Re-examination of urban innovation and its evolution in China: technological complexity and diversity as new perspectives

This study employs a non-linear iteration methodology to establish a set of indicators, namely technological complexity and innovation complexity, respectively for evaluating patent quality and the cities’ innovation competitiveness. Using Chinese invention patent application data spanning from 2003 to 2020 as a case study, we reassess the innovation competitiveness in Chinese prefecture-level cities and investigate the spatiotemporal evolution of city innovation from the perspectives of technological diversity and technological complexity. Results show: (1) During the study period, overall technological innovation in Chinese cities increased. However, notable heterogeneity was observed among cities in different urban clusters. (2) Technological diversity, indicating innovation breadth, proves less effective than innovation complexity, typically associated with innovation depth, when assessing the cities’ innovation competitiveness, especially for advanced cities. (3) Increased technological innovation in Chinese cities was associated with greater technological diversity and, more importantly, technological complexity enhancement. Nevertheless, noteworthy heterogeneity in technological innovation trajectories existed among cities: Innovation-advanced cities progressively shifted their focus from technological diversity to technological fields characterised by higher complexity, demonstrating a ‘narrow and deep’ tendency. In contrast, innovation-lagging cities tended to focus on technological diversity in fields with lower technological complexity, that is, emphasising innovation breadth rather than depth. List of Abbreviations: TC: Technological Complexity, TD: Technological Diversity, IC: Innovation Complexity, RPA: Relative Patent Advantage.