本研究旨在探討我國實施兩稅合一制度後，稅額扣抵比率及未分配保留盈餘加徵10%營利事業所得稅在上市公司不同產業間的實行狀況，以及新稅制對上市公司資本結構及資金成本的影響，並評估這些結果是否有達成政府實施兩稅合一政策的主要目的，改善企業的資本結構及創造有利於企業的投資環境。本研究的研究範圍以兩稅合一實施前後，自民國85年至88年共四年度在台灣證券交易所之股票上市公司為研究樣本。 本研究結果顯示，在稅額扣抵比率方面，由於電子業上市公司相對於非電子業上市公司享有較多的租稅優惠，故其稅額扣抵比率顯著地低於非電子業上市公司。此外，在未分配盈餘加徵10%營利事業所得稅方面，民國88年度，我國被加徵未分配盈餘稅的上市公司中，大約有15%的公司民國87年度並無財務所得，但依所得稅法第六十六條之九計算的未分配盈餘卻為正值，顯見現行以課稅所得為基礎計算的未分配盈餘與財務會計的處理結果有很大的差異。至於未分配盈餘加徵的稅額，我國電子業上市公司即約佔38%，且其加徵稅的平均值也遠高於全部樣本之平均值。 在兩稅合一實施前，舉債較高且租稅負擔較低的公司，兩稅合一實施後，因新稅制減少了企業對於融資決策的扭曲，故有助於財務風險較高的公司改善資本結構。此外，公司的稅額扣抵比率愈高，則其舉債比率愈低。再者，在兩稅合一實施前，舉債較少且租稅負擔較高的公司，兩稅合一實施後，資金成本的變動呈現上升趨勢，與本研究預期相反，但本文實證結果仍發現公司的稅額扣抵比率愈高，則其資金成本愈低。因此，兩稅合一對於企業資金成本的降低仍具有效益。

我國過去之所得稅制乃是採營利事業所得稅與個人所得稅並行之制度，此種對股利所得的重複課稅，扭曲了企業籌措財源的方式，使得公司傾向於以舉債的方式籌措資金，並扭曲了企業盈餘分配之決策、造成稅法之複雜性及稅務行政的複雜化。在經過政府及相關部門多年來之努力，我國於民國八十七年一月一日起正式實施兩稅合一新制。本文之目的即在藉由探討兩稅合一之各相關事件日股票異常報酬之變化，以觀察台灣股票市場對新稅制的反應，實證結果可供未來修正或訂定類似政策參考。 為探究兩稅合一之各相關事件日股票異常報酬變化之產生原因，本研究檢定公司有效稅率、盈餘保留率及股東個人邊際稅率是否足以解釋各相關事件日之股票異常報酬。實證結果顯示，公司有效稅率確會影響各相關事件日之股票異常報酬，且與本研究所預期之方向相同，為正相關，顯示市場也認為在兩稅合一之下，預期有效稅率愈高的公司，其因為兩稅合一所得到的利益也會愈大。但在盈餘保留率及股東個人邊際效率方面，卻無法獲得滿意的實證結果，其可能原因有二：第一，歷史資料可能無法有效替代預期之保留盈餘比率。第二，董監持股比率可能無法有效作為股東個人邊際稅率之替代變數。 / The major deficiency of Taiwan's past tax system was that the business income was taxed twice: once at the corporate level and once at the individual level. This system significantly distorts companies' financing strategies, and companies tend to get the needed fund by issuing bonds. Besides, it also distorts the way companies allocate their earnings and causes taxes and tax-related administrations to be very complicated. However, after great efforts made by the Department of Treasury since 1996, the new tax system-"Integrating individual and corporate taxes" became effective from the beginning of 1998. The main purpose of this thesis is to examine the market reactions to the new system by studying the variations of the abcdrmal returns of stock prices at event days related to this new tax system. The empirical results could be used for amendments or the making of similar policies in the future. To study reasons that variations of abcdrmal returns of stock prices at the event days of this new tax system exist, this study tests weather Corporate Tax Rate, Retention Rate of Earnings and Individual Tax Rate can explain the abcdrmal returns of stock prices at the related event days. Empirical results show that Corporate Tax Rate affects the abcdrmal returns of stock prices at the related event days, and the direction is the same as expected, which is positive-correlated. The result shows that "the market" also thinks under the new tax system, the higher the expected Corporate Tax Rate, the higher the benefit from the new tax system will be. However, for the Retention Rate of Earnings and the Individual Tax Rate, the results are unsatisfactory. Two reasons are possible: first, historical data probably cannot represent the expected Retention Rate of Earnings. Second, the ratio that stocks held by members of board of directors is not a good proxy for the Individual Tax Rate effectively.

