供應鏈中資訊不對稱對公司股票購回的影響

Abstract

根據2003年到2008年的美國實證資料，本文將探討公司股票購回所造成的影響、資訊不對稱與供應鏈特性之間的關係，以及其對公司超額股價報酬和超額債券價格報酬的影響。我們發現在公司在進行股票購回後，資訊不對稱不但降低外，對公司的股東和債權人也造成正面影響。本文亦驗證了股票購回後，訊號效果與財富移轉效果皆存在，不過其中訊號效果只維持了一個月。此外，本文發現在考慮了公司供應鏈中上下游的資訊不對稱程度後，將會抵消因公司資訊不對稱程度所帶來的資訊溢酬效果，此現象尤其在供應鏈上游更顯著

Using U.S. data from 2003 to 2008, this study explores the effects of share repurchase and changes of information asymmetry level of repurchasing firms and its supply chain members on abnormal equity returns and abnormal bond returns. Empirical results show that information asymmetry level of repurchasing firms decreases after share repurchases which benefits stockholders and bondholders. This study also indicates that signal and wealth transfer effects do exist after repurchases while signal effect lasts only in one month. Furthermore, results of this research reveal that information premium effect due to the decline of information asymmetry level of repurchasing firm is offset by information advantage effect of supply chain members, which is more significant for the supplier-side.