共同所有權，放款市場競爭，與銀行事後監督誘因

COMMON OWNERSHIP, CREDIT MARKET COMPETITION, AND BANK MONITORING

本研究延伸線形城市空間競爭模型，探討共同所有權如何影響銀行事後監督誘因、社會福利、與資本適足法規。機構法人投資人共同持有銀行部分所有權，銀行付出努力監督企業主執行計畫案以提高放款組合成功機率，並設定放款利率競爭企業主申貸。當共同所有權比例上升時，將提高銀行放款利率與事後監督誘因；當企業主計畫案成功之報酬與銀行倒閉之社會外部成本夠大，且銀行事後監督技術成本夠小，共同所有權比例上升可提高社會福利。此外，資本適足法規趨嚴將提高銀行放款利率與事後監督誘因，而共同所有權比例上升則削弱資本適足法規趨嚴之效果；若金融監管機構能夠設立資本適足法規以極大化社會福利，當共同所有權比例上升時，應調降資本適足法規。

We employ a linear spatial model to explore how common ownership affects banks’monitoring incentives, social welfare, and capital requirements. Entrepreneurs are uniformly distributed on a linear city and each of them has no resources but one risky project. Two banks are located at the two endpoints and compete for entrepreneurs. They are also endowed with a technology that enables them to monitor borrowers to increase the successful probability of their loan portfolios. Furthermore, the two banks have partial common ownership and thus determine loan rates and monitoring effort simultaneously to maximize the ownership-averaged expected profits. We find that an increase in common ownership induces the banks to increase their loan rates and monitoring effort. Moreover, when the return on the project, if successful, and the social cost of bank default are high, and the monitoring cost is low, an increase in common ownership improves social welfare. An increase in capital requirements then induces the banks to raise their loan rates and monitoring effort; however, an increase in common ownership mitigates the effects from an increase in capital requirements. Lastly, an increase in common ownership reduces optimal capital requirements.