Matching and Agglomeration: Theory and Evidence From Japanese Firm‐to‐Firm Trade
利用日本企业间贸易面板数据，发现企业因供应商破产而重新匹配的速度随替代供应商地理密度增加而提高；构建一般均衡模型揭示厚市场外部性产生的集聚外部性影响区域生产与福利，估计其对实际工资的弹性约为0.02。
This paper shows that matching frictions and a thick market externality in firm‐to‐firm trade shape the agglomeration of economic activity. Using panel data of firm‐to‐firm trade in Japan, I demonstrate that firms gradually match with alternative suppliers following an unanticipated supplier bankruptcy, and that the rate of rematching increases in the geographic density of alternative suppliers. Motivated by these empirical findings, I develop a general equilibrium model of firm‐to‐firm matching in input trade across space. The model reveals that the thick market externality gives rise to an agglomeration externality affecting regional production and welfare. Using the calibrated model to the reduced‐form patterns of firm‐to‐firm matching, I estimate that the elasticity of a region's real wage with respect to population density due to the thick market externality is approximately 0.02. This finding highlights the substantial impact of the thick market externality on the overall agglomeration benefit.