實證結果發現，在2004至2012年期間，出口國FDI在低於門檻值時，為影響貿易流量的因素之一，進口國的GDP規模不論在出口國GDP門檻值上下均能促進貿易流量增長，高於門檻值時影響更為顯著，而進口國人均所得變數對貿易流量則無顯著影響；另外，在虛擬變數的部分，實證結果顯示，歐盟區域經濟整合在門檻值之下時具有顯著的貿易創造效果，但並無顯著存在貿易轉移效果。 A model of Custom Union which was set up at the very first beginning in the founding process of the European Union had drawn the economist’s attention to the trade effects of regional economic integration. From then to now, the European Union has become the most influential regional economies in the world and also surfed on the trend of liberalization of International trade. In addition to the Doha Round of World Trade Organization trade negotiations, the European Union has signed several Regional Trade Agreements to expand the market overseas. This paper traces the development of European Union and use the gravity model with dummy variable to analyze the trade effect. And this model also uses the GDP of exporter as a threshold variable to analyze the major factors affecting trade flows.
Based on the results of this study during the period 2004-2012, the regional economic integration of European Union brings significant trade creation effect but no clear trade diversion effect. The results also show that the major factors influencing trade flows are the GDP of the importer and the FDI of the exporter while the GDP of the exporter as threshold variable. Whether the GDP of the exporter is above or below the threshold value, the GDP of the importer has a positive influence to the trade flows. When the GDP of the exporter is below the threshold value, EU regional economic integration brings trade creation but no trade diversion.