Localized economic spillovers of national logistics hubs: Micro-spatial causal evidence from China

National logistics hubs are central to China's transport infrastructure strategy, yet micro-spatial evidence on their local economic effects remains limited. This study examines the localized economic spillovers induced by National Logistics Hub Layout and Construction Plan policy, covering 151 national logistics hubs. To identify causal impacts, we combine high-resolution nighttime light (NTL) data with a continuous treatment difference-in-differences (DID) framework. The results show that logistics hubs generate significant positive spillover effects on surrounding economic activity and dynamic analysis indicates that these effects are cumulative rather than immediate. These findings are confirmed by extensive robustness and identification tests. Heterogeneity analyses reveal three key patterns. First, spillovers are stronger in central and western China, particularly northwest of the Hu Line, indicating greater marginal responses around hubs located in relatively less-developed areas. Second, land port, land border port, trade-service, and production-service hubs generate stronger local spillovers, suggesting that hubs more closely linked to industrial and commercial activities yield greater local economic benefits. Third, the estimated spillover effects are positive across hubs of all sizes, while among organizational forms a significant effect is found only for single-city hubs. These findings provide micro-spatial causal evidence on economic spillovers of logistics infrastructure.