The Spatial Spillover Effect of Innovation Output in Urban Agglomeration and its Influencing Factors Analysis

To explore the collaborative innovation relationships within urban agglomerations and promote the sustainable development of non-first - and second-tier cities in China, empirical analysis was conducted from the perspective of innovation output. This study used the spatial seemingly unrelated regression (SUR) and the mixed panel model to empirically analyse the spillover effects of innovation output space in urban agglomerations, and considered the dependent variable spatial lag term in SUR. The results show that the SUR model designed in this study exhibited spatial lag data consistent with historical development patterns and trends in the data of China’s four major urban agglomerations. The mixed panel model calculation outcomes indicate that the construction of urban agglomerations, overall technological level, government financial support level, degree of openness to the outside world and differences in higher education have a significant positive impact on the spatial spillover of innovation. The estimated [Formula: see text] coefficients are 0.561, 0.816, 0.732, 0.472 and 0.357, respectively. However, differences in urban industrial structure have a negative impact on innovation output spillover effects, with an estimated [Formula: see text] coefficient of 0.316. The research results indicate that the spatial spillover effect of innovation can be enhanced by strengthening the construction of urban agglomerations, improving the technological level, increasing financial support, promoting opening up to the outside world and optimising the layout of higher education. At the same time, attention should be paid to the rational layout of the industrial structure to promote the coordinated development of the regional economy. The research results contribute to optimising policy design, strengthening regional planning and improving resource allocation efficiency, thereby promoting the enhancement of regional innovation capabilities and the sustainable development of cities.