上市公司盈利预测偏差与股价操纵

Management Earnings forecast Bias and hyping the Stock

行为金融理论中关于管理者过度自信的界定指标存在许多讨论,国内学者大多采用盈利预测偏差表征管理者过度自信。但是,由于管理者有可能以盈利预测作为信号传递给市场投资者,从而达到操纵股价的目的,因此采用上市公司盈利预测偏差可能并不能很好地度量管理者过度自信。本文使用A股2010年至2016年的数据,检验了用盈利预测偏差度量的管理者过度自信的合理性,及管理者是否通过发布高估盈利的业绩预告操纵股价。本文的研究结果发现,过度自信样本在业绩披露前的股票收益率显著低于其他公司,且披露有偏差预测的年份公司管理者会减持公司股票、公司经营情况还会显著变差。这些实证结果表明了盈利预测偏差并不能表征管理者过度自信,公司管理者通过披露高估盈利的业绩预告操纵股价。本文进一步研究发现,公司通过盈利预测偏差操纵股价主要是帮助管理者减持股票获利,且这种操纵行为能够被基金识别。

In behavioral finance theory, there are many discussions about the definition indicators of managerial overconfidence.Domestic scholars mostly use management earnings forecast bias to represent the managerial overconfidence. However, it is possible for managers to use earnings forecasts as a signal to market investors in order to achieve the purpose of manipulating stock prices. Therefore, the management earnings forecast bias of listed companies may not be a good measure of the managerial overconfidence. This article uses the data from 2010 to 2016 in China, tests the rationality of measurement of managerial overconfidence by the management earnings forecast bias, and whether managers hype the stock by publishing overestimate management earnings. The results of this study found that, the overconfidence sample had a significantly lower yield than other companies before the management earnings forecast was disclosed, managers of these companies reduced their holdings, and the operating conditions of the companies with the biased forecast were significantly worse. These empirical results show that the management earnings forecast bias does not represent the managerial overconfidence. The company’s managers can manipulate the stock prices by revealing overestimated earnings forecasts. This paper further shows that companies manipulate stock prices through earnings forecast deviation mainly to help managers reduce their stock holdings, and this manipulation can be identified by funds.