臺灣菸品市場之租稅負擔是個很奇特之現象，當臺灣政府對香菸產品課稅時，菸商會將租稅完全轉嫁給消費者，即便消費者之需求是有彈性的。本文為探討此原因，以Milgrom and Roberts之利潤目標模型為基礎，建立一個廠商追求利潤目標之模型來解釋，當菸商面臨政府課稅時，是否會將租稅百分之百轉嫁給消費者。由此模型推論出，若菸商欲維持市場之獨占或寡占地位時，便會追求較低之利潤目標，使潛在競爭者相信菸品市場利潤不大，此時潛在競爭者便不會進入菸品市場中與現有之菸商競爭。 本文設定利潤模型後，便以此利潤模型進行比較靜態分析，本文假設當菸商欲維持在市場之獨占或寡占地位時，於政府課徵從量稅後，會如何轉嫁租稅給消費者，並分別由價格及數量為切入點分析。經過比較分析後的結果可得知，只要菸商之目標為持續保有獨占或寡占之地位，而非追求利潤極大化時，租稅的完全轉嫁即會存在，即使消費者需求是有彈性的，消費者將會面對一個稅額百分之百增加的供給價格。 / The tax burden of cigarette products in the Taiwanese market baffles many researchers in public finance. Despite that the demand of cigarette products is elastic, when the tax rate of cigarette products increases, cigarette manufacturers, with no exception, raise the prices accordingly, and therefore, the increased taxes are entirely shifted to consumers. This is very different from the traditional idea of tax incidence based on elasticity. In order to figure out the reason, this paper uses the framework of the limit pricing model of Milgrom and Roberts (1982) with the assumption of target profit to establish an economic reasoning of why the tax hikes in the cigarette products are one hundred percent shifted to consumers. This model infers that when cigarette manufacturers have entry deterrence in mind, they tend to pursue a lower profit target to keep potential competitors away. Given the framework and basic assumption from above, comparative statics of tax increases are done for both quantity and pricing games. The results suggest that when cigarette manufacturers are facing an increase in the unit tax rate of their products, it is typical that the incidence of the increased tax been no less than one hundred percent forward-shifted to consumers. The traditional theory of tax incidence by elasticity under the profit maximization firms does not apply here. The economic intuition is that in order to thwart entry, existing firms use the complete forward shifting of the tax increase as a bad signal of the profitability of the market to potential competitors.

本論文的研究目的，主要是從理論的探討與實證的研究出發，評估國內以香菸稅做為反菸工具時的可行性與適當性。 　　由於近些年來，在反菸團體大力地宣導吸菸有害健康的警訊之下，香菸似乎被貼上了罪惡的標籤，除了對人體健康有直接的危害之外，吸菸行為在醫療資源上的浪費與經濟成本上的損失更是不容忽視的問題。因此，除了一般性的租稅課徵之外，許多的學者都主張應再對香菸課以重稅，以期減少社會大眾的香菸消費量。不過在另一方面，亦有學者指出，目前在探討吸菸行為所引起的疾病成本或外部成本時，都忽略了外在環境的改變與其他因素的影響，而使得菸害成本有被高估的可能，因此反對重課香菸稅。其次，由於香菸稅基本上是屬於銷售稅的性質，因此在課稅之後，勢必會對經濟體系造成若干程度的影響，所以本文在理論探討的部分，除了分析香菸稅的理論依據之外，亦將課稅之後所可能產生的經濟效果做一分析與整理。 　　而在實證研究的部分，本文則利用主計處「個人所得分配調查報告」的原始電腦資料，以橫斷面與虛擬長期追蹤模型資料(pseudo panel data)分別估計國內的香菸需求函數。根據研究的結果顯示，國內的香菸價格彈性在-1.35~-1.56之間，表示當價格上升10%之後，香菸的消費量將減少13.5%~15.6%，可見以香菸稅做為反菸工具的效果相當地顯著。 　　總之，若政府的政策是以維護國民的健康而欲減少國內的香菸消費時，透過對香菸課稅的方式確實能達到「以價制量」的既定目標，而且其政策的效果相當地顯著。不過值得注意的是，香菸稅的課徵，雖然可達成上述的反菸政策效果，但卻也會造成租稅累退與超額負擔的發生；甚至由於菸害成本的高估現象，而使得香菸稅率有偏高的趨劫。因此，政府在訂定香菸稅的政策時，除了考慮價格效果之外，同時也必須平衡其所產生的經濟影響，如此才能訂出適當的稅率以充分反映與矯正外部成本的發生。因此，一個最適香菸稅率的決定，則是未來所必須面對的問題了。

This diploma paper deals with the tax incidence of cigarette tax in the period of the changes in rates of this duty in the Czech Republic. The main aim of this paper is to find out how the cigarette tax shifts on consumer and producer. Moving of tax burden was found out thanks to investigation of cigarette prices in the period from September 2007 to February 2008. The amount of tax was calculated from these prices. Various periods were compared and results were closely analysed. Fiscal and educative function of cigarette tax was monitored in this paper too. Educative function was found out by the help of trend in the number of smokers and their cigarettes consumption, whilst fiscal function was demonstrated by trend of payment excise duties. At the close of diploma paper are mentioned also tax avoidances of the excise duty on cigarettes, that are large problem all the time not only in the Czech Republic.