Abstract:     Regional innovation is not only affected by economic, social and natural factors, but also by government behavior and various institutions. In order to explore the impact and action mechanism of the supervision through inspection system on regional innovation, a multi-temporal double-difference model is constructed to test the 31 provincial-level regions in China from 2007 to 2020 selected as the research object, based on the quasi-natural experiment of inspection by the Central Commission for Discipline Inspection (CCDI). The study found that supervision through inspection has a significant promotion effect on regional innovation, and it also has a cross-period heterogeneity effect, but the long-term effect is better than the short-term effect, and the conclusion still holds after a series of robustness tests. The study on the action mechanism found that R&D investment has a masking effect between supervision through inspection and regional innovation, and that supervision through inspection reduces the quantity of R&D investment and improves the quality of R&D investment, and the quantity of R&D investment is increased. Moreover, through effective external supervision, the utilization efficiency of R&D investment is improved, thus promoting the improvement of the regional innovation level. The impact of supervision through inspection on regional innovation is regionally heterogeneous, and it is significant for the western region, but not significant for the central and eastern regions. The above conclusions have enriched the research system on the macroeconomic consequences of supervision through inspection and the factors influencing regional innovation, and they will provide reliable theoretical references and empirical evidence for strengthening the Communist Party of China (CPC)′s leadership and accelerating its entry into the forefront of innovative countries.

Key words: supervision through inspection, regional innovation, R&D investment, masking effect