股权激励存在持续性的激励效应吗？--基于倾向得分匹配法的实证分析

摘要

为克服样本选择偏误，本文采用倾向得分匹配法，在六年的时间框架内检验了股权激励效应的持续性问题。研究发现：整体而言，激励组的ROE和Tobin’s Q值均显著高于控制组，说明股权激励能有效地提高企业的财务绩效和市场价值；激励组的ROE在股权激励计划实施后的三年时间里均显著高于控制组，三年之后逐渐与控制组无显著差异，表明股权激励对企业财务绩效的提升作用能持续三年时间；激励组的Tobin’s Q值在实施的第一年与控制组无显著差异，但在随后的四年时间里均显著高于控制组，表明股权激励对企业市场价值存在长达四年的持续提升作用，但存在为期一年的时滞效应。%In order to address“sample-selection bias”, we employ propensity score matching method to examine the du-ration of equity incentive effects in a time frame of six years.The results are as follows: First, as a whole, the ROE and Tobin’s Q of the incentive group are significantly higher than those of the controlled samples, which means equity incentive can effectively improve corporates’financial performance and market value.Second, The ROE of incentive group is significantly higher than that of the controlled samples within 3 years after the implementation of equity incentive, but gradually shows no difference after the third year, which indicates that equity incentive’s promotion on financial performance can last for three years.Third, Tobin’s Q of incentive group is indifferent from that of the controlled group in the first year of implementation, however, during the next four years, it is significantly higher than that of the controlled samples, which means equity incentive exerts a persistent promotion on corporates’market value for four years with one-year-time-lag effect.