Assessing the effect of urban digital infrastructure on green innovation: mechanism identification and spatial-temporal characteristics – Humanities and Social Sciences Communications

Digital infrastructure promotes urban green innovation

Digital infrastructure is a vital cornerstone of the digital economy’s long-term, stable growth, with significant enabling effects on both economy and society. It opens up new development paths and viable spaces for innovative activities, which will stimulate green innovation based on human, financial, and material paths.

First, digital infrastructure can influence the growth of urban green innovation through talent agglomeration. It can effectively break information, knowledge, industrial, and spatial boundaries and promote the convenient and efficient transmission of data and information in life. With its deep vertical penetration and remarkable information resource integration capability, it breaks barriers of knowledge and technology, enables knowledge dissemination and shares among different innovation subjects (Paunov and Rollo, 2016), improves urban informatization and recruits scientific and technological expertise. Talents are the creators and disseminators of advanced ideas and culture, and progress in science and technology requires advanced ideas to drive it, which ultimately requires talents to achieve it. The network clustering effect of digital infrastructure helps promote the establishment of knowledge networks that support urban green innovation with enough talent and knowledge.

Secondly, digital infrastructure can support green innovation through increasing R&D investment. Digital infrastructure offers more productive platforms and tools to encourage innovative R&D work and broadens access to R&D resources. Through digital platforms and open data resources, R&D institutions can access large-scale and diversified data, which helps them understand market demand and development trends, effectively avoiding the risk and waste of invested resources; meanwhile, digital technology combines technological innovation and business models, creates more market and commercialization opportunities. Digital infrastructure offers a platform for researchers to disseminate and apply their research results. Researchers and developers can translate innovative technological achievements into commercial products and services and realize economic value. Such commercialization opportunities stimulate increased investment in R&D and drive more profound green innovation.

Thirdly, digital infrastructure can support urban green innovation by upgrading industrial structures. Digital technologies can alter and empower traditional infrastructure and encourage the digital upgrading of traditional sectors effectively (Guo et al., 2023). It can also cause a close connection between the supply and demand sides, and bring out new industries and models. At the same time, emerging technologies and digital infrastructure can benefit from one another, and encourage digital technologies while facilitating cross-border industry integration. It hastens the demise of dormant industries, fosters the growth of new industries, and continuously optimizes the layout, structure, function, and development mode of industries, thus further influencing urban green innovation development.

Therefore, the hypothesis 1 is proposed:

H₁: Digital infrastructure can contribute to urban green innovation.

Regional heterogeneity in the green innovation effects of digital infrastructure

As the core carrier of regional economic development and an indispensable medium for building an ecological civilization, cities have the dual mission of stimulating innovation momentum and focusing on green development to improve the environment and the economy (Dong et al., 2023). Digital infrastructure can empower urban green innovation by enhancing fast and convenient information and knowledge flows through data elements and intelligent technologies. Considering the notable variations in resource endowments and policy environments of different cities, digital infrastructure may have various effects.

On the one hand, the internal resource endowments within cities, such as city size and human capital level, which show an important influence on developing digital infrastructure and promoting green innovation. Firstly, differences in city size. Cities of different sizes differ in economic level, industrial structure, and technological and financial development. Larger cities have the advantage of economic resources, human resources, and other factor endowments and attach more importance to green innovation, which may lead to more decisive in promoting green innovation. Secondly, disparities in human capital levels. Human capital-rich cities tend to have a more substantial knowledge and technology base for green innovation, a relatively more potent ability to absorb and utilize new digital technologies, more convenient interdisciplinary collaboration and knowledge sharing, and a more friendly innovation culture and entrepreneurial environment, which can better enhance green innovation.

On the other hand, the cities’ external policy environment like environmental regulations and financial subsidies (Hu et al., 2023a), can also influence the green innovation implications of digital infrastructure. First, environmental regulations vary. Regions with stronger environmental regulations usually adopt stricter environmental protection policies, which exert external policy pressure on enterprises and innovators and provide clear directions and standards, inspiring innovators to use digital infrastructure more actively to support urban green innovation, thus boosting city transformation towards green and sustainable growth. Secondly, the difference in financial subsidies. Financial subsidies provide external policy incentives such as financial support for innovation agents, reduce the costs and risks for enterprises to undertake innovation activities, and make green innovation feasible and attractive (Wei et al., 2023). It also promotes the spread and development of digital infrastructure, accelerates continuous technological upgrading and innovation, and pushes cities to achieve a higher level of green development.

Accordingly, research hypothesis 2 is proposed:

H₂: The contribution of digital infrastructure to advancing urban green innovation is heterogeneity, showing a stronger effect on cities with larger sizes, higher human capital, higher environmental regulations and higher financial subsidies.

Digital infrastructure has a spatial spillover effect on urban green innovation

Digital infrastructure is characterized by integration, intelligence, and development, which can not only empower local green innovation but also break the spatial and temporal boundaries of factor flow, promote the flow of resources, enhance exchanges and cooperation, optimize resource allocation and industrial spatial layout, achieve integration of resources, and develop other regions’ green innovation efficiently. Digital technology’s ongoing development and wide-ranging uses reduce the time and cost of knowledge learning, increase the speed of dissemination and diffusion of green knowledge and technology between regions, shorten the spatial and temporal distance of green innovation resources transferring between different regions (Forman and van Zeebroeck, 2019), enhance the breadth of association and depth of exchange of innovation activities between regions (Li et al., 2022; Li et al., 2023b), and enhance the transfer of green knowledge technologies to nearby locations, stimulate more cities to reinforce green innovation. In addition, digital infrastructure makes it possible for the movement of production elements including labor, money, and technology to overcome geographic constraints. It is beneficial to improve capital and labor productivity, foster transforming and upgrading industries, and accelerate green innovation industries development. Create a positive feedback loop of talent agglomeration and spread it to related industries to generate the positive spatial spillover effect. At the same time, developing digital infrastructure can play a good demonstration and warning effect, which is conducive to promoting healthy competition, exchange, and cooperation among regions, forming a cross-regional green innovation ecosystem. Through digital platforms and collaboration tools, innovation agents in different cities can cooperate more closely and efficiently, and the formation and expansion of this cooperation network enhance the scale effect, further supporting the spread of green innovation.

Therefore, research hypothesis 3 is suggested:

H₃: Digital infrastructure has a positive spillover effect and can promote green innovation capacity in nearby places.

Digital infrastructure has a threshold effect on urban green innovation

Information technology influences every part of society due to the maturity of digital infrastructure. It has accelerated industrial digitization, accumulated abundant data resources, and realized transmission, sharing, and aggregation with the digital platform to form a powerful network effect. Big data encourages collaboration and cross-border integration among various organization departments, enterprises, and industries. This causes the value chain to be optimized and reorganized, weakens the boundary of innovation activities, lowers the threshold and marginal cost of parity, and increases innovation income. Therefore, with the continual growth of digital infrastructure, its role in fostering urban green innovation will strengthen. Meanwhile, digital infrastructure itself will show the characteristics of marginal increase. Digital technology has an apparent self-growth effect due to iteration and updating, which can lead to greater technical assistance, a larger collaborative platform, and a more conducive atmosphere for urban green innovation. It provides new development space and opportunities, and forms the marginal increase of digital infrastructure’s effect on green innovation.

Accordingly, the study suggests the hypothesis 4:

H₄: Digital infrastructure has a threshold effect on urban green innovation, showing a nonlinear feature of increasing marginal effect.