How large is volatility due to large firms? We answer this question through both reduced-form analysis and a calibration exercise. First, we exploit time and spatial variation across German cities and show that i) higher concentration is associated with more persistent local business cycles, ii) local concentration Granger-causes local employment volatility. From a business cycle perspective, we find evidence in favor of granularity-driven recessions only. Next, we calibrate a structural model along the lines of Carvalho and Grassi (2019) and find that the more fat-tailed productivity distribution in bigger cities crucially depends also on the higher probability for firms to grow.

中文翻译：

---

商业周期的微观起源：来自德国大都市区的证据

大公司的波动性有多大？我们通过简化形式分析和校准练习来回答这个问题。首先，我们利用德国城市的时间和空间变化，并表明 i) 较高的集中度与更持久的当地商业周期相关，ii) 当地集中度格兰杰导致当地就业波动。从商业周期的角度来看，我们发现证据只支持粒度驱动的衰退。接下来，我们按照 Carvalho 和 Grassi（2019 年）的思路校准结构模型，发现大城市中更肥尾的生产力分布也关键取决于企业增长的更高概率。