关键词: 沪港通, 深港通, 股票市场对外开放, 创新投入, 双重差分法

Abstract: Focusing on the benefits and returns brought by the opening-up of the stock market, this paper adopts the difference-in-difference method and the propensity score matching method to estimate the impact of the implementation of the Shanghai-Hong Kong Stock Connect and Shenzhen-Hong Kong Stock Connect on corporate innovation investment. The findings reveal that the listed companies selected as the targets of the Shanghai-Hong Kong Stock Connect and Shenzhen-Hong Kong Stock Connect show a higher level of innovation investment. Further research finds that the opening-up of the stock market to the outside world has improved the innovation investment of listed companies through three channels: easing corporate financing constraints, improving stock liquidity and increasing risk sharing. Heterogeneity results show that, non-state-owned enterprises that have become the targets of the Shanghai-Hong Kong Stock Connect and Shenzhen-Hong Kong Stock Connect increase their innovation investment more significantly. The proportion of corporate accounts receivable has dropped significantly, that is, the opening-up of the stock market to the outside world has improved the stability of the cash flow of listed companies, which may also be one of the reasons for increased investment in innovation.

Key words: Shanghai-Hong Kong Stock Connect, Shenzhen-Hong Kong Stock Connect, Stock Market Opening-up, Innovation Input, Difference-in-Differences