Dual geographical and institutional boundary effects on intercity disparity in public services

Regions are inherently embedded by dual geographical and institutional boundaries that co-produce intercity disparity in public services; however, their separate effects and dynamic responses remain unclear. Using a city-dyad sample from China and operationalising boundaries via spatial adjacency and provincial affiliation, this paper isolates the independent effects of geographical and institutional boundaries and leverages urban agglomeration policies to identify the effects of boundary elimination. Results suggest that the dual boundaries reinforce the intercity disparities, while elimination efforts reduce disparities primarily only by dismantling institutional boundaries rather than geographical boundaries. This asymmetry stems from core–non-core dyadic city structures.