本研究探討2004年至2015年間43家美國產險公司，CEO與Chairman過度自信及雙元性對於公司經營績效之影響。研究發現以股票淨購買(OCNETB)作為過度自信衡量方法時，CEO與Chairman之過度自信對於公司ROA與ROE影響都不具顯著性；以持有選擇權(OC67)作為過度自信衡量方法時，發現僅有CEO之過度自信對於下一期股東權益報酬率為顯著正相關。公司是否採用雙元性對於公司經營績效無顯著影響。董事會成員平均年齡與公司ROA與ROE呈顯著負相關；財務專家佔審計委員會之比例與公司ROE呈顯著正相關。控制變數發現地區集中度與公司經營績效呈現顯著負相關，而長尾險種保費佔率和公司規模與公司經營績效呈顯著正相關。 本文亦考量金融風暴前後對於公司經營績效之影響，研究結果發現以持有選擇權(OC67)作為過度自信之衡量方法時，金融風暴發生後相較於金融風暴發生前CEO過度自信對於公司ROA與ROE皆為顯著正相關；Chairman過度自信對於公司ROE為顯著正相關。雙元性之部分發現以股票淨購買(OCNETB)作為過度自信之衡量方法時，雙元性在金融風暴後相較於金融風暴前對於公司經營績效為顯著負相關。董事會規模與大股東持股比例在金融風暴後相較於金融風暴前對於公司經營績效為顯著正相關，但財務專家占審計委員會之比例在金融風暴後相較於金融風暴前對於公司經營績效為顯著負相關。地區集中度對於公司經營績效為顯著負相關，而長尾險種保費佔率和公司規模對於公司經營績效為顯著正相關。 This study investigates the impact of CEO and Chairman overconfidence on firm performance in the 43 U.S. publicly traded property-liability insurance companies over the period 2004-2015. This study finds the CEO and Chairman overconfidence have no significant relationship between CEO and Chairman overconfidence and the firm performance when CEO and Chairman overconfidence is measured using net stock purchase-based measure. This study also finds the CEO overconfidence has a positive impact on the return on equity (ROE) when CEO overconfidence is measured by using option holdings-based measure. This paper also investigates the relationship between the duality and firm performance, and discusses the situation of that company don’t adopt the duality, the results are no significant. The average age of directors have a significant negative impact on firm performance and the percentage of financial experts in audit committee have a significant positive impact on ROE. Also, the study finds geographic herfindahl index is negatively associated with firm performance and the percentage of long tail and firm size is positive associated with firm performance. This study also considers the impact on firm performance before and after the financial crisis. While CEO and Chairman overconfidence is measured by using option holdings-based measure, the evidence shows CEO overconfidence has a significant positive impact on ROA and ROE and Chairman overconfidence has a significant positive impact on ROE. While using net stock purchase-based measure, the results of duality is more significant negative impact on firm performance after financial crisis. Board size and the percentage of block holder is significant positive impact on firm performance after financial crisis, but the percentage of financial experts in audit committee is significant negative impact. Also, the study finds geographic herfindahl index is significant negatively associated with firm performance and the percentage of long tail and company size is significant positive associated with firm performance.
