股票投机、信息发现与权益成本——对股权融资偏好的再讨论

Stock Speculation,Information Discovery and Cost of Equity:A Further Discussion on Equity Financing Preference

我国股市的过度投机与上市公司的股权融资偏好存在着内在的关联。本文以2006-2013年我国沪深A股主板市场上市公司为样本,研究了股票投机交易对权益成本的影响,以及信息发现机制在其中发挥的调节作用。结果表明,在控制了内生性和样本选择偏误之后,市场投机和个股投机都能够显著地降低权益成本;对于盈余预期更高的"好公司",投机交易对权益成本的影响更弱,支持了信息发现的"替代效应"假说。进一步的分析发现,再融资公司的权益成本与控制组相比显著更低,与上年相比也存在着明显的下降,成本偏低确实是股权融资偏好的重要原因。本文的研究充实了中国实践背景下的资本结构理论的相关成果,同时为推进资本市场健康发展、抑制市场非理性行为提供了证据支持。

There exists an internal relationship between the excessive speculation of Chinese stock market and the equity financing preference of listed companies. Using data of Shanghai and Shenzhen A-share stock on main board of listed companies from 2006 to 2013, this paper studies the impact of stock speculation on the cost of equity, as well as the mediating role of information discovery mechanism. Results show that, after controlling for endogeneity and sample selection bias, market speculation and stock speculation can significantly reduce the cost of equity. For ＂good firms＂ with higher earning expectation, the impact of speculative trading on the cost of equity is weaker, which supports the ＂substitution effect＂ hypothesis of information discovery. Further analysis reveals that, the cost of equity in refinancing companies is lower compared to the control group and declines significantly compared to the previous year, which indicating that low cost is indeed an important reason for equity financing preference. This research enriches the study of capital structure in Chinese context, also provides support for the development of capital market and regulation of irrational behavior.