As an important financial means for governments to improve the quality of economic development, government debt greatly affects the quality of local environmental governance. Based on a theoretical mechanism analysis that uses the pollutant emissions panel data and new caliber urban investment bond data of 273 cities in China, this paper empirically tests the impact of local government debt on urban emission reduction and the mechanism that drives this impact. We find that local government debt significantly promotes urban emissions reduction, and as urban pollution becomes more aggravated, this promoting effect has a dynamic path, first strengthening and then weakening. The role of local government debt in promoting urban emission reduction is characterized by both temporal and spatial heterogeneity. A mechanistic analysis shows that local government debt can promote urban emission reduction by promoting urban environmental innovation, with green invention patents demonstrating a stronger intermediary role than green utility model patents.

Purpose The purpose of this paper is to examine whether fiscal decentralization has impacts on city innovation level and to examine the moderating effects of the preference for government innovation in China. Design/methodology/approach Using a panel data of China’s 278 cities from 2003 to 2016, the authors first use fixed-effect model and quantile regression to analyze the impact of fiscal decentralization on city innovation level and the variations of impacts conditional on different innovation levels, followed by a mediating effect model to test the moderating effects of the preference for government innovation and its temporal and spatial heterogeneity. Findings The paper finds that fiscal decentralization significantly inhibited city innovation, and with the improvement of city innovation level, the inhibition demonstrated characteristics of “V” type variation. When the degree of fiscal decentralization is between 0.377 and 0.600, the inhibition of fiscal decentralization on city innovation level is the weakest. We further show that fiscal decentralization also inhibits the government's preference for innovation, reduces the proportion of fiscal expenditure on innovation and has a negative impact on city innovation. In addition, the influence of fiscal decentralization on city innovation present clear heterogeneity in space and in time. On one hand, the inhibition of fiscal decentralization on city innovation level in eastern China is significantly weaker than that in central and Western China; on the other hand, after the implementation of China’s innovation-driven development strategy in 2013, the negative impact of fiscal decentralization on city innovation disappeared. Research limitations/implications The research findings have certain policy implications. That is, in the process of decentralization reform, on the one hand, the central government should strengthen the supervision over the fiscal expenditure of local governments and ensure that the central government can play a leading role in the local development strategy, on the other hand, the central government should guard against the distortion of fiscal decentralization on local governments' fiscal expenditure behavior. In addition, the central government should also focus on the heterogeneity of the impacts of fiscal decentralization on cities under different strategic backgrounds and different levels of innovation. Originality/value This paper extends prior research by bringing the decentralization system reform into the study of city innovation system and analyzing its mechanism and its temporal and spatial heterogeneity.

China’s High-tech Industrial Development Zones (HTZ) are industrial agglomeration areas established by the local government to foster economic innovation. As springboards for cities to implement innovation-driven development strategies, HTZs have significant spillover and driving effects on urban ecological innovation. Based on panel data taken from 215 cities between 2003 and 2016, this paper empirically analyzes the impact of HTZ construction and its mechanisms as they pertain to urban ecological innovation. This analysis is framed by the double difference model and the intermediary effect model. It found that HTZ construction can effectively enhance urban ecological innovation, and formidably promote ecological innovation in central and eastern cities, as well as cities with superior scientific and educational resources. The intermediary mechanism analysis revealed that HTZs result in a policy depression effect, which may promote the agglomeration of urban innovation factors (including high-quality talents and investment), thereby bolstering urban ecological innovation. Moreover, HTZs’ investment agglomeration effect is primarily responsible for driving urban ecological innovation. Indeed, the HTZ construction may not only promote the local ecological innovation, but also have a significant spillover effect on the ecological innovation activities of other cities in the province.