激励还是挤压？——新股上市对已上市公司创新活动的影响

王明威 李 朵 罗 婷¹

摘要 本文发现新股上市所产生的进入威胁能够促进已上市公司进行创新。我们借助2008年和2012年两次IPO暂停事件捕捉不同行业企业所面对的进入威胁差异，构造双重差分模型进行研究。结果表明，在IPO暂停期间，面临高进入威胁的已上市公司显著增加了研发投入。机制分析表明，当企业创新倾向较高或者管理层短视现象严重时，本文的主要发现更为显著。这说明新股上市所产生的进入威胁可以激励企业通过创新获取先发优势，抑制管理层短视行为，进而促进企业创新。进一步分析表明，本文的主要发现在融资约束较低的企业中更为显著，以专利数量度量的企业创新产出也显著增加。本文结果表明了新股上市能够对已上市公司创新活动产生积极作用，为当前“支持优质企业上市”的政策导向如何提高上市公司质量、助力高质量发展提供了新的证据。

关键词 IPO 创新 进入威胁 IPO暂停

Promoting or Constraining? The Effect of IPO on Incumbent Firms' Innovation

MINGWEI WANG DUO LI TING LUO

Abstract This paper provides evidence that the entry threat generated by IPO can faci-litate innovation of incumbent firms. We use 2008 and 2012 IPO suspensions to capture the differences in entry threat faced by incumbent firms and employ DID model for our research. We find that listed firms facing high entry threats significantly increase their R&D investment during IPO suspensions. Mechanism analysis shows that this effect is more significant for the incumbent firms with higher innovation propensity or managerial myopia, suggesting that the entry threat from IPO can incentivize incumbent firms to obtain a first-mover advantage through innovation and discourage managerial myopia, thereby promoting firm innovation. Further-more, this effect is more significant for firms with lower financing constraints. Additionally, the final innovation output of the incumbent firms, measured by the number of patents, also significantly increases. The results suggest that IPO can promote the innovation of incumbent firms, and provide new evidence on how the policy orientation of “ supporting quality compa-nies to go public” can improve the quality of listed companies and contribute to high-quality development.

Key words IPO;Innovation;Entry Threat;IPO Suspension