引力模型,其起源於物理學中的牛頓力學第一定律「萬有引力法則」。其萬有引力法則敘述,認為兩物質間必存在引力是以彼此質量成正比,且與彼此距離成反比之特性。而Tinbergen(1962)利用引力模型的概念,即是利用國家GDP來替代引力模型中物質的質量,用國家間距離來代替物質之間的中心距離。來探討兩國的雙邊貿易流量規模與其各自的經濟規模成正比,與兩國地理距離(Geographical distance)成反比的關係,而經過近幾十年的發展,引力模型已經在國際貿易研究中獲得相當的成就與肯定,尤其被廣泛地運用於測算貿易潛力、分析貿易模式、及估算不同貿易集團間貿易壁壘的效果等領域。 本研究旨在評估在國際上普遍採用非關稅貿易障礙措施下,我國農產品外銷歐盟之市場潛力,藉由研析歐盟國家自1995年至2003年的經濟自由度指標,彙整歐盟各國名目GDP與經濟水平數據,再加上各國的信貸環境指標數據,將橫斷面數據和時間數列資料揉合處理,並配合引力模型實證,進而研議進入歐盟市場之策略。 根據實證結果顯示,針對經濟水平越高之國家,如法國、英國等,雖然其市場規模龐大,但在市場吸引潛力上,反倒不如西班牙、希臘;另在非關稅障礙因素上,進口成本的高低較進口法規、條例等規定影響還來的明顯重要許多。因此在政策建議上,希冀以降低通關成本、時間等待、產品檢驗為貿易交涉之主要目的,開放配額與產品標示等為次要條件,利用台灣農產品高品質、高技術的特色推銷至國際市場上。
The gravity model for trade is analogous to Newton's gravity law in mechanics: the gravitational pull between two physical bodies (in Newtons) is proportional to the product of each body's mass (in kilograms) divided by the square of the distance between their respective center of gravity (in metres).The gravity equation is a popular formulation for statistical analyses of bilateral flows between different geographical entities. In 1962 Jan Tinbergen proposed that roughly the same functional form could be applied to international trade flows. Gravity models have been used extensively in recent years to try to quantify potential trade levels, particularly with transition countries. This paper focuses the discussion on the variables of the model, with a specific emphasis on agriculture trade flows with non-trade barriers and the agriculture market potential in European Union. The purpose of this study is to find the enter EU market strategies by research the EU15 Economic Freedom of the world(EFW)index.We consistently estimate the yearly GDP, international trade tax revenues, hidden import barriers, costs of importing, and risk of the credit market regulation efforts of these EU15 governments for the late 8 years. We further examine the factors that affect the level of agriculture trade efforts by employing a Panel data model using the data from 1995 to 2003.