¹Universidad EAFIT, Departamento de Economía, Medellín, Colombia. Associate professor. Email: aramir21@eafit.edu.co

The main objective in this paper is to obtain reliable long-term and short-term elasticities estimates of the beef demand in Colombia using quarterly data since 1998 until 2007. However, complexity on the decision process of consumption should be taken into account, since expenditure on a particular good is sequential. In the case of beef demand in Colombia, a Multi-Stage process is proposed based on an Almost Ideal Demand System (AIDS). The econometric novelty in this paper is to estimate simultaneously all the stages by the Generalized Method of Moments to obtain a joint covariance matrix of parameter estimates in order to use the Delta Method for calculating the standard deviation of the long-term elasticities estimates. Additionally, this approach allows us to get elasticity estimates in each stage, but also, total elasticities which incorporate interaction between stages. On the other hand, the short-term dynamic is handled by a simultaneous estimation of the Error Correction version of the model; therefore, Monte Carlo simulation exercises are performed to analyse the impact on beef demand because of shocks at different levels of the decision making process of consumers. The results indicate that, although the total expenditure elasticity estimate of demand for beef is 1.78 in the long-term and the expenditure elasticity estimate within the meat group is 1.07, the total short-term expenditure elasticity is merely 0.03. The smaller short-term reaction of consumers is also evidenced on price shocks; while the total own price elasticity of beef is -0.24 in the short-term, the total and within meat group long-term elasticities are -1.95 and -1.17, respectively.

Key words: Cointegration, Delta method, Demand system, Generalized method of moments, Monte Carlo Simulation.

El objetivo más importante de este artículo es obtener estimaciones confiables de las elasticidades de la demanda de carne de res en Colombia para el largo y corto plazo utilizando información trimestral desde 1998 hasta 2007. Sin embargo, las decisiones que toman los consumidores se enmarcan en un ambiente complejo, puesto que el gasto en un bien particular se realiza de forma secuencial. En el caso particular de la demanda de carne de res en la economía colombiana, se propone un Sistema Casi Ideal de Demanda Multinivel. La novedad econométrica en este artículo es estimar simulatáneamente todos los niveles del modelo mediante el Método Generalizado de los Momentos; esto permite obtener una matriz conjunta de covarianzas de todos los parámetros, y así utilizar el Método Delta para calcular las desviaciones estándar de las elasticidades estimadas de largo plazo. Adicionalmente, este enfoque nos permite obtener estimaciones de las elasticidades en cada nivel, pero también, elasticidades totales que incorporan la interacción entre los niveles. Por otra parte, la dinámica de corto plazo se estudia a través de la estimación conjunta de la versión en Corrección de Errores del modelo; de esta forma, ejercicios de simulación Monte Carlo son reaizados para analizar el impacto sobre la demanda de carne de res debido a perturbaciones en diferentes niveles del proceso de toma de decisiones de los consumidores. Los resultados indican que aunque en el largo plazo la elasticidad estimada de la demanda de carne de res con respecto al gasto total es 1.78, y la elasticidad estimada de la demanda con respecto al gasto en cárnicos es 1.07, la elasticidad de la demanda con respecto al gasto total en el corto plazo es solo 0.03. La reducida reacción en el corto plazo también está presente ante perturbaciones en el precio; mientras que la elasticidad precio propia total de la demanda de carne de res es -0.24 en el corto plazo, las elasticidades total y al interior del grupo de cárnicos para el largo plazo son -1.95 y -1.17, respectivamente.

Palabras clave: cointegración, método delta, método generalizado de los momentos, simulación Monte Carlo, sistema de demanda.

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References

1. Anderson, G. & Blundell, R. (1983), 'Estimation and hypothesis testing in dynamic singular equations systems', Econometrica 50, 1559-1571.         [ Links ]

2. Asatryan, A. (2003), Data Mining of Market Information to Assess at-Home Pork Demand, PhD thesis, Texas AM University.         [ Links ]

3. Barreira, M. & Duarte, F. (1997), An analysis of changes in Portuguese meat consumption., 'Agricultural Marketing and Consumer Behaviour in a Changing World', Kluwer Academic Publishers, p. 261-273.         [ Links ]

4. Blackorby, C. & Russell, R. (1997), 'Two-stage budgeting: an extension of Gorman's theorem', Economic Theory 9, 185-193.         [ Links ]

5. Caraballo, L. J. (2003), '?'Cómo estimar una funcion de demanda? Caso: Demanda de carne de res en Colombia', Geoenseñanza 8(2), 95-104.         [ Links ]

6. Chern, W., Ishibashi, K., Taniguchi, K. & Tokoyama, Y. (2003), Analysis of the Food Consumption of Japanese Households, 152, FAO Economic and Social Development.         [ Links ]

7. Clark, G. (2006), Mexican Meat Demand Analysis: A Post-NAFTA Demand Systems Approach, Master's thesis, Texas Tech University.         [ Links ]

8. DANE, 2007, 'Cuentas nacionales', http://www.dane.gov.co/daneweb_V09/index.php?option=com_content&view=article&id=128&Itemid=85. [Online; accessed March-2010]         [ Links ].