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.

本研究主要在探討近年來兩大租稅改革：兩稅合一制及最低稅負制之施行對上市公司外資持股比率之影響，是否降低外資持有我國上市公司股票之意願，影響我國企業的股權結構。 兩稅合一制施行後，消除股利所得之重複課稅，國內法人股東與自然人實質稅負減輕；但根據所得稅法第七十三條之二規定，非中華民國境內居住之個人、在中華民國境內無固定營業場所及營業代理人之營利事業，其獲配股利所含之稅額，不得扣抵其應納稅額，外資無法享受股東可扣抵稅額消除重複課稅的好處，外資在台投資實質總稅負仍維持為40%，較境內自然人股東之實質稅率6%~40%為高，股東可扣抵稅額比例愈高，外資損失越大。再者，最低稅負制施行主要影響對象為外資持股最多的電子業，且最低稅負制之施行對於公司補繳之稅負，外資股東也無法享受股利抵稅權。故可推論兩稅合一制、最低稅負制之施行及股東可扣抵稅額與上市公司外資持股比率應呈負向關係。 本研究之樣本為民國85年到民國95年及最低稅負制前、後之台灣上市公司。主要實證結果彙整如下： 1、兩稅合一制之施行及股東可扣抵稅額與上市公司外資持股比率呈負向關係，最低稅負制之施行與上市公司外資持股比率呈正向關係，但其效果應為股價指數之影響所致而非最低稅負制之施行；又最低稅負制施行後，外資仍偏好持有公司有效稅率低於10%之股票。 2、另外以民國93年到民國95年資料額外檢測，最低稅負制下限制投資抵減金額之效用，推論投資抵減金額在最低稅負制施行後與上市公司外資持股比率應呈負向關係，實證結果為負向關係但不顯著。 / The objective of this study is to examine whether the implementation of the Imputation Tax System and Alternative Minimum Tax System will affect the willing of foreign investors to invest in listed companies. The sample of this study consists of firms listed in the Taiwan Stock Exchange from 1996 through 2006. The empirical results in this research are summarized as follows: 1、 The implementation of the Imputation Tax System and a firms' imputation tax credit ratios have a negative impact on the percentage of foreign ownership in listed companies, but the implementation of Alternative Minimum Tax System has a positive impact on that. We conduct further examination and find the increasing effect of the percentage of foreign ownership is more rely on the effect of stock index than that of the implementation of Alternative Minimum Tax System. Further, foreign investors still prefer to invest in listed companies whose effect rates are lower than 10%. 2、With the implementation of Alternative Minimum Tax System, the use of investment tax credit was restricted. The empirical result of this study shows that after the implementation of Alternative Minimum Tax System, the investment tax credit has a negative but not significant impact on the percentage of foreign ownership in listed companies.

Mainland China has implemented two sets of income taxes systems for many years. One is for the foreign enterprise “1991 Promulgated Foreign Invested Enterprise and the Foreign Enterprise Income Tax Law” and another one to the domestic enterprise, “1993 promulgated Enterprise Income Tax Temporary Regulation”. The coexisted of two taxes not only resulted in unfair taxation but also created fake foreign enterprise phenomenon. It is especially difficult for people to accept this situation after China joined the World Trade Organization. The legislation conditions matured after speedy growth of Chinese economy. The Chinese government considered the current financial situation can withstand the impact on decrease in tax revenue after new tax law implemented and it met one of the current economic development targets of “nurture domestic enterprise”. On March 16, 2007, the “Enterprise Income Tax Law of the People's Republic of China” (here in after referred it as the New Law) was eventually approved after many years of research. It surely will have profound influence on foreign enterprise including the Taiwanese businessmen. The purpose of the study is how the major changes of the New Law impacts the China investment of the Taiwanese businessmen. The structure of the study, other than abstract and conclusion, firstly, the author will discuss of the content of system and policy changes. Next, based on the major changes of the New Law, how they affect designed research method. Analyze and forecast its possible impact and influence on Taiwanese businessmen in the following categories: (1) tax incentive; (2) organization structure organization, and (3) tax risk. Finally, the author will propose the related action taken and suggestions on the impact.

