摘 要本研究檢視銀行產品市場競爭與公司治理的關係，以及不同的競爭衡量指標是否有不同的結果，使用2007至2022年本國銀行年資料為樣本。銀行競爭指標包括：以總資產、總營收、總放款及總存款等市占率為基礎所計算的賀芬德指數及前四大市占率總和，以及廣告費用密集度和邊際營業利潤。公司治理使用由董監事席次、獨立董監事比率、內部人持股以及金融機構持股所形成的綜合治理指標。結果發現廣告費用密集度及邊際營業利潤都與市場集中度指標呈現中低度相關或相關方向相反，故不同的競爭指標或許衡量從不同角度觀察的市場競爭狀況。市場競爭與公司治理關係的實證結果指出，屬於市場集中度的兩個競爭指標以及邊際營業利潤都與銀行的公司治理無顯著關係，可能是因為市場競爭與公司治理之互補與替代的關係同時存在而導致相關性抵銷。唯獨以廣告費用密集度與公司治理呈現負相關，故兩者為替代關係；銀行市場越競爭，則越不需要積極的公司治理。本研究支持市場競爭的光明面大於黑暗面。 ABSTRACTThis study examines the relationship between competition in the banking product market and corporate governance, and whether different competition metrics have different results. The sample is the domestic bank's annual data from 2007 to 2022. Bank competition indicators include: the Herfindahl-Hirschman Index (HHI) calculated based on the market share of total assets, total revenue, total loans and total deposits, and the sum of the top four market shares, as well as advertising expense intensity and operating profit margin. Corporate governance uses a comprehensive governance index formed by the number of directors and supervisors, the ratio of independent directors and supervisors, insider shareholding and financial institution shareholding. The results show that both the advertising expense intensity and the operating profit margin have a medium-to-low correlation or and opposite correlation with the market concentration index, so different competition indexes may measure the market competition from different perspectives. The empirical results of the relation of market competition and corporate governance point out that the two competition indicators belonging to market concentration and operating profit margin have no significant relationship with bank corporate governance, which may be due to the complementary and substitutable relationship between market competition and corporate governance being cancelled. Only advertising expense intensity and corporate governance are negatively correlated, so the two are substitutes; the more competitive the banking market is, the less need for active corporate governance. This study supports that the bright side of market competition outweighs the dark side.
