本研究強調關稅的差異性，以廠商調查的方式實地了解東協加一、東協加三自由貿易區成立對我國出口的影響。研究結果顯示，我對東亞 國家的出口，適用當地進口零關稅的產品占五成以上，預估將不受影響；在非零關稅產品部分，其平均稅率介在4％-7％，對廠商恐將造成相 當程度的負面衝擊，惟若該產品係供作當地加工後再出口，則可享有出口退稅，實質稅率亦為零。綜合評估衝擊較大的產業可能為石化業、鋼 鐵業，而電子、光電產業的影響應屬有限。

This paper assesses the impact on Taiwan exports from the establishment of the "ASEAN plus one" and "ASEAN plus three" FTAs, in particular in the area of differential tariff rates between members and non-members. The author conducted interviews with firms to obtain first-hand information oand quantitative evaluation on potential changes in exports. Survey results indicate that among Taiwan's exports to East Asia, over 50 percent are subject to zero tariff rate and therefore will not be affected by the introduction of differential rates when the FTAs enter into effect. For categories that do not enjoy zero tariff, for which the tariff rates average between 4 and 7 percent, Taiwanese firms will face a substantial negative impact. However, products that are processed by FTA members and re-exported will enjoy a tariff rebate and thus in effect be subject to zero tariff. This study finds that the petrochemical and steel industries are likely to suffer the hardest impact, while the electronics and LCD industries should experience only a limited impact.