Firm Sorting and Agglomeration
研究了异质性企业在不同城市间的选址如何影响城市规模分布和全要素生产率，发现大城市的效率优势近半来自企业分类，并评估了地方补贴政策的总体福利效应。
To account for the uneven distribution of economic activity in space, I propose a theory of the location choices of heterogeneous firms in a variety of sectors across cities. In equilibrium, the distribution of city sizes and the sorting patterns of firms are uniquely determined and affect aggregate TFP and welfare. I estimate the model using French firm-level data and find that nearly half of the productivity advantage of large cities is due to firm sorting, the rest coming from agglomeration economies. I quantify the general equilibrium effects of place-based policies: policies that subsidize smaller cities have negative aggregate effects.