中文摘要
本文在一个异质性企业可选择中介融资或直接融资的模型中，定量分析了提高资本要求的宏观经济影响。异质性银行与其他银行及债券市场竞争，利用受保险存款和成本高昂的权益资本（受最低资本资产比约束）为贷款融资，并监督借款人。研究发现，更严格的资本要求能够减少代价高昂的银行倒闭，同时对关键宏观经济总量的影响很小，并且将资本要求提高至高于当前水平可以改善福利。三种主要力量促成了这些结果：第一，尽管在给定净资产水平下，银行会在资本要求收紧时削减贷款供给，但在均衡状态下银行净资产会上升，从而缓解这一影响；第二，来自非银行部门的激烈竞争约束了银行对监管收紧的贷款反应；第三，公司制企业的替代行为抵消了银行贷款供给收紧所导致的债务融资下降中的很大一部分。由此可以推断，与资本要求收紧相关的适度成本几乎全部集中在依赖银行融资的非公司制部门。
Abstract
Abstract I quantitatively analyse the macroeconomic impacts of raising capital requirements in a model in which heterogeneous firms may choose either intermediated or direct finance. Heterogeneous banks compete with other banks and the bond market, fund loans with insured deposits and costly equity (subject to a minimum capital-to-asset ratio), and monitor borrowers. I find that tighter capital requirements reduce costly bank failures while having only small effects on key macroeconomic aggregates, and that raising capital requirements above current levels can be welfare-improving. Three main forces give rise to these results. First, even though banks cut loan supply for a given level of net worth under a tighter capital requirement, in equilibrium banks’ net worth rises to dampen this effect. Second, intense competition from the non-bank sector disciplines banks’ lending responses to tighter regulation. Third, substitution by corporate firms offsets much of the decline in debt financing associated with tighter bank loan supply. As a corollary, almost all of the modest costs associated with tighter capital requirements are concentrated within the bank-dependent non-corporate sector.