本文針對子公司操作母公司股票資料作有系統的檢視,並參考公開市場股票購回(open market repurchase)與釋股(seasoned equity offerings)的訊號假說作實證分析。主要實證結果如下:第一、子公司操作母公司股票的操作行為與公開市場股票購回、釋股的訊號假說不一致。第二、以大股東質押比例會作探討代理問題的變數,贊成大股東質押比例與買入操作比例和淨操作比例呈正相關,顯示子公司操作母公司股票的動機可能與鞏固大股東個人利益有關。第三、高內部人持股比例的母公司益不會積極利用子公司買進自家股票,而是消極地減少持股賣出。第四、在金融風暴期間,母公司為集團公司時,其子公司操作母公司股票的程度顯著小於非集團的母公司。本文證據顯示子公司的投資決策明顯受到母公司影響,具有「機構內部人」的角色特質。
This paper investigates the behavior of a subsidiary's trading in parent stocks. Empirical results are compared to those of open-market repurchases and seasoned equity offerings. We find several interesting observations. First, the trading behavior is not consistent with the signaling hypothesis implicated in open-market repurchases or seasoned equity offerings. Second, large shareholders' stock collateral ratio, a proxy for agency problem, is positively correlated with buying and net buying ratios. This finding is consistent with the prediction of entrenchment hypothesis. Third, the subsidiaries tend to trade less actively on parent stocks if the parent company is closely held. Fourth, during the Asian Financial Crisis , the subsidiary's trading in parent stocks is significantly less active if the parent firm is a conglomerate. The overall evidence suggests that the investment decisions of subsidiaries are deeply influenced by their parent companies and therefore lends support to our institutional insider hypothesis.