沪市A股上市公司盈利性变迁研究

Research on the Vicissitude of the Profitability of A-Shares in Shanghai Stock Exchange

利用 1993～ 2 0 0 2年度净资产收益率 ,对沪市A股上市公司盈利能力变迁进行实证分析 ,可以总结出盈利性变化的基本规律 :沪市A股整体盈利能力很大程度上由新上市公司支撑 ,且不断下降 ;各上市公司盈利能力分化现象随时间推移而越来越明显 ,上市时间越长的公司盈利能力越差 ;同一年份上市的公司 ,大多在上市后的第 2至 4年完成盈利能力的分化过程 ,因而上市后的 1～ 4年是考察公司管理层的经营管理能力、上市公司盈利能力的最佳时期。

To summarize the rules of the vicissitude of the profitability of A-shares in Shanghai Stock Exchange, the returns of equity (ROE) of the listed companies during the period of 1993-2002 are examined and analyzed. Three rules are revealed. First, to some degree, the profitability of A-shares relies on newly listed companies and declines continually. Second, the difference among the listed companies becomes more and more distinct, and the longer the listed time, the weaker the profitability. Finally, for those companies listed in the same year, the differentiation of their profitability will almost complete in the next four years, so these years is the best period to examine the manager's ability and/or the profitability of a listed company.