Abstract:    This paper takes the A-share listed companies of China from 2010 to 2019 as a sample, trying to investigate the impact and mechanism of corporate social responsibility (CSR) on corporate innovation. The empirical study finds that CSR has a significant positive impact on innovation input, innovation output and innovation efficiency. Further mechanism analysis shows that corporate social responsibility promotes enterprise innovation by alleviating financing constraints, reducing financial risks and inhibiting principal-agent problems. Heterogeneity analysis shows that compared with substantive innovation, CSR has a more significant impact on strategic innovation, and the positive correlation between CSR and corporate innovation is more significant in state-owned enterprises and enterprises in non-sensitive socially responsible industries.Our contribution is as follows: First, it enriches extant literature on the influencing factors of corporate innovation and provides a new perspective for the research on the economic consequences of corporate social responsibility. Second, it examines the impact of corporate social responsibility on corporate innovation, including innovation input, innovation output and innovation efficiency, with a more comprehensive and in-depth perspective. In fact, although China currently ranks 14th in the Global Innovation Index (GII), it still has weaknesses in all pillars of the GII except knowledge and technology output. Therefore, a comprehensive investigation of the factors affecting corporate innovation capabilities can provide new ideas for the current dilemma of innovation in China. Third, this paper finds that the positive impact of CSR on corporate innovation is weaker for enterprises in sensitive socially responsible industries and non-state-owned enterprises, which indicates that the enterprise innovation incentives should not be the one-size-fits-all policy, the effect of differential incentive policies based on different nature of enterprises may be more significant.This paper also provides some important implications. First, the existing research has conducted a lot of research on how to improve the innovation ability of enterprises, but it ignores the essential problem that the enterprise itself is a "contract " integrating many stakeholders. Only by unifying the interests of stakeholders can the problem of insufficient innovation be solved in essence, and corporate social responsibility can play the role of such an invisible contract. Therefore, on the one hand, the government can introduce relevant policies to encourage enterprises to attach importance to social responsibility. On the other hand, enterprises can establish a corporate social responsibility strategy serving innovation, so as to realize a win-win situation. Second, corporate social responsibility has a lagging effect on the improvement of innovation capability of enterprises, so the government can introduce corresponding rewards and punishment mechanisms to guide enterprise managers to take social responsibility. Third, this paper finds that the impact of social responsibility on corporate innovation varies with the nature of corporate property rights and the CSR sensitivity of the industry in which the firm is located, indicating that the incentive measures for corporate innovation should adopt a differentiated strategy. For example, for state-owned enterprises, the factors that hinder innovation of such enterprises are more likely to be the opportunistic behavior of agents and the "internal controller" problem rather than the financing constraints. Therefore, the implementation of reasonable incentive mechanism to suppress the occurrence of internal governance problems and the establishment of social responsibility system to play the supervisory role of other stakeholders is more conducive to promoting the innovation of state-owned enterprises.

Key words: social responsibility, corporate innovation, financing constraint, financial risk, principal-agent problem