| Author(s) | Abdulaziz A. Al Zoom |
| Affiliation | Department of Agricultural Economics, College of Agriculture King Saud University, Riyadh, Saudi Arabia |
| Title | Time Series Analysis of the Onion WhoPrices in Saudi Arabialesale |
| Source | Journal of King Saud University. Agricultural Sciences. Volume 14, No 2. (2002/1422) |
| Abstract | This paper is aimed at analyzing the quarterly time series data for the dry onion average wholesale prices during the years 1990-1997. In order to obtain a prediction of future onion wholesale prices, two econometric models have been built. The first is based on dummy variables, while the second on some triangle functions. Further, the effect of the general trends and price seasonality has been removed from the model. Also, the cyclical trends that might appear in some time series data are assumed to have no effect on the models, because of its short length. The study applies Box-Jenkins method to analyze the random errors and its components of auto regression and moving average. Further, the study also applies. Theil inequality coefficient to test the prediction ability of the models. In general, the study finds the models to have second ordered auto correlation and good predicted values. In addition, the measured seasonal factors show that second and third quarters are likely to have less than average prices, while first and fourth quarters to have a level above the average prices. |
