Based on the background of the promotion tournament, there exist the differences between officials′ promotion expectations during their limited tenure. Those differences may cause the officials′ myopic behavior and thereby affect innovation outputs. However, limited existing literatures have studied institutional motivation of urban innovation from an officials′ promotion perspective. Also, they have not clarified clearly the specific influence mechanism of political institutions, including officials′ tenure on urban innovation. 

      Therefore, according to existing studies, for the sample period of 2004-2016, we utilize the panel data of 285 cities to examine how officials′ tenure affects urban innovation through economic growth targets, and further propose two new mechanism paths from the perspectives of land finance and environmental governance. The conclusions drawn by using the method of multivariate statistical regression analysis show that: (1) The municipal party secretaries′ tenures have a greater impact on urban innovation, relative to that of mayors, showing a significant inverted U-shaped relationship; (2) The municipal party secretaries′ turnovers significantly inhibit urban innovation; (3) The mechanism analysis indicates that the municipal party secretaries′ tenures affect urban innovation through three channels, including setting economic growth target, land finance and environmental governance. For example, with a higher economic growth target, the officials are more likely to adopt short-sighted expansion strategy to stimulate the economy, and then restrain urban innovation; (4) Heterogeneity test results show that the U-shaped characteristics of the municipal party secretaries′ tenures on urban innovation are still significant in regions with higher marketisation, in the eastern China or in the larger cities. 

     This study contributes to several strands as follows: (1) Our conclusions can enrich the empirical evidence for the theory of promotion incentives. The majority of existing literatures have focused on the influence of promotion tournament on economic growth, but rare literatures have discussed the influence of official tenure on innovation output. (2) We clarify clearly the mechanism influence of official tenure on urban innovation, and empirically examine the dynamic impacts of official tenure on urban innovation by three channels such as economic growth goals, land finance and environmental governance policies. (3) This paper helps better understand the impacts of administrative system on the high-quality transformation development. Early literatures have mainly focused on the influence of economic factors on urban innovation at the city level, but few literatures have studied the influence of political system, especially local officials on urban innovation at the medium level. Therefore, this study is a significant added to the literatures.

     This paper suggests that the government should reasonably arrange officials′ tenure, which not only ensures the stability and continuity of economic policies, but also avoids the collusion between officials and enterprises. The government should establish evaluation indicator system for official promotion to guide local governments setting moderate economic growth targets. Local governments should properly handle the relationship between ecological environment and economic development. Local governments should adopt diversified policies to promote urban innovation and economic development. Finally, the government should take measures according to local conditions, and combine better the "efficient market" and the "effective government" when promoting the reform of fiscal decentralization system.