Placebo test.

In the context of the digital economy, digital government construction is increasingly regarded as a vital approach to enhancing urban innovation governance. This study uses panel data from 292 prefecture-level and above cities in China spanning 2012–2023 and adopts a difference-in-differences (DID) model centered around the 2017 e-government pilot policy to systematically evaluate the impact of digital government on intra-city collaborative innovation. The findings reveal that: (1) the e-government policy significantly increased the frequency and scale of patent collaborations within cities, indicating its positive effect in stimulating multi-actor cooperation, optimizing factor allocation, and facilitating knowledge sharing; (2) mechanism analysis shows that digital government enhances fiscal efficiency and administrative transparency, strengthens targeted support for science and education sectors, and promotes the spatial agglomeration of innovation resources toward urban cores, thereby reducing collaboration costs and improving the efficiency of innovation networks; (3) heterogeneity analysis indicates that the policy effect is more pronounced in highly market-oriented regions and non-provincial capital cities, reflecting differences in institutional adaptability and resource-driven incentives. The study provides micro-level empirical evidence for understanding the collaborative innovation effects of digital government and offers theoretical insights for regional governance and policy design.