Main Article Content
The aim of this research is to compare the forecasting models for the price of daily ground pork with 4 statistical methods, namely, the Box-Jenkins method, Holt’s exponential smoothing method, Brown’s exponential smoothing method, and the damped trend exponential smoothing method. The time series for the price of daily ground pork were gathered from the website of Kasetprice from July 6, 2021 to July 5, 2022 (365 days) which was divided into 2 datasets. The first dataset from July 6, 2021, to June 25, 2022 (355 days) was used for constructing the forecasting models. The set of the last 10-day from June 26 to July 5, 2022, was used to evaluate the accuracy of the forecasting models via the use of the lowest mean absolute percentage error (MAPE) and root mean squared error (RMSE). The results showed that the damped trend exponential smoothing method had the lowest MAPE and RMSE values and had a forecast model as following.
Where m = 1 represents June 26, 2022. For the Box-Jenkins method and Holt's exponent smoothing method, there were slightly higher MAPE and RMSE values. The forecast models were shown in the following order:
Where represents the time series at time t – j,
Where m = 1 represents June 26, 2022. However, the average forecast values of the three methods were not different at 0.05 significance level. Therefore, the users can use any model to forecast the future price of daily ground pork.
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