本論文分五章探討，第一章為緒論。 第二章為中國大陸企業所得稅法的立法沿革介紹及發展史。在此，介紹了中國從1950年開始至今50多年來中國稅制的演變。 第三章開始探討企業所得稅制的發展歷程，由於過去中國急於發展，稅制主要目的在於吸引資金，對外資企業設立許多租稅優惠，但在這樣的大環境之下，卻產生了許多不公的情況。內外資企業所得稅分立並行，兩套稅制在稅基、稅率、稅收優惠等方面都不統一，且外資企業享有大量租稅優惠，相較之下，內資企業成為弱勢，不利市場公平競爭，為納稅人避稅和偷稅提供相當大的誘因。另外，在第四節的部分，談的是新企業所得稅法的改革重點及內容介紹，並對新舊制度做出比較。 第四章談的是新企業所得稅法施行的問題點。本章將新法規定較模糊或是較晚公布細則的地方做出釐清，並談論在新法之下，有哪些合法的避稅管道可供使用。在第二節的部分藉由數據證明，新企業所得稅法雖然取消了許多外資企業的租稅優惠，但在2008年一整年的稅收比2007年來得要多，這說明了，修法只是一個國家制度的完善與健全，資金流向中國的原因並不全然是租稅優惠的關係，而是由於中國擁有資源及良好的投資環境等因素。 第五章為結論與建議。

我國所得稅法自民國八十七年一月一日開始實施兩稅合一制度。這原本是政府一項消除重複課稅的美意，但是仍受到多方批評。其爭議點就在於「未分配盈餘加徵百分之十營利事業所得稅」這項配套措施的實施。許多專家學者認為，對企業的未分配盈餘課稅，不利於企業內部資金的累積，進而影響其創新活動的投入與產出。而財政部卻持有不同的看法。 基於上述爭議，本研究以迴歸模式探討「未分盈餘加徵百分之十營利事業所得稅」制度的實施，對企業創新活動的影響。經實證結果發現： 1.對企業未分配盈餘加徵10%營利事業所得稅，確實會影響企業資本形成，降低其創新活動。因此，為求稅制良善，促進國家經濟發展，政府對於稅制之設計應謹慎為之。 2.以高科技產業和傳統產業比較，高科技產業由於兩稅合一未分配盈餘加徵10%營利事業所得稅制度的實施，其創新活動較制度實施前縮減，且縮減程度明顯大於傳統產業。此結果顯示，高科技產業顯然可謂新稅制下的最大受害者。因此，對高科技產業之未分配盈餘加以課稅，無疑是形成其創新活動的絆腳石、增加其營運上的風險。政府對此情況，應予正視。 3.以融資受限公司和融資未受限公司比較，兩稅合一之未分配盈餘加徵10%營利事業所得稅制度對融資受限公司之影響不大。經分析樣本特性，發現融資受限公司的獲利能力較差，因此租稅課徵對於其所造成的影響較低。因此可推論，獲利能力差之融資受限公司的創新活動受到非租稅因素的影響比租稅因素來得大。 關鍵字：未分配盈餘加徵百分之十營利事業所得稅，兩稅合一，創新活動 / In response to the public concern, Taiwan has adopted the imputation tax credit system since January 1st, 1998. Although the new tax reform can eliminate double taxation, the implementation of additional 10% surtax on undistributed surplus earnings has engendered lots of comments. Based on the disputations resulted from the new tax system, we conduct an empirical research analyzing the impacts of the implementation of additional 10% surtax on undistributed surplus earnings on the enterprises’ innovation. The empirical results in this research can be summarized as follows: 1. Imposing 10% surtax on corporate undistributed surplus earnings has adverse effect on capital accumulation, in turn leading to reduction in incentive of enterprises to conduct innovative activities. 2. Compared to the traditional industry, adverse effect of this new system is more profound for firms in the high-tech industry. The results indicate that high-tech industry is the major victim under the new tax reform. Therefore, imposing additional 10% surtax on high-tech industry will be an obstacle to enterprises’ growth and increase its operating risks. 3. Compared to unconstrained firms, we find out that the new tax system have less effects on constrained firms. Owing to considering the poor profitability, we can infer that non-tax factors have greater influence on the innovation of constrained firms relative to tax factors. Key words: additional 10% surtax on undistributed surplus earnings, the imputation tax credit system, innovation

