管理者過度自信與盈餘管理

MANAGERIAL OVERCONFIDENCE AND EARNINGS MANAGEMENT

盈餘管理文獻多從代理成本或非理性投資者的角度進行分析，本研究以2006年第一季至2011年第四季台灣上市櫃公司為研究樣本，探討管理者心理認知偏誤－過度自信對盈餘管理的影響，並且加入GDP成長率作為解釋變數，探討總體經濟景氣是否影響盈餘管理，以及其效果是否會因管理者過度自信而有所差異。實證結果顯示，當以管理者連續四季增加持股來定義管理者為過度自信時，過度自信對盈餘管理程度有顯著的負向影響，表示過度自信管理者採取較低的盈餘管理程度，而且此效果來自於虛減盈餘的負向盈餘管理，過度自信對虛增盈餘的正向盈餘管理程度並無顯著影響，因此過度自信管理者提供較佳的盈餘品質。其次，管理者會根據總體經濟景氣變化調整盈餘管理，隨著GDP成長率的提高，管理者會提高正向、縮小負向盈餘管理之程度，而過度自信管理者於負向管理的調整幅度顯著低於理性管理者。

By using panel data of publicly traded Taiwan companies from 2006Q1 through 2011Q4, this study investigates the effect of managerial overconfidence on earnings management. Managers are defined as overconfident if they persistently increase their holdings of company stock. In addition, we analyze whether and how macroeconomic condition affects earnings management. We find that negative earnings management is significantly smaller in companies with overconfident managers, and positive earnings management is unaffected by managerial overconfidence. We also find that as GDP improves positive earnings management will become greater and negative earnings management will become smaller, respectively. This effect of economic condition on earnings management is weaker in companies with overconfident managers.