研發扣抵政策之有效性在過去文獻有著不一致的結果，許多研究者認為可能原因之一即為與兩稅合一的衝突，實施兩稅合一之後，在有限的資金之下將增加公司發放股利的誘因；同樣的，在實施研發扣抵後亦將增加公司研發投資的金額，都會影響彼此的政策效果。 　　近年來台灣經歷獎勵投資條例、促進產業升級條例及現在的產業創新條例，其對投資之效果飽受爭論。而我國除採取研發扣抵政策外，亦實施兩稅合一政策以解決重複課稅之問題，因此在台灣兩稅合一與研發扣抵是否會互相衝突會是一項值得探討的議題。 　　本文以 1996 年至 2014 年台灣與 OECD上市公司的非均衡追蹤資料 (Unbalanced panel data) 來進行分析。實證結果指出，同時實施兩稅合一及研發扣抵的國家相較於其他樣本，其股利支付與研發投資之間的關係呈現更為顯著的負相關，代表當同時實施雙重扣抵制度，兩項支出之間的衝突性更為明顯。 　　本文另外也做了台灣與其他國家的比較，實證結果指出，台灣雖實施雙重扣抵制度，但其支出之間的關係，反而呈現較為顯著的正相關。可能的原因即為台灣之研發扣抵相較於兩稅合一，其誘因明顯為大，因此文末亦作了 difference in difference 的敏感度分析，但結果顯示不論是 1998 年兩稅合一或 2010 年產創條例實施後，研發投資與股利支付之間的關係並沒有顯著的改變。 / The effectiveness of R&D tax credit is inconsistent in past literature, and many researchers believe one possible reason is the impact of dividend imputation credit. After imputation credit, it will increase the company’s incentive to pay dividend. Also, after R&D tax credit, it will increase the payment of R&D investment. So both of the policy will affect the effect of each other. In recent years in Taiwan, we experienced Statute for the Encouragement of Investment, Statute for Upgrading Industry and current Statute for Industrial Innovation, and their effect on investment suffered controversy. In Taiwan, we have not only R&D tax credit, but also the implementation of dividend imputation to relieve the problem of double taxation, so it becomes an important issue. This paper examines the unbalanced panel data of Taiwan and OECD from 1996 to 2014. Empirical results indicate that in the context of both R&D tax credit and dividend imputation credit compared to the other sample, the negative correlation is more significant between the dividend payments and R&D investment. It means when we implement both credits, the payments of dividend and R&D conflict more. This paper also examines Taiwan with respect to OECD countries, and the empirical results indicate that although the implementation of both credits, the positive correlation is more significant between the two payments in Taiwan. One possible reason is that the R&D tax credit in Taiwan is obviously more attractive than the dividend imputation credit. Therefore, I also use the sensitive analysis of difference in difference to examine this problem. However, it shows that after the implementation of dividend imputation in 1998 or R&D tax credit of Statute for Upgrading Industry in 2010, the relationship of payments doesn’t differ obviously.

隨我國經濟發展與產業結構變遷，從經濟管制到市場自由，自勞力密集之製造出口至技術密集之產業升級，期間有不同階段之稅捐優惠作為引導。 研究發展活動具有外部正面性，同時有市場失靈之可能，私部門可能因此而不願投入、或投入不足之資源，進行研究發展活動。為獲得整體社會之最大利益，稅捐除作為財政工具，作為經濟目的之政策誘因之正當性也獲得承認。政府為促進民間投入研究發展，可能以直接補貼或提供租稅優惠方式給與鼓勵，以協助企業進行研究發展，降低跨足新興產業之進入障礙及營運風險。 但稅捐優惠之提供，乃對具相同負擔稅捐能力者，課以不同之稅捐負擔，以引導特定之作為或不作為，無可避免的違反量能課稅原則下的平等原則。何以相同負擔稅捐能力者，有不同之稅捐負擔，應有實質之說明理由。其成效與影響如何，是否達成制度上犧牲量能課稅原則所欲追求之目的，應與直接補貼接受相同程度之公開之監督與績效衡量。 就研究發展投資支出可抵減之稅額，未分配盈餘加徵百分之十部份乃為縮減營利事業所得稅與個人綜合所得稅之之實現時間差距，而研究發展投資抵減，則為分擔企業研發風險，鼓勵知識之累積，提升附加價值，兩者制定之精神互不相同，以研究發展投資抵減未分配盈餘加徵百分之十之「營利事業所得稅」，似有扞格，但兩稅合一後，營利事業所得稅在公司此一法律主體之稅捐負擔意涵已大幅下降。是以，就研究發展投資抵減未分配盈餘加徵百分之十之稅額部分，衝突程度亦獲得一定程度之解決。另外，所得基本稅額條例規定營利事業及個人皆需有一定之基本稅額負擔，此即所謂最低稅負制。所得基本稅額條例明確將研究發展投資抵減之金額計入營利事業基本稅額之計算，對之課以基本稅額，符合所得基本稅額條例施行之精神，乃合理之設計。 本文以表格方式整理方式，對照獎勵投資條例、促進產業升級條例與產業創新條例對稅基、稅率、稅額與時間歸屬之影響；針對投資抵減實務施行爭議，本研究則整理相關判決以供參考。 以上述三條例之演進趨勢而言，稅捐優惠之給予範圍已逐漸縮小，而改以直接補助或金融協助；技術開發補助與輔導；提供資訊管道、建構交易平台、整合業界、規劃工業區等行政協助，應用多元方式協助產業發展。 研究發展投資抵減之適用範圍、申請期限、申請程序、核定機關、施行期限、抵減率及其他相關實體事項，若立法之技術與資源已有相當累積，以法律位階就投資抵減作較具體之規範，應為立法機關所考慮。 / Abstract With the economic development and the changing in industry structure, from economic regulation to an open market, and from labor-intensive to technology -intensive, the government is guiding the market by tax incentive and other kinds of tool. Because R&D has positive externalities, barriers to entry and the possibilities of market failure, private sector may not willing to input resource for R&D. For social welfare maximization, the government may use tax incentive to encourage private sector to do R&D. By provide R&D Tax Credit or subsidy , the government can encourage the private sector to do more R&D. But providing tax credit will unavoidably conflict with Principle of Ability to Pay. There should be a reason for why people have the same ability to pay the tax pay different tax. The same supervise and performance evaluation must be done for tax credit and subsidy. For 10% surtax on Retained Earnings is to narrow down the time difference between the realized of corporation tax and individual income tax, and the R&D credit is for sharing risk of failure, encouraging research and development, and rising EVA, the tax which can be credited should not include surtax on Retained Earnings. But with the applying of Integrated income tax system, the conflict has been partly solved. For Alternative Minimum Tax, R&D expense can’t be credited is a reasonable design. This paper mainly focus on comparing the differences of tax base, tax rate, and income tax payable etc. in the Enactment of Encouragement Investment, the Statute for Upgrading Industry, and the Statute for Industrial Innovation. Also sued cases were collected to report any violations of existing R&D policies for future amendment concerns. The range of tax credit is shrinking, and is replaced by subsidies, industrial technology development programs, and the setting of science parks etc. And for principle of taxation under the law, The Statute for Industrial Innovation should be ruled in law by the legislative.