依據財務會計理論，附註揭露為整體財務報表的一部份，其目的在提供投資人進行企業評價時所需之攸關資訊。兩稅合一制度實施後，不僅使稅賦型態轉變，會計原則中也新增附註揭露股東可扣抵稅額之規定，因此提供了驗證資本市場與財務報表揭露的機會，本研究即針對股東可扣抵稅揭露是否具有價值攸關性進行測試。 本研究以87年為樣本年度，分析資料完整的317家上市公司，透過Ohlson模型來檢測股東可扣抵稅額之價值攸關性，並處理Ohlson模型中兩個重要的information dynamics，以異常盈餘（xa ）及其他資訊（v）做為模型中的自變數，將財務分析師之財務預測（analysts’forecasts）做為Ohlson模型中其他資訊（other information）之代理變數，以捕捉Ohlson模型中其他資訊對股價的影響。最後，考慮產業及公司規模兩項因素，觀察紡織業與電子業對股東可扣抵稅額揭露之反應以及公司規模對於價值攸關性研究的影響。 實驗結果顯示，無論以現金基礎或應計基礎衡量股東可扣抵稅額，其揭露均具價值攸關性，投資人的確使用財務報表附註揭露中有關股東可扣抵稅額之資訊於企業評價上。其次，異常盈餘與其他資訊皆能捕捉股價之變動。最後，在紡織業與電子業中雖未觀察到股東可扣抵稅額之揭露具有攸關性，但公司規模的因素則無論在全體樣本或各別產業中皆具影響力。 / According to modern accouning theory, footnote disclosures are an intergrated part of the overall financial statements. The purpose of footnote disclosures is to provide value-relevant information in assisting investors’ valuation process. After Taiwan’s 1998 Tax Reform, which intergrates the individual and corporate taxes, the current GAAP requires a footnote disclosure of imputation credits (IC). This provides a good chance to test how Taiwan’s stock market reacts to such disclosuer. The main purpose of this study is to examine the value relevance of IC disclosure to investors’ equity valuation. This study uses Ohlson’s (1995) model to analyze 317 firms listed on Taiwan’s Stock Exchang (TSE) during 1998. To estimate the abcdrmal earings and other information (captured by analysts’ forcasts), this study adopts Dechow, Hutton, and Sloan’s(1999) methodology. We also investigate the effects of industry and firm size on the value relevance of IC disclosure. The empirical results reveal three findings. First, there is a positive association between IC and stock price in TSE. Therefore, the IC disclosure is value relevant to investors’ equity valuation. Second, abcdmal earnings and other information can both explain stock price behavior. Finally, when we focus our sample on the textile and high-tech industries, no significant association between IC disclosure and stock price can be found. When we further consider firm size, however, the value relevance of IC disclosure becomes significant. In other word, the value relevance of IC disclosure may be affected by firm size.

