Forecasting the Prices of Rubber Smoked Sheets Level 3

Abstract

The objective of this study is to construct the appropriate forecasting model for the prices of rubber smoked sheets level 3. The data gathered from the website of Office of the Rubber Replanting Aid Fund during January 2004 to December 2012 of 108 values are used and divided into 2 sets. The first set has 102 values from January 2004 to June 2012 for constructing the forecasting models by the methods of Box-Jenkins, damped trend exponential smoothing, simple seasonal exponential smoothing, combined forecasts that weighted by the least squares method, and combined forecasts that weighted by the proportion of the value in the
eigenvector from the principal component analysis. The second set has 6 values from July to December 2012 for comparing accuracy of the forecasts via the criterion of minimum root mean squared error (RMSE). The result shows that the most accurate method is the combined forecasts that weighted by the least squares method.