過去國外文獻大多探討增加R&D投入對未來公司績效有正面影響或是減少R&D投入對未來公司績效有負面影響。而在減少R&D投入對未來公司績效有正面影響的議題上,目前僅有少數幾篇國外文獻採用美國資料作為實證分析,而國內尚未探討相關的研究議題。因此,本研究欲針對臺灣產業探討減少R&D投入後,未來公司股價是否存在異常報酬以及經營績效方面是否有顯著變化。此外,本研究以研發強度將全樣本劃分高研發強度產業與低研發強度產業,在股價報酬的部分,使用買進持有異常報酬法以及日曆時間投資組合法計算異常報酬。 結果發現全產業與低研發強度產業皆呈現顯著的負向異常報酬,這樣的結果與Eberhart、Maxwell & Siddique(2004)觀點相互一致,發現臺灣股票市場對於R&D減少所產生的損害有呈現反應不足的現象,也提供一個合理的解釋說明效率市場假說的不存在;經營績效的部分,除了探討減少R&D投入後各期間的經營績效之外,更進一步探討在一段期間內經營績效的變化,結果發現,高研發強度產業呈現半顯著的正向異常績效,搭配其長期異常報酬結果來觀察,可以推論出高研發強度產業符合R&D外溢效果假說;低研發強度產業則呈現半顯著的負向異常績效,搭配其長期異常報酬結果來觀察,可以發現在低研發強度產業中,減少R&D投入除了使投資人產生錯誤反應現象之外,也更加支持著減少R&D投入是不佳的投資決策。
Most of the literatures on R&D only demonstrated if increase in investment of R&D has a positive impact or negative impact on the company's future performance. Only few of them examine how reduction in R&D investment may have a positive impact on the company's future performance in United States. As Taiwan having no previous research on this issue, this study attempted to explore how reduction in investment in R&D generate significant changes in operating performance and abnormal returns by making use of the data including stock price from Taiwanese industries. In addition, this study categorizes the targeted industries into two groups: industries with high intensity of R&D and industries with low intensity of R&D. With calculating the abnormal returns by using the buy and hold abnormal returns method and calendar time portfolio method, the result, which coincide with Eberhart、Maxwell and Siddique(2004) point of view, reveals that the whole industry and industries with low R&D intensity have a negative abnormal returns; therefore, it provides a significant counterevidence for the efficient market hypothesis. For the part of investigating operating performance. The result manifests that industries with high R&D intensities have a significant positive abnormal half performance; combining the observation of their long-term abnormal returns, it can conclude that the performance of industries with high intensity of R&D consist with R&D spillovers hypothesis. Moreover, industries with low R&D intensity show a half significant negative abnormal performance. With observing the long-term abnormal returns, we can also conclude that industries with low R&D intensity provide an wrong signal to investor; also, reduction in R&D is definitely a inefficient decision of investment.