貿易的全球化已經使得各國的機動車輛價格差距大幅縮小,任兩個國家的同等機動車輛的價格比值已多不超出1~2倍的範圍。不過,相對於車輛價格的拉近,交通運輸所使用的汽油價格在任兩個國家間卻仍可能相差達到1~150倍。由於汽油價格的高低可能影響到國家間的相對競爭力,因此從全球經貿互動的角度來思考,掌握導致各國間汽油價格明顯不同的因素,再尋思一國合理的汽油價格水準為何,將是知己知彼並進而維持國家產業競爭能力的關鍵工作。 本研究先由理論探討造成各國汽油價格差異的可能因素,再透過實證分析檢證造成各國間存在價格差異的真正因素為何。理論上,汽油價格的差異主要來自於政策上的考量,而政策的工具則多以稅制來影響汽油價格;除此之外,影響汽油價格的因素部分也來自外部成本的考量。至於在實證方面,本研究採用包含歐盟15個國家與美國、台灣共17個國家的資料,並採用結合橫斷面與時間序列資料之Panel Data Model 進行分析。經過模型設定檢定後,本研究發現固定效果模型並加入異質變異與自我相關修正的估計方法,是本研究最適當的實證模式。 本研究實證結果顯示,影響各國汽油價格的因素主要與政府消費支出、政府負債、經濟成長(國內生產毛額)、每人平均國民所得等有關。另外,外部性的因素包括車輛擁塞程度、交通道路意外人數及二氧化碳排放成長等,以及各國石油進口依存度,也會影響各國的汽油價格。基本上,政府消費支出與汽油價格呈現反方向的變動,而政府負債與汽油價格間則呈現正相關,顯示當一國政府負債增加時,政府多會以提高汽油相關稅率來挹注。至於國內生產毛額與平均每人國民所得反映了一國的經濟水準,因此與汽油價格也呈現顯著的正向關係。另外,車輛擁塞度與交通道路意外人數與汽油價格也呈現正向關係;而能源進口依存度愈高,也會因成本提高導致汽油價格升高。目前我國汽油價格與他國相比有偏低的現象,將可能不利於高效率能源技術的發展,也使得整體能源效率偏低。因此,是否讓油品價格合理反映成本之變動,不只將會影響到產業的能源生產力,也可能會影響到我國能源技術產業之國際競爭力。
The globalization of world trade has leveled motor vehicle price all over the world to such an extent that the price ratio for equivalent vehicles no longer exceeds about 1 to 2 between any two countries. However, transport gasoline price in different countries still differ on a scale of as much as 1 to 150. This paper examines a number of considerations from the theory of public finance that may explain these differences and explores empirically the factors that contribute to these differences. Theoretically, we found that differential tax policies between counties are the main reason that causes the difference in gasoline price among different countries. Empirically, by using the data set containing gasoline prices for 17 countries (15 EU, US, and Taiwan) spanning from 1999 to 2004, and by applying fixed effect model with FGLS estimation method, we found that the factors that contribute to the significant differences in gasoline price include government expenditure, government debt, income, as well as car density and road casualties. Environmental situations ( emissions) and the dependency in imported oil are also found to be significant factors that may cause the gasoline price to differ. The results from our empirical analysis suggest that raising gasoline price may improve the quality of the environment to some extent, which indicates that designing suitable policy for gasoline price should be a good way of achieving sustainability of the economy.