A traffic-jam theory of growth
研究了金融发展与经济增长之间的倒U型关系，发现金融过度发展会通过加剧创新资源竞争而拖累技术进步，对美国经济的校准显示金融对增长的负面影响虽存在但量级很小。
We investigate the growth–finance nexus in an endogenous growth model with search frictions and congestion effects in credit and innovation markets. The interaction between these two frictions generates a non-monotonic, inverted-U relationship between financial development and growth. Financial development exerts two opposing forces: a direct positive finance channel by easing access to funding and an indirect negative congestion channel, as greater financial activity draws more firms into R&D competition for scarce innovation resources. The resulting hump-shaped pattern implies that excessive financial development can slow technological progress. The mechanism remains robust when allowing for firm heterogeneity that can generate composition effects. In a calibration close to the U.S. economy, the impact of finance on growth is negative but quantitatively small, consistent with the observation that, over the last century, most advanced economies have experienced financial expansion alongside nearly constant GDP growth rates.