中文摘要
自20世纪90年代末以来,美国产品市场日益集中,表现为加成率上升、企业进入减弱和生产率增长放缓。本文研究美国银行业的整合是否促成了这些趋势。在实证部分,我表明更高的银行集中度与产品市场加成率上升、企业进入减少以及市场势力向大型在位企业重新配置相关联。我在一个包含银行不完全竞争与企业异质性的定量内生增长模型中解释这些模式。关键机制是不断扩大的存贷利差:即使利率水平下降,银行市场势力的增强也会扩大依赖银行融资的小企业所面临的借贷成本与依靠内源融资的大企业所面临的资金机会成本之间的楔子,使竞争向大型在位企业转移,并削弱创新激励。在校准的反事实分析中,2000年以后银行集中度的上升解释了产品市场集中度上升的约14%和生产率增长放缓的约5%。
Abstract
U.S. product markets have become more concentrated since the late 1990s, with higher markups, weaker entry, and slower productivity growth. This paper studies whether consolidation in the U.S. banking sector has contributed to these trends. Empirically, I show that higher bank concentration is associated with rising product market markups, lower entry, and a reallocation of market power toward large incumbents. I interpret these patterns in a quantitative endogenous growth model with imperfect bank competition and heterogeneous firms. The key mechanism is a widening loan-deposit spread: even as interest rate levels decline, greater bank market power increases the wedge between the borrowing costs faced by small bank-dependent firms and the opportunity cost of funds faced by large internally financed firms, shifting competition toward large incumbents and weakening innovation incentives. In calibrated counterfactuals, the rise in bank concentration explains about 14% of the increase in product market concentration and 5% of the slowdown in productivity growth over the post-2000 period.