本研究在不完全競爭市場結構下，推導利潤最大化一階條件，配合調整技術效率後的成本函數與份額方程式，形成五條聯立迴歸模型。收集民國70年至87年我國22家老銀行資料，檢定銀行產業究竟是否屬於不完全競爭市場結構？實證分析結果，發現台灣銀行廠商間存在策略反應行為；民國80年起開放新銀行申設，的確成功地導引此產業朝向完全競爭之途邁進。如此，過去在完全競爭市場結構假設下，相關研究結果，可能尚有商榷必要。 Under the assumption of profit maximization, this article derives thefirst-order conditions for each banking firm choosing two outputquantities. Those optimal conditions together with the technicalefficiency adjusted cost function and share equations form the systemof five regression equations that is applied to a panel of data fromTaiwan's banking industry for the period of 1981 to 1998. Evidence isfound that both markets of investments and loans are characterized bysignificant strategic interaction and that the financialliberalization starting from 1991 does increase the degree ofcompetition in the two markets. This appears to disprove previousstudies in this area based on the assumption of perfect competition.
