中文摘要：

上市公司过度投资问题是研究的热点问题,一般研究将过度投资归结于代理问题和制度环境。不同于现有研究,本文从市场竞争动态性的角度研究过度投资,考虑到过度投资战略性特点：在激烈的市场竞争中,通过过度投资实现战略性的率先进入,形成先发优势,这也可能是上市公司过度投资的目的。利用中国上市公司的经验证据,研究发现,市场竞争的确会触发公司的过度投资行为,竞争和公司的过度投资水平是正相关的。存在竞争的情况下,市场竞争对过度投资的影响依赖于公司规模的大小：当公司的总资产自然对数大于19.555时,市场竞争才会刺激公司过度投资,反之,则降低过度投资。最后,我们发现不同的竞争强度的行业中,市场竞争对公司的过度投资影响是不同的。竞争激烈的行业中,竞争压力促使公司过度投资;竞争不激烈的行业,竞争压力较小的公司会主动过度投资;竞争中度的行业,竞争对公司过度投资没有显著影响。

英文摘要：

The overinvestment problem of listed companies is hot topic for researchers. Literatures attribute this problem to agency conflict and institutional environment. Unlike existing papers,this paper studies overinvestment by the perspective of competition change,considering the strategic feature of overinvestment. In competition,companies would like trigger overinvesting to entry firstly,to get first over advantage. This is also a reason for overinvesting. By using empirical evidence,we find the change in market competition would trigger overinvestment. Under the condition of competition becoming heavier,overinvestment can be affected by corporate size but upon the scale of assets. When corporate asset is larger than 19. 555,a shaper competition will cause overinvestment,vice versa. At last,we find change in competition affecting overinvestment depends on the industry situation. In a highly competing industry,a shaper competition would cause overinvestment; companies in low competition would trigger overinvesting actively; however,competition does not affect corporate overinvestment in median content.