Abstract
The explosive growth of patents in China has sparked widespread discussion, highlighting the inadequacy of merely analyzing innovation quantity to fully understand the underlying causes and consequences of genuine innovation capabilities. By introducing novel indicators for high-quality and low-quality innovations, this paper pioneers research relating to the structural factors behind the surge and quality disparity in Chinese patents. Empirical findings at the city level reveal that R&D cooperation and citation spillover both enhance a city's innovation quality, through different focal points. R&D cooperation can promote high-quality innovation within a certain range, thus contributing to a city's innovation quality. In contrast, the quality-enhancing effect of citation spillovers mainly results from the reduction in the proportion of low-quality innovation, described herein as the innovation bubble. The expansion of these bubbles, though associated with the rapid increase in innovation quantity, does not contribute to genuine innovation capabilities, creating an illusion of false innovation prosperity. Threshold regressions suggest that, despite their distinct roles, R&D cooperation and citation spillovers can complement each other. Additionally, heterogeneity analysis indicates that cooperation between cities with similar innovation capacities is more effective, fostering high-quality innovation and mitigating innovation bubbles, especially within a 450-900 km range. Beyond this distance, citation spillover becomes the more efficient approach to acquiring innovation knowledge, particularly in cities characterized by low-quality innovation.