投资者是理性的吗?——基于ST公司交易特性和价值的分析

以1998年到2004年全部A股公司为样本,本研究系统考察了被特别处理(ST)公司的股票交易特性与估值。结果发现,当上市公司被实施ST以后,其股票交易显著偏离市场指数,呈个性化波动态势;在被实施ST期间,公司价值被显著低估。这一发现意味着投资者在投资ST股票时,总体是理性的,ST政策发挥了预期的警示作用。  

Should earnings thresholds be used as delisting criteria in stock market?

In Chinese stock market, firms reporting two consecutive annual losses are subject to special treatment (ST), with further losses causing the firms’ stocks to be suspended from trading or to be delisted. We argue that these earnings-based delisting requirements are misconstrued. Such policies drive financially healthy firms out of stock market, and induce listed firms to engage in rampant earnings manipulation in order to avoid delisting. The results carry important public policy implications for securities market regulation.  

虚设还是威慑：退市制度市场效应研究

通过建立动态博弈模型分析股市摘牌的作用机理,实证研究"ST预警—摘牌"退市体系的市场认可程度。结果发现,虽然退市预警制度在短期内能较好地向市场传达风险信号,但在中长期里给予了投资者投机炒作的空间,这有助于解释为何以往理论研究与市场观察结果相悖;即便我国股市摘牌强度相对较低,但市场能识别摘牌强度的信号并对其做出显著反应,摘牌起到了"杀鸡儆猴"的威慑作用。