公司治理理論預期代理成本將影響公司績效，而本文旨在探討25家台灣上市櫃銀行業，以代理成本角度，資本結構變動可否降低代理成本，因此提高銀行業績效論點推論。並使用Tobin's Q作為銀行績效衝量指標，不同於以往用會計基礎衝量指標，期能更有效反應銀行未來的營運狀況。並用反面因果關係從銀行績效到資本結構的一聯立方程模型，使用二階段最小二平方法(2SLS)來分析，研究結果顯示經營績效對負債比率具有正向顯著影響，而負債比率對經營績效則具有正向影響關係。在代理成本之相關變數上，銀行規模對經營績效為負向顯著影響，對負債比率則為正向顯著影響。而銀行風險對經營績效、負債比率皆為正向顯著影響。市場集中度則對經營績效據有顯著影響效果。管理者持股對經營績效為負向顯著影響。外部大股東持股對經營續效為正向顯著影響。 The main objective of this research is to discuss the expected agency costs based on the company governance theory. In this research, twenty five (25) selected banks listed on the TSE (Taiwan Stock Exchange) were selected to evluate their performance. From the standpoint of agency costs, this research made a primary assumption on the following: the change of bank capital structure can decrease agency costs, and then enhance the banks' performance.Different from traditional accounting- based indicators, the research used the performance indicators which are derived from Tobin's Q theory in order to examine the banks' future operations. The research also employed the reverse cause-effect relations to derive the simultaneous equations from bank performance to capital structure. The equations apply two-step least-squares (2SLS) method to analyze the indicators gathered from the banks. The research results showed that the relation between bank performance and debt ratio had a positive significance. From the perspective of variables on agency costs, there was a negative and significant relationship between bank scale and bank performance while the relationship between bank scale and debt ratio was significantly positive. Among other indicators, bank operation risk had a significantly positive impact on bank performance and debt ratio and market concentration rate had a significantly positive effect on bank performance. The bank supervisor holding bank share was significantly negatively related to the bank performance while bank share holders from market was significantly and positively related to bank performance.
