本文應用門檻迴歸模型(threshold regression model)檢驗台灣進口物價是否因匯率變動幅度不同，而產生不同程度的匯率轉嫁。實證結果顯示，當匯率變動幅度小於3%時，有顯著的匯率轉嫁；反之，則匯率轉嫁不顯著。我們認為上述不對稱匯率轉嫁的可能成因為菜單成本的存在。當匯率變動時，出口商必須在調價所產生的菜單成本，與不調價對其價格競爭力的減損中，進行權衡取捨(trade-off)。因此，出口商唯有在匯率變動幅度夠大時，才會因應匯率變動進行調價。我們並透過理論模型嚴謹說明菜單成本存在時，上述的匯率「不對稱轉嫁」現象。

This study investigates whether there is an asymmetry in exchange rate pass-through using threshold regression technique. We found significant evidence for the pass-through effect only when the changes in exchange rates are smaller than 3%. The asymmetry is consistent with the predictions from a simple theory where altering prices to accommodate exchange rate fluctuations by exporters may incur fixed menu cost. Hence, despite a loss in competitiveness, exporters tend to maintain their exporting prices when the degrees of exchange rate movements are mild, resulting in the observed exchange rate pass-through.