本論文探討兩稅合一制所增設的兩個機制，即稅額扣抵比率及加徵保留盈餘稅對上市公司股利發放、資本結構以及公司租稅規劃的影響。首先以數學模式推導出兩稅合一制下這兩個機制與股利發放率及負債權益比率之間的關係，再據以建立研究假說，而後進行兩步驟多變量程序之實證測試。研究所獲致的結果包括： 　　一、兩稅合一制實施後，上市公司稅額扣抵比率與總（盈餘）股利發放率呈正相關，且上市公司稅額扣抵比率愈高者，其總（盈餘）股利發放率、現金股利發放率及盈餘配股發放率皆較兩稅合一制實施前高。由於公積配股並不受兩稅合一制實施的影響，故本文也發現兩稅合一制實施前後公積配股率並無顯著差異。整體而言，兩稅合一制實施後，總（盈餘）股利發放率、盈餘配股發放率及公積配股率較實施前減少，而現金股利發放率較實施前增加。進一步的分析顯示現金股利發放率的增加係受到健全股利政策的推行影響，而盈餘配股發放率的減少可能是受到股票股利緩課取消的影響。 　　二、兩稅合一制實施後，符合促進產業升級條例第八條及第九條規定之投資方案，選擇股東投資抵減之公司並無顯著多於選擇五年免稅之公司，可能原因為選擇五年免稅有利於公司現金流量及每股盈餘的金額。此一結果雖與預期方向相反，但也顯示政府原先擔心公司會選擇股東投資抵減而造成鉅額稅收流失的疑慮並未獲得實證支持。但從兩稅合一實施後公司股權結構的變動分析顯示，公司法人持股比率較實施前增加，而僑外投資持股率較實施前減少，支持公司在不同股東身分稅負差距的考量下，會有股權結構移轉之租稅規劃，以降低股東所負擔的稅負。 　　三、兩稅合一制實施後，上市公司稅額扣抵比率愈高者，股東所享扣抵權愈多，則舉債租稅利益愈少，因而總負債權益比率將降低；而上市公司保留盈餘比率愈高者，所課徵的保留盈餘稅愈高，舉債利息的租稅利益反而增加，會造成總負債權益比率增加。本文的實證結果也顯示，兩稅合一制實施後，上市公司稅額扣抵比率愈高者，其總負債權益比率較實施前低；而上市公司保留盈餘比率愈高者，其總負債權益比率較實施前高。 　　綜合本論文實證結果顯示，兩稅合一制實施後，稅額扣抵比率的機制確實其有消除股利所得重複課稅的效益，進而提高公司股利發放的意願，並且有助於公司資本結構的改善。但是，政府對於未分配盈餘加徵 10％營利事業所得稅的規定卻不利於公司資本的累積，反而提高舉債的租稅誘因，也可能抵銷稅額扣抵比率降低舉債的效果，值得政府深入檢討對公司未分配盈餘課稅的不利影響。 / Enacted in 1998, the Integrated Income Tax System has two important features, i.e., the imputation tax credit to shareholders and the 10% surtax levied on undistributed earnings. Using two-step multivariate regression, this study exmines the impacts of these two features on corporations' dividend payout, tax planning, and capital structure. The findings of this study are as follows : 　　1. After implementation of the Integrated Income Tax System, the imputation tax credit ratio is positively related with total dividends payout ratios. Companies with higher imputation tax credit ratios tend to pay out more cash dividends and earnings stock dividends, ceteris paribus. However, there appears no significant relation between the imputation tax credit ratio and capital stock dividends. On average, after implementation of the Integrated Income Tax System, stock dividend payout ratios, including earning stock dividends and capital stock dividends, are decreased, but cash dividend payout ratios are increased. The increase in cash dividend payout may be affected by the balance dividend policy by the SEC, which require corporations to pay out greater proportions in cash dividends. The decrease in earning stock dividends may be due to the cancellation of the deferral of tax on stock dividends. 　　2. After implementation of the Integrated Income Tax System, inconsistent with the expectation, companies still prefer the five-year tax exemption to the investment tax credits. The results suggest that companies' choices are affected more by such factors as corporate cashflows and earnings per shares. However, after implementation of the Integrated Income Tax System, there is a significant change in stockholder structures, with the ratios of corporation stockholders being increased while the ratios of oversea stockholders being decreased. The opportunity of tax arbitrage will have a significant impact on corporations' stockholder structures. 　　3. After implementation of the Integrated Income Tax System, for companies with higher imputation tax credit ratios, their stockholders will have greater tax benefits, and, hence, the tax benefit for companies to use debt financing is decreased. Conversely, companies with higher ratios of retained earnings will bear more tax burdens on the 10% surtax levied on undistributed earnings; therefore, the tax benefit of debt financing is increased. The empirical results support that, ceteris paribus, companies with higher imputation tax credit ratios tend to have lower debt-to-equity ratios, while companies with higher ratios of retained earnings tend to have greater debt-to-equity ratios. 　　In summary, after implementation of the Integrated Income Tax System, the imputation tax credits reduce the double taxation on stockholders' dividend income and, hence, improve corporations' capital structure. However, the 10% surtax on undistributed earnings may result in opposite effect on corporations' capital structure. The findings of this study have important implications for the government to take into account the potential adverse impacts resulted from taxes levied on corporations' retained earnings.