經理人過度自信、會計穩健性與股價崩跌風險

本研究旨在探討過度自信的經理人如何影響會計穩健性與股價崩跌風險之間的負向關係。過去研究發現，會計穩健性有助於抑制負面消息隱藏的行爲。然而，過度自信的經理人通常伴隨潜在代理問題，當有負面盈餘消息時，他們會對未來樂觀並相信自己有能力扭轉負面消息而傾向不揭露，因而產生較高的股價崩跌風險。因此，本文將討論過度自信經理人、會計穩健性與股價崩跌風險三者的相互關聯性。本研究以台灣2008年至2020年上市櫃公司為樣本。實證結果顯示，會計穩健性與股價崩跌風險的負向關係在公司經理人過度自信時較明顯。本文也進一步證明了當其他公司治理機制較差時，此負相關會更顯著。這主要是因爲會計穩健性作爲公司治理不可或缺的一環，與其他公司治理機制互爲替代關係，從而減輕由過度自信經理人引發的代理問題與壞消息隱藏帶來的後果，進而降低股價崩跌風險。本文的貢獻在於從經理人特徵與資本市場的角度，補充了關於會計穩健性與其他公司治理的替代性關係的研究。

關鍵字

股價崩跌風險；會計穩健性；經理人過度自信；公司治理

並列摘要

The purpose of this paper aims to examine how overconfident chief executive officer (CEO) can influence the negative relationship between accounting conservatism and future stock price crash risk. The past findings indicated accounting conservatism could prevent bad news from accumulating and withholding to some degree. Overconfident CEOs are often associated with potential agency problems and they may be optimistic about the future and believe the concealed bad news would reverse, which can lead to stock price crashes. Therefore, it is interesting to investigate the relations among overconfident CEOs, accounting conservatism and stock price crash risk. Using the data of companies listed in Taiwan from 2008 to 2020, the empirical results indicate that the negative correlation between accounting conservatism and stock price crash risk is exacerbated when firms with overconfident CEOs. Furthermore, the additional test shows this significant negative effect is more pronounced when firms have weaker other corporate governance mechanisms, because accounting conservatism, an important role in corporate governance, could alleviate potential agency problems and further decrease crash risk. Overall, this study complements the existing literature on the substitutive between accounting conservatism and corporate governance from managerial characteristics and capital market perspective.