中文摘要：

利用上市公司的经验数据,实证研究了不确定性对上市公司投资行为的影响。研究发现：不确定性会降低公司的投资支出水平,而且公司层面的不确定性对公司投资影响要比市场环境的不确定性大;不确定性也会导致公司出现投资不足,但是公司层面的不确定性对投资不足的影响要比市场环境的不确定影响小。公司的竞争优势会缓解公司的投资不足,也会提高公司的投资水平。当公司处于行业中的竞争优势时,公司的投资水平明显要高。竞争优势能够缓解不确定性导致的投资不足程度。

英文摘要：

By using empirical data of listed companies, this paper considers uncertainty impact on corporate investment. The results show that uncertainty will cause corporate less investment quantity. The uncertainty of corporate can make bigger in- fluence rather than uncertainty of market competition. Uncertainty also cause corporate underinvestment, but the uncertainty of corporate effect is smaller than those of market competition. Besides, the dominant companies have a slighter underinvest- ment problem than others.