Digital technology has brought an end to the era where enterprises pursued innovation alone. Digital collaborative innovation, an innovative activity centered on digital innovation and conducted through multi-agent collaboration, is the result of the integration of digital innovation and collaborative innovation. Based on multi-agent collaboration, enterprises can easily break through technological barriers, expand their innovation networks, and unleash the vitality of innovation factors. A favorable intellectual property environment is an important factor in promoting cross-organizational collaborative innovation. Existing research has treated the construction of intellectual property demonstration cities as a quasi-natural experiment, discussing its impact on innovation, collaborative innovation, or digital innovation separately. However, how does the impact of intellectual property demonstration cities affect enterprise digital collaborative innovation, which centers on digital innovation and adopts the form of collaborative innovation? This topic has rarely been discussed in existing literature. With the accelerated penetration of digital technology in product collaborative innovation and industrial chain collaborative innovation, digital technology innovation consortia have become increasingly important; revealing the conditional mechanisms through which intellectual property demonstration cities trigger enterprise digital collaborative innovation holds theoretical value and practical significance.

Based on data from A-share listed companies from 2011 to 2023, this paper uses the construction of intellectual property demonstration cities as a quasi-natural experiment, characterizes digital collaborative innovation using jointly authorized digital patents, and examines the effects and mechanisms of intellectual property demonstration cities on digital collaborative innovation. The research finds that the construction of intellectual property demonstration cities has promoted an average increase of 22% in the rate of digital collaborative innovation among enterprises, indicating that public policies on intellectual property rights help to solve the property rights challenges of cross-organizational digital innovation and open up the channel for enterprises to integrate digital and physical innovation. Heterogeneity tests reveal that the impact of intellectual property demonstration cities on digital collaborative innovation only exists in the local creation effect, with no significant spatial spillover; enterprises with weak digital innovation foundations, those experiencing initial growth stages, and private "weak" enterprises are more likely to leverage public policies on intellectual property rights to gain the "wings" of digital-creative collaboration. In terms of mechanisms, enhancing multi-agent relationship connections, promoting the diffusion of basic research, and strengthening intellectual property enforcement are all important mechanisms through which intellectual property demonstration cities promote digital collaborative innovation among enterprises.

The potential academic contributions of this paper lie in the following aspects: Firstly, from a research perspective, this paper is an early empirical literature that examines the impact of intellectual property policies on enterprise digital collaborative innovation from the micro perspective of the interactive integration of digital innovation and collaborative innovation. Secondly, in terms of empirical strategy, this paper employs a multi-period difference-in-differences model to identify the causal relationship between intellectual property demonstration policies and enterprise digital collaborative innovation, providing incremental evidence for how to build a digital innovation consortium. Thirdly, in terms of mechanism analysis, this paper clarifies the theoretical mechanism through which the construction of intellectual property demonstration cities promotes enterprise digital collaborative innovation from three aspects: enhancing multi-agent relationship connections, promoting the diffusion of basic research, and strengthening intellectual property law enforcement. This provides theoretical guidance and practical insights for improving the intellectual property system, strengthening product collaborative innovation and building a digital innovation consortium.