本文主要是透過Michael Jensen (1986)的自由現金流量假說(Free Cash Flow Hypothesis),檢視公司管理階層是否會利用研究發展(Research and Development,簡稱R&D)支出增加來追求其本身的私利,以及R&D異常支出是否會影響該公司的股票報酬。 本文以台灣上市(櫃)公司為研究對象,蒐集從1996至2008年公司財務報表中所認列研究發展費用,其符合R&D支出異常增加之樣本資料。依循Titman,Wei and Xie(2004),我們將樣本分為五個R&D投資組合,利用Fama and French 三因子模型檢驗在R&D異常支出和未來股票報酬間的關係。 實證結果發現,R&D支出增加後公司股票報酬確實存在正的異常報酬,顯示R&D支出增加是一項有利的投資活動;但此異常報酬隨著R&D異常支出增加幅度加大而呈現遞減的跡象,顯示R&D支出異常增加時,對股價較有不利之影響,亦即,在R&D支出增加的公司事件上,自由現金流量假說仍是成立的。其可能原因是,台灣屬淺碟型市場,投資者進出股市頻繁且投資期間較短,R&D投資往往需要較長時間其研發成果才能呈現。 因此,投資人可選擇R&D支出異常增加但增加幅度不大的公司股票進行投資,除了可享R&D支出增加的股票增值利益外,亦可降低R&D支出增加所引發的代理問題,進而提高股票投資報酬。就股東而言,適度的R&D支出增加對公司價值有利,但R&D投入過多反而會造成股票報酬下跌,因此應要求合理的股利發放;而政府部門若發現公司有過度R&D支出以追求私人利益的現象,應加強管理監督。
This present study applies revised Jensen’s (1986) Free Cash Flow Hypothesis to investigate whether top managers pursuit their private benefits by using research and development (hereafter R&D) increases, and the effect on abnormal stock returns of firms following increases in R&D. First, from July 1996 through June 2009, the abnormal returns are measured over 156 months (13 years) following the unexpectedly increases in R&D for 936 firms listed on the TSE. Second, We divided R&D samples into 5 portfolios accordng to R&D intensity, which base on the methods developed by Titman,Wei and Xie(2004). Furthermore, we use the three-factor model (Fama and French, 1993) to calculate the expected returns of securities. The empirical results show that R&D increase is a favorable investment activity, but its excess returns are declining after R&D unexpectedly increases. This is consistent with the spirit of Free Cash Flow Hypothesis.