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Registros recuperados: 17
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A BAYESIAN FRAMEWORK FOR OPTIMAL INPUT ALLOCATION WITH AN UNCERTAIN STOCHASTIC PRODUCTION FUNCTION 31
Griffiths, William E..
A Bayesian approach is used to provide a framework for optimal input allocation for a stochastic production function with uncertain parameters. The chosen production function is a single-input version of a function which can exhibit positive or negative marginal risk. The sensitivity of optimal input allocation to the degree of risk aversion, the marginal risk parameter, and the assumed level of uncertainty about the parameters is examined. Using an example problem it is shown that parameter uncertainty will not always lead to a lower input level when a producer is risk averse. Some problems with the production function specification are uncovered, as is the incompatibility of some expected utility and stochastic assumptions.
Tipo: Journal Article Palavras-chave: Research Methods/ Statistical Methods; Risk and Uncertainty.
Ano: 1986 URL: http://purl.umn.edu/22898
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A UNIFIED APPROACH TO SENSITIVITY ANALYSIS IN EQUILIBRIUM DISPLACEMENT MODELS: COMMENT 31
Griffiths, William E.; Zhao, Xueyan.
It is pointed out that the Chebychev confidence intervals and maximum p-values advocated by Davis and Espinoza for sensitivity analysis of equilibrium displacement models are unnecessary. Desired probability intervals and probabilities can be accurately estimated without resorting to gross approximations.
Tipo: Working or Discussion Paper Palavras-chave: Simulation; Probability distributions; Empirical quantiles; Research Methods/ Statistical Methods.
Ano: 1999 URL: http://purl.umn.edu/12950
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An Equilibrium Displacement Model of the Australian Beef Industry 31
Zhao, Xueyan; Mullen, John D.; Griffith, Garry R.; Griffiths, William E.; Piggott, Roley R..
Around $100 million has been spent annually on R&D and promotion in the Australian red meat industries in recent years. The R&D investments are made throughout the production, processing and marketing chain in both the grass and grain finished sectors. Promotion investments are made in both export and domestic markets. Despite this large investment of industry and government funds there is great uncertainty about the returns from these investments. Not only is it unclear what the total industry returns are but it is even less clear how producers and the community benefit from the many alternative investment options. Hence, it is unclear how funds should be allocated between these alternatives. Zhao (1999) addressed these issues in research for...
Tipo: Report Palavras-chave: Industrial Organization; Research and Development/Tech Change/Emerging Technologies.
Ano: 2000 URL: http://purl.umn.edu/28007
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Bayesian Econometrics and How to Get Rid of Those Wrong Signs 31
Griffiths, William E..
In many instances, Bayesian Econometrics offers a more natural interpretation of the results of a statistical investigation than does the sampling theory approach. Furthermore, the Bayesian approach provides a formal framework for incorporating prior information which is frequently available from economic theory. Despite these advantages of the Bayesian approach, applied econometric work has generally been dominated by the sampling theory approach. A simple regression example with one coefficient is used to describe the Bayesian approach using three different priors: a natural conjugate informative prior, a non informative prior, and a prior with inequality restrictions on the sign and possibly magnitude of the coefficient. The differences between the...
Tipo: Journal Article Palavras-chave: Research Methods/ Statistical Methods.
Ano: 1988 URL: http://purl.umn.edu/9662
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Carnarvon Gorge: a comment on the sensitivity of consumer surplus estimation 31
Chotikapanich, Duangkamon; Griffiths, William E..
Beal’s (1995) method of estimating the value of Carnarvon Gorge for recreational use is re‐examined. When an inconsistency in her estimation procedure is corrected, the estimated value of Carnarvon Gorge for camping is found to be six times higher. The sensitivity of the estimate to the choice of functional form is examined, and standard errors and interval estimates for consumer surplus are provided. Comments are made about functional form choice and prediction in log‐log models.
Tipo: Journal Article Palavras-chave: Resource /Energy Economics and Policy.
Ano: 1998 URL: http://purl.umn.edu/117233
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ESTIMATION OF ACTUAL RESPONSE COEFFICIENTS IN THE HILDRETH-HOUCK RANDOM COEFFICIENT MODEL 31
Griffiths, William E..
