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Time Varying Parameters with Random Components: The Orange Juice Industry

Published online by Cambridge University Press:  28 April 2015

Ronald W. Ward
Affiliation:
Food and Resource Economics Department, University of Florida

Extract

The assumption of nonstochastic parameters has long been recognized as restrictive to the solution of many marketing problems and to economic modeling in general. Parameter variation historically has been treated with the use of nonstochastic adjustments through interaction variables and the use of proxy dummy and trend variables. Though these empirical techniques in many cases give reasonable results, they presuppose that the researcher can specify the nature of the parameter change. In fact, it may not be obvious that random parameters are part of the estimation problem. Furthermore, specification of structural shifts in parameters is usually difficult. Comparison of parameter changes through techniques such as grouping of data and using various F-tests is most often dependent on the criteria for grouping (Maddala, p. 390–404). Also, the procedure fails to identify the dynamic path of adjustments that must have occurred when various F-tests indicate that parameters have changed. Other approaches to determining structural shifts in parameters may require elaborate search procedures. To limit the extent to which the search is required, restrictive assumptions about many of the parameters are sometimes made (Simon).

Type
Research Article
Copyright
Copyright © Southern Agricultural Economics Association 1980

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References

Belsley, David.On the Determination of Systematic Parameter Variation in the Linear Regression Model.Ann. Econ. andSoc. Meas. 2(Oct. 1973):495500.Google Scholar
Cooley, T. F. and Prescott, E. C.. “Test of an Adaptive Regression Model.Rev. Econ. and Statis. 55(May 1973):248–56.CrossRefGoogle Scholar
Cooley, T. F. and Prescott, E. C.. ”The Adaptive Regression Model.Internat. Econ. Rev. 14(June 1973).CrossRefGoogle Scholar
Cooley, T. F. and Prescott, E. C.. ”Varying Parameter Regression: A Theory and Some Applications.” Ann. Econ. and Soc. Meas. 2(Oct. 1973).Google Scholar
Cooley, T. F. and Prescott, E. C.. ”Estimation in the Presence of Stochastic Parameter Variation.” Econometrica. 44(Jan. 1976) p. 170.CrossRefGoogle Scholar
Hsiao, C.Some Estimation Methods for a Random Coefficient Model.Econometrica. 43(March 1975).CrossRefGoogle Scholar
Kmenta, Jan. Elements of Econometrics. New York: Macmillan Publishing Company, Inc., 1971, chap. 12.Google Scholar
Maddala, G.S., Econometrics. New York: McGraw-Hill Book Company, 1977, chap. 17.Google Scholar
Simon, Hermann. “Dynamics of Price Elasticity and Brand Life Cycles: An Empirical Study.J. Market. Res. 16(1979):439–52.CrossRefGoogle Scholar
Swamy, P. A. V. D., “Efficient Inference in a Random Coefficient Regression Model.Econometrica. 38(1970):311–23.CrossRefGoogle Scholar
Ward, Ronald W. and Kilmer, Richard L.. “The U.S. Citrus Subsector: Organization, Behavior and Performance.” N. C. 117 Mono. Ser., 1979. In press.Google Scholar
Ward, Ronald W. and Myers, Lester. “Advertising Effectiveness and Coefficient Variation Over Time.Agr. Econ. Res. 31(Jan. 1979).Google Scholar