東協加一FTA的貿易創造和貿易移轉及其異質性探討

Abstract

本研究透過引力模型，分析東協-中國FTA、東協-日本FTA、東協-韓國FTA三個東協加一FTA的貿易創造及貿易移轉效果，以及貿易協定間貿易效果的異質性。本研究使用2000年至2020年東協十國、中國、日本、韓國以及東協前17大貿易夥伴國家，分別對所有其他國家的貿易面板資料，並於模型中加入年份固定效果(year fixed effect)、國家雙邊固定效果(country-year fixed effect)，控制因遺漏變數偏誤產生的內生性問題，估計上，使用卜瓦松偽最大似然估計(Poisson pseudo-maximum-likelihood, PPML)方法估計非線性模型，處理過往文獻中對數線性模型所存在誤差項異質變異的問題，以獲得不偏及一致的估計結果。

針對貿易效果異質性的探討，本研究除了將總貿易值拆分為擴展邊際及集約邊際的二元邊際外，也於模型中加入貿易效果與高所得國家的交乘項、動態逐年效果，更進一步分成不同產業，剖析東協加一FTA的效果異質性。實證結果發現整體上東協-中國FTA產生最大的純貿易創造效果，東協-韓國FTA效果其次，而東協-日本FTA則是對成員國的貿易造成負面影響，且三個東協加一FTA皆不存在貿易移轉的情形。此外，結果也顯示各東協加一FTA的貿易效果確實存在於二元邊際、貿易對象所得水準及逐年動態的異質性。本研究的發現將使政府機構對於東協加一FTA相關貿易政策的成效，有更完整的評估。

This study employs a gravity model to analyze the trade creation and trade diversion effects of three ASEAN+1 FTAs: ACFTA, AJCEP, AKFTA, as well as the heterogeneity of trade effects among these agreements. Using panel trade data from 2000 to 2020, the study covers bilateral trade between the ten ASEAN countries, China, Japan, Korea, and ASEAN’s 17 largest trading partners with all other countries. The model includes year fixed effects and country-pair fixed effects to address endogeneity caused by omitted variable bias. For estimation, the study applies the Poisson pseudo-maximum-likelihood (PPML) method to account for heteroskedasticity issues.

To explore the heterogeneity of trade effects, the study decomposes total trade value into intensive and extensive margins, incorporates interaction terms between trade effects and high-income countries, includes yea dynamic effects, and further differentiates by industry to analyze sectoral variations in the impact of ASEAN+1 FTAs. The empirical results show that the ACFTA has generated the largest pure trade creation effect, followed by the AKFTA, while the AJCEP has had a negative effect on trade among its members. Additionally, no evidence of trade diversion is found for any of the three FTAs. The findings also confirm that the trade effects of ASEAN+1 FTAs vary significantly across margins, income levels of trade partners, and over time. These insights provide a more comprehensive assessment of the effectiveness of ASEAN+1 FTA-related trade policies for policymakers.