摘要 本文主要目的是採用不同的匯率頻率資料 (日資料及月資料),以單變量Box-Jenkins 時間列序模型做為預測方法,選取標的物為美元兌新台幣、日圓、歐元的即期匯率,找出最適預測模型,並以誤差均方根(RMSE)、平均誤差絶對值(MAE)、平均絶對誤差百分比值(MAPE)做為衡量標準來評估模型樣本外的預測績效,並檢視高頻率資料預測能力是否較低頻率資料預測為佳。 實證分析得到之結果顯示,利用三種計算誤差值之統計量來做為衡量指標(RMSE、MAE、及MAPE),日資料之預測誤差值都比月資料來的小,反應出高頻率資料之預測能力確實較低頻率資料為佳。在不考慮資料取得成本時,對於公司決策者或一般投資大眾在做外匯市場實務操作時,建議可以高頻率資料來建立預測模型,就能有效掌握外匯市場的動向,減少決策錯誤的機率,可以達到投資、套利、避險及減少匯兌損失的目的。
Abstract The purpose of this paper to adopt different frequency data(daily and monthly data). This paper use forecasting models, which is the univariate time series model of Box-Jenkins ARIMA models as a forecasting approach. Using the spot exchange rates between US Dollar against New Taiwan Dollar、Japanese Yen、Euro Dollar as our empirical data, and try to find a reasonable and efficient models for predicting the exchange rates of models. Finally, this paper will employ RMSE、MAE、MAPE as our standard evaluating principles, and to evaluate their forecasting performance in out-of-sample models. And inspected that high frequency whether to compare the low frequency best forecastability. The result indicates that the three kind of measurement tools(RMSE, MAE, and MAPE). Conclusion, We find that prediction errors of daily data are small relatively to the monthly data. Therefore, we compare in the high frequency data to the low frequency best forecastability. Exclude to obtain data cost, enterprise decision-making or individual investor practice operation in the foreign exchange market, may be to use high frequency data to build forecasting models. if we can effectively control the foreign exchange market of trend, and to reduces the decision-making wrong probability, and furthermore, to achieve the investment、arbitrage、hedge, and we can reduce the risks of the exchange rates.