企业的成本粘性被高估了吗?基于中国上市公司的实证研究

An Empirical Study on the Upward Estimation Bias in Cost Stickiness： Evidence from Chinese Listed Companies

现有对中国企业成本粘性的实证研究普遍使用上市公司财务数据。使用此类数据衡量的成本变动在反映真实成本性态的同时，还会受到管理层盈余操纵行为的影响。本文提出，现有研究由于忽略后者对披露成本变动的影响，所得到的成本粘性的估计很可能存在系统性偏差，特别是当企业面l临亏损时管理层往往采用“洗大澡”式的盈余管理，造成与业务量下降相对应的成本下降幅度减小，从而造成使用基于传统模型估计出的成本粘性参数高于真实的成本粘性。本文在理论分析的基础上对估计成本粘性的经验模型进行了改进，使用1994-2008年间中国上市公司样本对上述假设进行了实证检验。我们发现，在考虑了“洗大澡”因素的影响后，估计得出的“管理费用”的粘性参数下降了超过三分之二，而“销售费用”的粘性则基本消失。其他稳健性检验结果也支持以上结论。综合而言，本文的分析表明，忽略盈余管理的因素的确造成了对中国上市公司成本粘性的普遍严重高估。

Prior studies on sticky cost behavior routinely use data from companies＇ finan- cial statements to estimate the cost stickiness parameter. This method is likely to produce systematic upward bias in cost stickiness due to managers＇ incentive in engaging in earnings management in the form of ＂big bath＂ when a sales decline is accompanied by accounting los- ses. We empirically test this hypothesis using data from Chinese listed companies during1994--2008 and find evidence of significant upward bias in the estimated stickiness for both Administrative Expenses and Selling Expenses. The results indicate that estimating cost stickiness based on financial statement data while ignoring managers＇ financial reporting in- centives leads to grossly overestimated cost stickiness.