中文摘要：

利用2009 2014年我国深市484家上市公司数据构建面板数据,在修正内生性的基础上,对50岁以上年长员工对企业绩效的影响进行实证研究。结果表明,年长员工对企业劳动生产率、劳动成本及净收益均存在负面影响,年长员工生产效能普遍不高,出现过早贬值。进一步分析显示,不同类型的企业中年长员工对企业绩效的影响存在一定差异：与制造业相比,非制造业中年长员工会带来更积极的影响;劳动密集型企业中年长员工对劳动生产率的负向影响、年轻员工对劳动生产率的正向影响作用较为显著。

英文摘要：

Using 484 public companies of SZSE as research samples, constructing panel data in 2009-2014, this study carries on an empirical analysis of the impact of older workers （elder than 50） on enterprise performance. Results show older workers have negative effect on company productivity, cost and profit respectively. Older workers＇ productive efficiency is generally not high, appearing premature devaluation. Further analysis shows that older workers＇ productive efficiency is different in different types of enterprises. Older workers have a relative positive influence on non-manufacturing industry. In labor-intensive industry, older workers have negative effect on productivity whereas younger workers have positive effect on productivity. In innovative industry, older workers raise the cost rather than promote the productivity.