私募股票報酬與高階經理人過度自信之關聯性分析

Abstract

使用私募籌資的上市上櫃公司近年不斷增加，已成為資本市場上常見的募資管道。國內外文獻不乏討論私募股權對於私募過後之股票報酬的影響；然而，目前之相關研究尚未與高階經理人過度自信的議題所連結。實證研究指出短期私募股票之宣告效果顯示為正，但近年來亦有研究指出與上述實證相左的例子。如壕溝效果指出管理者藉由大量發行私募股票予消極投資者，以鞏固自己對於公司之影響力；此效果將導致私募股票之宣告效果產生負異常報酬。我們將壕溝效果與高階經理人過度自信之現象相連結，探討過度自信的高階經理人在從事私募股權時是否較容易產生壕溝效果。本研究分短期宣告效果與長期股票報酬兩部分做探討，並將樣本分為過度自信群組與非過度自信群組進行研究分析。實證結果在短期指出私募股權公司若存在過度自信之高階經理人有較高的機率使宣告效果產生負異常報酬；長期而言並無顯著結果指出兩群組之股票報酬有所不同。

Nowadays, private placement becomes a common financing method in capital market, and there are increasing numbers of company using private placements to finance capital. Existing studies suggest that firms announcing private placements follow positive stock performance. Nevertheless, entrenchment effect which leads the negative announcement effect of private placements is supported in recent years. We note that private placements have not linked to CEO overconfidence in the prior literature. Therefore, in this study, we test if overconfident CEOs affect stock performance following private placements. In empirical results, we find that firms with overconfident CEO perform worse than those with rational CEOs when they announce private placements. However, no significant difference exists in firms with overconfident CEO.