The empowerment-redundancy effects: How logistics infrastructure shapes urban logistics efficiency in China

Based on panel data from 284 prefecture-level cities in China from 2012 to 2022, this study measures urban logistics efficiency using a three-stage super-efficiency SBM-DEA model considering undesirable outputs, and empirically examines the impact and underlying mechanisms of urban logistics infrastructure on logistics efficiency. The research finds that: (1) The impact exhibits a significant U-shaped nonlinear characteristic, i.e., initially inhibiting and subsequently promoting, which remains valid after some robustness checks. (2) Eastern cities with high administrative level have crossed the inflection point of U-shaped curve, entering a dividend period of efficiency improvement. (3) The nearest neighbor distance of logistics network acting as a crucial spatial transmission channel has been verified. Specifically, shortening the nearest neighbor distance through urban infrastructure is a key driver for translating infrastructure layout into operational performance. (4) The development level of the digital economy plays a significant ‘empowering and enhancing’ moderator, effectively mitigating the congestion effect in the initial stage and strengthening the network effect in the mature stage, thereby making the U-shaped curve steeper. (5) The unleashing of infrastructure effectiveness exhibits threshold characteristics based on urban population size and temporal evolution. Finally, policy implications are proposed for promoting the high-quality development of China's logistics industry.