Agglomerative Forces and Cluster Shapes
建立模型解释相似企业如何形成空间集群，揭示集聚力通过局部连接和交互成本塑造集群形状与大小，并用硅谷的技术与劳动力流动数据验证了模型假设。
We model spatial clusters of similar firms. Our model highlights how agglomerative forces lead to localized, individual connections among firms, while interaction costs generate a defined distance over which attraction forces operate. Overlapping firm interactions yield agglomeration clusters that are much larger than the underlying agglomerative forces themselves. Empirically, we demonstrate that our model’s assumptions are present in the structure of technology and labor flows within Silicon Valley. Our model further identifies how the lengths over which agglomerative forces operate influence the shapes and sizes of industrial clusters; we confirm these predictions using variations across patent technology clusters.