本文利用經濟部能源局的油價資料，透過誤差修正模型（ErrorCorrection Model）分析國內油品價格反映原油成本變化的速度，以檢視汽油市場是否存在價格不對稱的現象？實證結果並不支持：汽油價格會以較快速度反映原油成本增加，或是以較慢速度反映原油成本下跌。此一結果與輿論看法並不相同，其原因應是政府迫於輿論壓力所採行的低油價政策與台塑進入市場所形成的價格競爭。

This article investigates price asymmetry by using an ECM (Error Correction Model) to see whether gasoline prices respond faster to cost increases than they do to decreases. The data are obtained from the energy price dataset of the MOEA (Minsgtry of Economics Affairs, Taiwan). In contrast with the public opinion, the evidence shows that gasoline prices did not adjust more quickly to cost increases than to decreases. The fact might be owing to the government's low energy price policy and the intense competition following the entry of Formosa Petrochemical Co. into gasoline market.