考量到經理人並非全然理性的狀況,本論文因此納入經理人「過度自信」(overconfidence)此一被廣泛採用的行為因素,以探討經理人之家族企業特性與過度自信傾向對其舉債決策的影響。本文以2001年至2007年間台灣上市櫃公司為樣本,並考量到內生性問題,而利用三階段最小平方法檢測:(1)家族企業與非家族企業經理人所選擇的負債水準是否有差異;(2)過度自信是否為影響負債水準之因子;(3)探討家族企業之經理人其家族企業特性是否會制約過度自信對其舉債行為的影響力;(4)本研究進一步將家族企業經理人分成由家族成員擔任與非家族成員擔任者,以釐清同樣在具有過度自信傾向的情況下,家族企業與非家族企業經理人舉債行為的差異是來自於家族企業的何種類型經理人。 實證結果發現:(1)家族企業經理人相對於非家族企業者會選擇較高的負債水準,表示家族企業經理人傾向採用高舉債來維持控制權以及鞏固控制私有利益(private benefits of control);(2)過度自信經理人相較於非過度自信者會選擇較高的負債水準,表示過度自信的經理人會由於高估其公司證券的價值,而認為該證券的價值被外部市場低估,融資成本過高,使過度自信的經理人在面臨資金需求時,會偏好發行價值被低估程度較小的債券而非權益;(3)相較於非家族企業具過度自信傾向的經理人,家族企業經理人若具過度自信傾向,在家族企業「風險趨避」特性的壓制下,反而會選擇較低的負債水準;(4)在同樣具有過度自信傾向的情況下,家族企業與非家族企業經理人舉債行為的差異是來自於家族企業具過度自信的家族成員經理人。 Considering the fact that managers cannot be totally rational when it comes to decision-making, this paper incorporates one of the commonly used behavioral factors, overconfidence, and examines how family business characteristics and overconfidence affect their financial leverage. This research sample contains Taiwanese listed and OTC companies, and uses three stages least squares method to solve the endogeneity problem. This paper investigates whether financial leverage of family businesses is different from that of non-family businesses; whether managers’ overconfidence has a role to play in their capital structure decision; and whether the unique characteristics of family businesses would suppress the influence of managers’ overconfidence on financial leverage. Moreover, this research divides managers of family business into two groups, one is family CEOs and the other is non-family CEOs in order to find out the source of the difference of financial leverage between family and non-family businesses under the condition that managers are overconfident. The results support the hypothesis that family business managers tend to use more debt for maintaining the control right to the company and entrenching their private benefits of control. Second, overconfident managers prefer higher financial leverage than non-overconfident managers. Moreover, compared to overconfident non-family business managers, overconfident family business managers would use less debt under the suppression of family business’ “risk-averse” characteristics. Finally, under the condition that managers are overconfident, we find that the difference of financial leverage between family and non-family business comes from family business’ family CEO.