資金來源對股票購回之影響－以信用風險觀點探討

Abstract

不同於過去文獻以異常報酬作為依據，本研究藉由分析一個反應信用風險變化的變數，重新檢視公司宣告買回股票是否產生訊息效果以及財富移轉效果。實證結果顯示，正向的訊息效果大過財富移轉效果，亦即公司信用風險並無惡化，債權人的權益沒有受到損害。宣告購回的規模愈大，正向訊息效果超過財富移轉效果的程度就愈大。此外，以舉債融資買回股票的公司比起內部融資者釋放出更多的正面訊息，但其信用風險增加幅度亦較大，因此整體而言舉債融資的公司在股票購回宣告後信用好轉的程度較小。

We employ a credit innovation proxy to revisit the signaling and wealth transfer effects around stock repurchase announcements documented in prior researches. Using panel data from 1991 to 2006, we find evidences that positive signaling effect dominates wealth transferring one, which means, overall speaking, stock repurchases do not expropriate bondholders’ wealth. The total benefits from stock repurchase are positively related to the size of repurchase. Besides, firms finance the repurchases with debt, comparing with no debt, exhibit greater positive signals, while the effect is abated by higher default probabilities due to a raise in debt level.