systems. Homogeneity/adding up determines the functional form restrictions in complete systems. There is no restriction on functional form in an incomplete system. Every full rank and minimal deficit reduced rank Gorman system has a representation as a polynomial in a single function of income. This generates a complete taxonomy of indirect preferences for Gorman systems. Using this taxonomy, we develop models of incomplete Gorman systems that nest rank and functional form and...

DO INCREASED COMMODITY PRICES LEAD TO MORE OR LESS SOIL DEGRADATION?

Palavras-chave: Aggregation; Functional form; Gorman Engel curves; Incomplete demand systems; Rank; Weak integrability; Demand and Price Analysis; D12; E21.

Ano: 2004

URL: http://purl.umn.edu/25027

DUALITY THEORY FOR THE HOUSEHOLD

In this paper, a dynamic economic model is used to analyze the conflicting impacts of crop increasing/land degrading inputs with those of soil conserving/crop reducing inputs in problems of soil degradation in agriculture. Soil is a renewable resource that is generated naturally at a slow, essentially autonomous rate. Cultivation enhances crop production and degrades the soil, while conservation is unproductive for the crop but improves the soil resource. If the effects of cultivation dominate the effects of conservation in the soil dynamics, an increase in the price of the crop accelerates the rate of soil degradation In the short-run and decreases the long-run stock of the soil resource. On the other hand, if the effects of conservation dominate the...

Tipo: Journal Article

Palavras-chave: Land Economics/Use.

Ano: 1992

URL: http://purl.umn.edu/22478

Energy efficiency and appliance replacement

Palavras-chave: Consumer/Household Economics.

Ano: 2000

URL: http://purl.umn.edu/25058

Full Rank Rational Demand Systems

Engineering models generally find that most consumers are unwilling to adopt energy efficient appliances, even though the financial returns are positive. It is commonly thought that this is either due to market imperfections such as an incomplete credit market, very high intertemporal consumer discount rates, or irrational behavior. This paper presents a more sanguine explanation based on a model of rational dynamic choice in an uncertain environment. A random utility model (RUM) with consumer preferences that depend on the quality mix of energy-using appliances predicts that under plausible conditions - including the consumer's intertemporal discount rate equal to the real market rate of return on risk free investments - it may well be optimal for...

Tipo: Working Paper

Palavras-chave: Appliances; Consumers' preferences; Econometric models; Efficiency; Energy; Consumer/Household Economics.

Ano: 2005

URL: http://purl.umn.edu/120462

LaFrance, Jeffrey T.; Pope, Rulon D..

We extend the set of full rank nominal and deflated income demand systems to rational demand systems of any rank and present a unifying expression for the indirect preferences of all full rank demand models.

Generalized Rational Random Errors

Palavras-chave: Aggregation; Functional form; Integrability; Rank; Rational demand systems; Demand and Price Analysis; D12; E21.

Ano: 2006

URL: http://purl.umn.edu/7152

Theil's theory of rational random errors is sufficient for strict exogeneity of group expenditure in separable demand models. Generalized rational random errors is necessary and sufficient for strict exogeneity of group expenditure. A simple, robust, asymptotically normal t-test of this hypothesis is derived based on the generalized method of moments. An application to per capita annual U.S. food demand in the 20th century strongly rejects exogeneity of food expenditure in a model that in all other respects is highly compatible with the data set and with the implications of economic theory.

Grazing Fees versus Stewardship on Federal Lands

Palavras-chave: Demand; Generalized method of moments; Rational random errors; Weak separability; Demand and Price Analysis.

Ano: 2002

URL: http://purl.umn.edu/25053

Watts, Myles J.; Shimshack, Jay P.; LaFrance, Jeffrey T..

Livestock grazing on public lands continues to be a source of intense conflict and debate. We analyze this problem using a dynamic game. Low grazing fees let ranchers capture more rent from grazing. This increases the incentive to comply with federally mandated regulations. Optimal grazing contracts therefore include grazing fees that are lower than competitive private rates. The optimal policy also includes random monitoring to prevent strategic learning by cheating ranchers and avoid wasteful efforts to disguise noncompliant behavior. Finally, an optimal policy includes a penalty for cheating beyond terminating the lease. This penalty must be large enough that the rancher who would profit the most from cheating experiences a negative expected net return.

GUIDELINES FOR WESTERN JOURNAL OF AGRICULTURAL ECONOMICS AUTHORS

Palavras-chave: Renewable resources; Public lands grazing policy; Optimal contracts; Land Economics/Use.

Ano: 2006

URL: http://purl.umn.edu/7151

LaFrance, Jeffrey T.; Watts, Myles J..

This article explains the current editorial procedures and policies of the Western Journal of Agricultural Economics. The contents should be of interest both to readers and to authors who plan to submit manuscripts to the Journal. The current editorial policy of the Journal is discussed, the review and publication process is explained, and detailed guidelines for the proper preparation of manuscripts for the Journal are presented.

Tipo: Journal Article

Palavras-chave: Teaching/Communication/Extension/Profession.

Ano: 1991

URL: http://purl.umn.edu/32598

HOMOGENEITY AND SUPPLY

LaFrance, Jeffrey T.; Pope, Rulon D..

Supply functions in the ubiquitous Gorman class are examined for their homogeneity properties. Homogeneity places surprisingly strong restrictions on functional forms. These forms facilitate testing of aggregability given homogeneity or homogeneity given aggregability or testing both.

INCOME ELASTICITY AND FUNCTIONAL FORM

Palavras-chave: Research Methods/ Statistical Methods.

Ano: 2007

URL: http://purl.umn.edu/6863

Beatty, Timothy K.M.; LaFrance, Jeffrey T..

INCOMPLETE DEMAND SYSTEMS AND SEMILOGARITHMIC DEMAND MODELS

Palavras-chave: Demand and Price Analysis.

Ano: 2004

URL: http://purl.umn.edu/15835

INFERRING THE NUTRIENT CONTENT OF FOOD WITH PRIOR INFORMATION

The methodology of LaFrance and Hanemann for analysing the structure of incomplete demand systems is applied to models that are linear or logarithmic in quantities, prices and/or income. The structure of each model is presented when the implications of consumer choice theory are satisfied. The usefulness of the approach is illustrated. It is shown that considerable prior information is obtained from the theory of consumer choice when it is applied to this set of functional forms for demand equations.

Tipo: Journal Article

Palavras-chave: Demand and Price Analysis.

Ano: 1990

URL: http://purl.umn.edu/22442

Given measurements on the nutrient content of the U.S. food supply and a coherent reduced form empirical model of the demand for foods, we can analyze the effect of agricultural farm and food policy on nutrition. Using unpublished documents from the HNIS, estimates of the percentages of seventeen nutrients supplied by twenty-one foods were compiled for the period 1952-1983. The Bayesian Method of Moments is applied to this data set to obtain a proper prior for the purpose of drawing year-to-year inferences about the nutrient content of the U.S. food supply for the period 1909-1994. Information theory and the Kullback-Leibler cross entropy criterion are used to formalize the inference problem.

Milk Marketing Order Winners and Losers

Palavras-chave: Agricultural Farm and Food Policy; Bayesian Method of Moments; Generalized Maximum Entropy; Kullback-Leibler Cross Entropy; Nutrient Content; Food Consumption/Nutrition/Food Safety.

Ano: 1998

URL: http://purl.umn.edu/25067