ECFA早收清單影響效果評估：以石斑魚出口為例

A Policy Evaluation of the Impact of the Early Harvest Plan on ECFA: A Case Study of Grouper

ECFA是台灣簽署自由貿易協議中最重要的一項，其中有些早收清單中先降稅的項目，可以供吾人做為政策評估的參考。石斑魚為台灣重要的農產品出口項目，且其原先的關稅稅率較高，因此本研究選取台灣石斑魚作為政策評估對象。本文先建立一個誤差修正模型 (vector error correction model, VECM)，並採用2003年1月至2016年3月的月資料，來分析短期之下台灣石斑魚出口量與平均出口價格偏離長期均衡時可能的調整方向、調整速度以及原因，最後再以變異數分解分析ECFA早收清單降稅對於台灣石斑魚出口量的影響程度。 Johansen共整合檢定結果顯示，台灣石斑魚出口量與各總體經濟變數之間具有長期的均衡關係。實證結果顯示中國大陸對石斑魚需求所得彈性很大，估計為8.942；台灣石斑魚與中國大陸石斑魚為替代關係，估計兩者替代彈性為0.002。最後，衝擊反應函數則顯示，關稅的下降對於台灣石斑魚外銷至中國大陸有著持續性的正向影響，意即降低關稅有助於台灣石斑魚出口至中國大陸，但此一正向影響的效果會隨著時間而下降。

 

ECFA is one of the most important FTAs for Taiwan, and it is meaningful to make a policy evaluation by applying the items in the early harvest plan. Grouper is an important exporting item from Taiwan to mainland China. Moreover, since the original tariff rate of the grouper in mainland China is quite high, the impact of the tariff reduction should be large. Applying the vector error correction model and using the monthly data from January 2003 to March 2016, we analyze the adjustment direction, adjustment speed, and the reasons for the adjustment when the export of grouper from Taiwan and mainland China deviates from its long-term trend. Then we apply forecast error variance decomposition to estimate the size of the tariff reduction on the export of grouper from Taiwan to mainland China. The Johansen cointegration test shows that the export of grouper from Taiwan to mainland China has a long-term equilibrium relation with other important variables. Moreover, the empirical results show that the income elasticity of demand for imported grouper in mainland China is 8.942; while the elasticity of substitution between grouper of Taiwan and grouper of mainland China is 0.0028. Finally, the impulse response function shows that tariff reduction has a positive impact for groupers of Taiwan exporting to mainland China, however the impact will become smaller as time goes by.