Tipo: Working or Discussion Paper Palavras-chave: Research Methods/ Statistical Methods.
Ano: 1971 URL: http://purl.umn.edu/14275
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FLEXIBLE DISTRIBUTED LAGS 31
Chotikapanich, Duangkamon; Griffiths, William E..
In econometrics there is a long history of using continuous functions to force distributed lag coefficients to behave in an economically accepted way. For example, geometrically declining lags have often been used to model coefficients that we believe should be declining. Polynomial lags have been used to model lag coefficients expected to increase and then decrease. In this paper a more flexible way of imposing such prior information is investigated. Inequality constraints are used to impose knowledge about the relative magnitudes of coefficients without forcing them to lie on a smooth continuous curve. A Metropolis algorithm is used to get posterior density functions for the lag coefficients and functions of those coefficients for the Nerlove orange data...
Tipo: Presentation Palavras-chave: Research Methods/ Statistical Methods.
Ano: 2000 URL: http://purl.umn.edu/123623
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GENERALIZED LEAST SQUARES WITH AN ESTIMATED COVARIANCE MATRIX -- A SAMPLING EXPERIMENT 31
Griffiths, William E..
Tipo: Working or Discussion Paper Palavras-chave: Research Methods/ Statistical Methods.
Ano: 1971 URL: http://purl.umn.edu/13370
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Imposing regularity conditions on a system of cost and factor share equations 31
Griffiths, William E.; O'Donnell, Christopher J.; Cruz, Agustina Tan.
Systems of equations comprising cost functions and first‐order derivative equations are often used to estimate characteristics of production technologies. Unfortunately, many estimated systems violate the regularity conditions implied by economic theory. Sampling theory methods can be used to impose these conditions globally, but these methods destroy the flexibility properties of most functional forms. We demonstrate how Bayesian methods can be used to maintain flexibility by imposing regularity conditions locally. The Bayesian approach is used to estimate a system of cost and share equations for the merino wool‐growing sector. The effect of local imposition of monotonicity and concavity on the signs and magnitudes of elasticities is examined.
Tipo: Journal Article Palavras-chave: Resource /Energy Economics and Policy.
Ano: 2000 URL: http://purl.umn.edu/117790
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IMPOSING REGULARITY CONDITIONS ON A SYSTEM OF COST AND FACTOR SHARE EQUATIONS 31
Griffiths, William E.; O'Donnell, Christopher J.; Cruz, Agustina Tan.
Systems of equations comprising cost functions and first-order derivative equations are often used to estimate characteristics of production technologies. Unfortunately, many estimated systems violate the regularity conditions implied by economic theory. Sampling theory methods can be used to impose these conditions globally, but these methods destroy the flexibility properties of most functional forms. We demonstrate how Bayesian methods can be used to maintain flexibility by imposing regularity conditions locally. The Bayesian approach is used to estimate a system of cost and share equations for the merino-woolgrowing sector. The effect of local imposition of monotonicity and concavity on the signs and magnitudes of elasticities is examined.
Tipo: Working or Discussion Paper Palavras-chave: Cost functions; Markov Chain Monte Carlo; Inequality constraints; Demand and Price Analysis.
Ano: 1999 URL: http://purl.umn.edu/12925
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MULTICOLLINEARITY IN REGRESSION WITH QUADRATIC REGRESSORS 31
Griffiths, William E..
Tipo: Working or Discussion Paper Palavras-chave: Research Methods/ Statistical Methods.
Ano: 1971 URL: http://purl.umn.edu/13441
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PREDICTING OUTPUT FROM SEEMINGLY UNRELATED AREA AND YIELD EQUATIONS 31
Griffiths, William E.; Thomson, Graeme; Coelli, Tim J..
Crop output can be defined as the product of area sown and yield. Given the existence of separate equations for explaining and predicting area sown and yield, in this paper we suggest predictors for output and derive expressions for the standard errors of the predictors. The methodology is applied to wheat production in the Corrigin Shire of Western Australia.
Tipo: Working or Discussion Paper Palavras-chave: Predicting a product; Standard error of prediction; Crop Production/Industries.
