Unveiling the hidden effects of multilevel administrative boundaries on human mobility

Multilevel administrative boundaries create various forms of political and institutional influences on human mobility. However, quantitative evidence for these influences are absent. We examine this using mobile phone data of 107.48 billion trips across 2844 administrative units in China, a typical case experiencing significant transitions in administrative system. An extended gravity model, incorporating these boundaries, achieved 92.75 % precision and 0.23 improvement in adjusted R-squared over the classic model. Results show second-level (municipal) administrative boundaries impact mobility 3.86 times more than first-level (provincial) administrative boundaries on average. Municipal boundaries exert stronger effects in developed areas, while provincial boundaries show relatively balanced effects across regions. Municipal boundaries are linked to fiscal revenue decentralization, while provincial boundaries relate more to fiscal expenditure. Administrative boundaries influence social differentiation in mobility, with a stronger effect on females and younger populations. These findings contribute to the development of more accurate transportation models and reasonable mobility-management policies.