股价高估与商誉减值风险

Overvaluation and Goodwill Impairment

近年来,上市公司的商誉减值风险引起监管层和学术界极大的关注。文章基于2007-2017年我国上市公司的并购样本,发现公司在股价高估时期实施的并购在未来面临更高的商誉减值风险。微观经济机制分析表明,股价高估导致公司的并购数量和规模显著上升,且管理层在股价高估时期往往支付更高的溢价,从而产生巨额并购商誉;此外,公司在股价高估时期往往投资过度,引起并购投资效率下降,导致并购的协同效应收益低于并购商誉,从而产生商誉减值风险。文章揭示了股价高估往往导致公司做出盲目的并购决策,进而损害实体经济。文章的研究对于防范商誉减值风险具有重要的指导意义。

Based on the sample of mergers and acquisitions of A-share listed companies in China from 2004 to 2017,this paper studies the effect of the overvaluation of the stock price on goodwill impairment.We construct the overvaluation variable by following the decomposition of the market to book ratio in RhodesKrof,et al.(2005).We find that when the stock price is overvalued,the firm will face higher goodwill impairment in the future.Furthermore,we study the underlying micro-level mechanism between overvaluation and goodwill impairment.First,the firm tends to make more acquisitions during the overvaluation period of the stock price.Overvaluation leads to higher equity value,hence the firm can use overvalued stock to make more mergers and acquisitions.Second,managers tend to pay acquisition premium during the overvaluation period.It is beneficial for the firm as long as the premium is lower than the overvalued market value.Moreover,overvaluation sends the wrong signal to managers,which makes managers too optimistic about the prospects of acquisitions.Managers are willing to pay a higher premium in the optimistic mood.Finally,overvaluation leads to overinvestment,and hence reduces the acquisition efficiency.Overvaluation usually leads to higher agency costs.Mergers and acquisitions during the overvaluation period are often related to capital market operation,controlling shareholder tunneling and earnings management,which lead to managers’irrational acquisition decisions which will damage the firm’s value.Therefore,the gains of the synergistic effect are lower than the overpaid premium during the overvaluation period,which leads to higher goodwill impairment in the future.Theoretically,the contributions of this paper are as follows:First,it reveals that stock mispricing in the capital market has an impact on the real economy.The evidence in this paper shows that overvaluation usually leads to irrational acquisition decisions,thus damaging the real economy.Second,it expands the research on the goodwill impairment.There are few cases of goodwill impairment in China and previous researches mainly focus on the case study on goodwill impairment of the representative firms.This paper conducts an empirical study on goodwill impairment of all the A-share listed companies in China,and finds that the overvaluation of the stock price leads to higher goodwill impairment.In addition,this paper has a strong practical significance.It shows that the firm usually makes irrational mergers and acquisitions and pay high acquisition premium when the stock price is overvalued,which leads to the goodwill impairment in the future and damages the company’s operating and management.We present the corresponding policy recommendations.Regulators should strictly review the acquisition schemes with high valuation and premium,especially during the overvaluation period of the stock price.