Ano: 1999 URL: http://purl.umn.edu/12945
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Probability distributions for economic surplus changes: the case of technical change in the Australian wool industry 31
Zhao, Xueyan; Griffiths, William E.; Griffith, Garry R.; Mullen, John D..
Mullen, Alston and Wohlgenant (1989) (MAW) examined the distribution of the benefits of technical change in the Australian wool industry. Their conclusions are revisited by examining the probability distributions of changes in the welfare measures, given uncertainty about their model parameters. Subjective probability distributions are specified for the parameters and correlations among some of the parameters are imposed. Hierarchical distributions are also used to model diverse views about the specification of the subjective distributions. A sensitivity elasticity is defined through the estimation of a response surface to measure the sensitivity of the estimated research benefits to individual parameters. MAW’s conclusions are found to be robust under the...
Tipo: Journal Article Palavras-chave: Livestock Production/Industries.
Ano: 2000 URL: http://purl.umn.edu/117789
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PRODUCTION RISK AND EFFICIENT ALLOCATION OF RESOURCES 31
Anderson, Jock R.; Griffiths, William E..
Efficient allocation of resources has usually been couched in risk less terms, partly because statistical techniques did not exist for measuring the impact of varying levels of factors of production on risks associated with production. Now that such techniques are available, methods are required for determining efficient allocations. Such models, particularly those exploiting stochastic efficiency analysis, are illustrated here with respect to empirical risk-sensitive, farm-firm production functions.
Tipo: Journal Article Palavras-chave: Risk and Uncertainty.
Ano: 1982 URL: http://purl.umn.edu/22706
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PRODUCTION RISK AND INPUT USE: PASTORAL ZONE OF EASTERN AUSTRALIA 31
Anderson, Jock R.; Griffiths, William E..
Few attempts have been made to estimate production functions for the Australian grazing industries. The question of the nature of the effect of input levels on production risk has been broached even more rarely. Previous investigators had to employ models and methods of estimation which embody highly restrictive implicit assumptions about the nature of risk effects. A typical restrictive feature has been the implication that increasing input intensity leads to increasing risk. In this paper, a much less restrictive model and corresponding estimation techniques are brought to bear on individual farm data for 38 properties with 10 continuous years of production records. Perhaps not surprisingly, it is found that some inputs (especially those capital inputs...
Tipo: Journal Article Palavras-chave: Productivity Analysis; Risk and Uncertainty.
Ano: 1981 URL: http://purl.umn.edu/22867
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SPECIFICATION OF AGRICULTURAL SUPPLY FUNCTIONS - EMPIRICAL EVIDENCE ON WHEAT IN SOUTHERN N.S.W 31
Griffiths, William E.; Anderson, Jock R..
The implications of alternative disturbance specifications in supply functions have been considered in recent theoretical work but little, if any, empirical evidence has been provided on such specifications. Any empirical investigation of the nature of a supply function disturbance is hampered by considerable uncertainty about the deterministic part of the function. Nevertheless, some progress might be made by considering alternative disturbance specifications in conjunction with a variety of deterministic specifications. Applying this approach to the supply of wheat in southern N.S.W., we find some empirical support for an additive disturbance and, surprisingly, for the use of price, rather than revenue, as an argument In supply functions.
Tipo: Journal Article Palavras-chave: Crop Production/Industries.
Ano: 1978 URL: http://purl.umn.edu/22712
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SUBJECTIVE DISTRIBUTIONS AS ECONOMETRIC RESPONSE DATA 31
Griffiths, William E.; Anderson, Jock R.; Hamal, K.B..
Analysis of actual observations of response processes is a routine procedure in applied econometrics but methods of dealing with purely subjective probability distributions as response 'data' have seemingly not hitherto been worked out. The models and methods developed here go some way to filling this void. They are illustrated by using information from a cross-sectional study of sixty Nepalese small-scale farmers. Means and variances of subjective probability distributions for rice paddy yields under different technologies are related to controlled inputs, such as fertiliser levels, and to relevant socio-economic aspects of farmers themselves, such as technological knowledge and farm size.
Tipo: Journal Article Palavras-chave: Research Methods/ Statistical Methods.
Ano: 1987 URL: http://purl.umn.edu/22451
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