本研究取得財政部財稅資料中心提供之2011年至2014年我國遺產及贈與稅核定資料，利用這份遺產及贈與稅之核定資料，計算出我國此四年遺產稅以及贈與稅之有效稅率。此外因一年內或資料期間內單一贈與人可能存有多次贈與的情況，故本研究另外依照同一贈與人為單位，合併同一贈與人之贈與資料計算其有效稅率，以及依照贈與次數分組計算之贈與稅有效稅率。透過本研究之遺產及贈與稅有效稅率計算及透過分位有效稅率的討論，可以了解到我國遺產及贈與稅，在改為單一稅率10% 後之實際負擔情形。

遺產及贈與稅的課徵具有實現社會公平的正面意義，但開徵至今，不僅稅收不豐，更因租稅規避行為普遍而失去效率，我國遂於2009年針對遺產及贈與稅制進行大幅改革。 　　本研究以美國、香港及新加坡的稅制實施與改革經驗為借鏡，輔以財政部國稅局的實際課徵數據，探討此次遺贈稅制改革的內容與影響。研究發現，此次遺贈稅改的影響，於短期會造成遺贈稅的稅收損失，但就長期而言，因稽徵效率提升及降低民眾跨期與跨區配置資源的條件限制，可增進整體社會資源的配置效率。此外，調降後的遺贈稅稅率約與租稅規劃成本相當，可望減緩我國資金外流的情形；惟仍須配合國內政治、經濟及社會環境之發展，方有足夠誘因吸引資金回流。 　　是故，本研究建議政府機關應有明確之政策發展方向，如欲以租稅政策促進經濟發展，應先正視我國目前面臨的競爭環境及資金流向問題，塑造優良投資環境，方能吸引資金回流，活絡我國經濟並培養適當稅源。再者，亦應確立遺贈稅制之定位，於未來改革方向，不論再降稅或廢除，均應規劃妥善之配套措施，使我國整體賦稅制度更臻完善。 / The estate and gift taxes are most often justified by the need to ensure a particular sense of fairness in the overall tax system. However, the two contribute to a rather insignificant share to total tax collection, and also encourage widespread tax avoidance. Thus, many economists argue that the estate and gift taxes are hard to justify on either efficiency or equity grounds. For these reasons, the Estate and Gift Tax Act in Taiwan was substantially revised in January, 2009. The main purpose of this study is to explore the major revisions and the impact of the tax reform, supported by the financial statistics offered by the Ministry of Finance, R.O.C. The results of this study indicate that the significant revision will lead to a reduction in tax revenue in the short term. Neverthetheless, it will make the allocation of resources in the economy more efficient in the long term, since the collection efficiency of the two taxes improves and the restriction on allocation of resources for the public is reduced. Besides, the new tax rate is nearly equal to the cost of tax planning, so the capital outflow may be eased off. If the government and regulatory bodies also improve the investment environment, it will attract more foreign capital back to Taiwan. Based on the above, this study provides some suggestions for the tax administration. First, it is necessary to set a clear policy direction. If policy makers intend to use tax policies as a tool for promoting economic development, it is important to address the issues which our country currently encounters with, including the competitive economic environment and where the capital flows to. Only with the better investment environment, can our country attract more international capital to invest in. Second, tax administration must establish the role played by estate and gift taxation in our tax system. Any reforms of the estate and gift taxes must entail a set of complementary measures, so that our tax system could be fairer and more efficient.

面對經濟景氣停滯、財政赤字急遽惡化及相關社會福利支出等種種不利因素，我國政府在衡酌國際金融危機及稅制改革潮流下，於2009年將遺贈稅之最高邊際稅率由50％大幅調降為單一稅率10％，同時提高免稅額。就修法目的而言，主要希望藉由稅率的降低來吸引海外資金，並預期此項租稅改革能振興國內投資，進而穩健國內財政。 本研究利用財政部國稅局的實際課徵資料，並輔以美國、南韓、日本等國之稅制改革經驗為借鏡，分別就遺產及贈與稅之稅收變動、稽徵成本、違章漏稅等多個面向，分析遺贈稅修正後是否收得其效及其對稅賦之影響。研究結果發現，除稽徵效率有待改善外，我國遺贈稅稅賦收入於修法後並未有重大改變，主要係因海外資金實有回流，使得稅率在大幅降低的情形下，稅基並未受到侵蝕，顯見該次修法係有符合最初的預期及社會之期待。 / Facing with several unfavorable factors such as economic downturn, budget deficits, and enormous social welfare expenditures, Taiwanese government decided to lead a reform of current tax system by dropping the highest marginal tax rate of estate and gift tax from 50% to single tax rate of 10% and raising the exemption. The main purpose of this amendment is to attract foreign capitals, stimulate domestic consumptions and investments, and ultimately revitalize the economy and stabilize domestic finance. This study examines the effect of dropping estate and gift tax rate. Based on actual imposition data collected from Ministry of Finance, and experiences of United States, South Korea, Japan and other countries. I find that except for the process of tax collection is not efficient as expected, there is no significant change of tax revenue after amendment of estate and gift tax law, the reason is that the inflow of overseas funds increases the tax base. Overall, the reform of estate and gift tax does meet the initial expectation.

在經濟學理上，雖有遺產及贈與稅課徵之理論基礎，但不同學者間並未有一致之共識；反映在稅政實務上，各國對於遺產及贈與稅的態度亦有不同，導致稅制或稅率的差異性極大。多數學者專家咸認為，遺產及贈與行為之決策動機難以窺見，因而導致理論或實務之歧異，無法經由資料的檢驗而釐清。再者，部份文獻雖論及各種遺產及贈與行為之決策動機，但仍多以贈與稅之存在係為補遺產稅之不足，而將遺產及贈與兩者混為一談。本研究指出，贈與行為之本質與遺產未盡相同，兩者之決策動機實有所別，稅制設計理當適度反應遺產及贈與行為的差異。本研究透過財政部財政資訊中心之統計資料，分析我國2001年至2014年間，遺產及贈與行為之決策動機，並藉由2009年遺產及贈與稅制的改革更張，檢視稅制對於遺產及贈與動機之行為誘因所造成的影響。