Essays on total evaluation of Colombia wheat import demand, forecast evaluation of the United States total wheat trade in Colombia, and the impact of price changes and trends on demand for meat in Nigeria

Scope and method of study. The purposes of this study are: (1) Determination of Colombian total wheat import demand and effect of seasonality especially from the major exporters such as the United States and Canada. (2) Forecasting the United States total wheat exports to Colombia with the specific objective to develop forecasting models that incorporate economic variables such as wheat price and exchange rates on monthly trade flows in Colombia's wheat market. (3) Estimating the responsiveness of demand for meat to variations in prices and incomes. In addition, to determine whether demand for meat is price-elastic on the basis of food demand data covering the period of 1980 to 1999, and provide recommendations for policies that can help create more stable meat consumption and prices for the nation.; Findings and conclusions. (1) All the expenditure elasticity estimates are statistically different from zero at α = 0.05 level indicating that wheat import demand is a normal good. The seasonality parameters are almost all negative and significant, indicating substantial seasonal effect for Canada. The Colombia wheat import demand for the United States, Canada and rest of the world is elastic with respect to own-price. (2) It was established that United States total wheat exports to Colombia can be modeled as transfer function ARIMA(1,1,1)(1,1,1)12 process. (3) All demand coefficients, especially those of own-price, display the appropriate sign with a plausible magnitude. Most of the variation in the demand for individual meat and fish products is explained by the variation in the explanatory variables indicated. Parameter estimates for Nigeria meat demand system using the AIDS Model were significant at the 10 and 15 percent levels of significance. The results of this estimation broadly coincide with those obtained using the double-log demand model specification and previous studies.