9. Deaton, A. & Muellbauer, J. (1980a), Economics and Consumer Behaviour, Cambridge: Cambridge University Press.         [ Links ]

10. Deaton, A. & Muellbauer, J. (1980b), 'An almost ideal demand system', The American Economic Review 70(3), 312-326.         [ Links ]

11. Edgerton, D. (1997), 'Weak separability and the estimation of elasticities in multistage demand systems', American Journal of Agricultural Economics 79(1), 62-79.         [ Links ]

12. Fousekis, P. & Revell, B. (2000), 'Meat demand in the UK: a differential approach', Journal of Agriculture and Applied Economics 32(1), 11-19.         [ Links ]

13. Fuller, F. (1997), Policy and Projection Model for the Meat Sector in the People's Republic of China, Technical Report 97-TR 36 , Center for Agricultural and Rural Development - Iowa State University.         [ Links ]

14. Galvis, L. A. (2000), 'La demanda de carnes en Colombia: un análisis econométrico', Documentos de Trabajo sobre Economía Regional 13. Centro de Estudios Económicos Regionales, Banco de la República.         [ Links ]

15. Gao, X., Eric, J., Gail, W. & Cramer, L. (1996), 'A two-stage rural household demand analysis: microdata evidence from Jiangsu Province, China', American Journal of Agricultural Economics 78(3), 604-613.         [ Links ]

16. Golan, A., Perloff, J. & Shen, E. (2000), 'Estimating a demand system with nonnegativity constraints: mexican meat demand', The Review of Economics and Statistics 83, 541-550.         [ Links ]

17. Gorman, W. (1957), 'Separable utility and aggregation', Econometrica 27(3), 469-481.         [ Links ]

18. Hayes, D., Wahl, T. & Williams, G. (1990), 'Testing restrictions on a model of Japanese meat demand', American Journal of Agricultural Economics 72(3), 556-566.         [ Links ]

19. Holt, M. & Goodwin, B. (2009), The almost ideal and translog demand systems, 15092, Munich Personal RePEc Archive - MPRA. Online at http://mpra.ub.uni-muenchen.de/15092/.         [ Links ]

20. Johansen, S. (1988), 'Statistical analysis of cointegration vectors', Journal of Economic Dynamics and Control 12(2-3), 231-254.         [ Links ]

21. Kwiatkowski, D., Phillips, P., Schmidt, P. & Shin, Y. (1992), 'Testing the null hypothesis of stationarity against the alternative of a unit root', Journal of Econometrics 54, 159-178.         [ Links ]

22. Liu, H., Parton, K., Zhou, Z. & Cox, R. (2008), 'Meat consumption in the home in China: an empirical study', Australian Journal of Agricultural and Resource Economics Online: . *http://aede.osu.edu/programs/anderson/trade/57HongboLiu.pdf         [ Links ]

23. MAFF, (2000), National Food Survey 1999, Annual Report , Ministry of Agriculture, Forestry and Fisheries of United Kingdom.         [ Links ]

24. Ma, H., Huang, J., Rozelle, S. & Rae, A. (2003), Livestock Product Consumption Patterns in Urban and Rural China, Working Paper , Research in Agricultural Applied Economics.         [ Links ]

25. Michalek, J. & Keyzer, M. (1992), 'Estimation of a two-stage LES-AIDS consumer demand system for eight EC countries', European Review of Agricultural Economics 19(2), 137-163.         [ Links ]

26. Moschini, G. (1995), 'Units of measurement and the stone index in demand system estimation', American Journal of Agriculture Economics 77, 63-68.         [ Links ]

27. Newey, W. & West, K. (1987), 'A simple positive semi-definite, heteroscedasticity and autocorrelation consistent covariance matrix', Econometrica 55, 703-708.         [ Links ]

28. Ng, S. & Perron, P. (2001), 'Lag length selection and the construction of unit root tests with good size and power', Econometrica 69(6), 1519-1554.         [ Links ]

29. Osho, G. & Nazemzadeh, A. (2005), 'Consumerism: statistical estimation of Nigeria meat demand', Journal of International Business Research 4(1), 69-79.         [ Links ]

30. Parikh, A. (1988), 'An econometric study on estimation of trade shares using the almost ideal demand system in the world link', Applied Economics 20, 1017-1079.         [ Links ]

31. Pashardes, P. (1993), 'Bias in estimating the almost ideal demand system with the stone index approximation', The Economic Journal 103(419), 908-915.         [ Links ]

32. Rastegari, S. & Hwang, S. (2007), 'Meat demand in South Korea: an application of the restricted source-differentiated almost ideal demand system model', Journal of Agriculture and Applied Economics 39(1), 47-60.         [ Links ]

33. Segerson, K. & Mount, D. (1985), 'A non-homothetic two-stage decision model using AIDS', The Review of Economics and Statistics 67(4), 630-639.         [ Links ]

34. Shenggen, F., Wailes, E. & Cramer, G. (1995), 'Household demand in rural China: a two-stage LES-AIDS model', American Journal of Agricultural Economics. 77(1), 54-62.         [ Links ]

35. Sulgham, A. & Zapata, H. (2006), A dynamic approach to estimate theoretically consistent US meat demand system, Research Paper , Annual Meeting of American Agricultural Economics Association.         [ Links ]

36. Wahl, T., Hayes, D. & Williams, G. (1991), 'Dynamic adjustment in the Japanese livestock industry under beef import liberalization', American Agricultural Economics Association 73(1), 118-132.         [ Links ]

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