綠色租稅改革及所得分配之一般均衡分析

綠色租稅改革是整合一國稅制及解決環境問題的一項重要嘗試，惟此一改革是否有機會達到雙重紅利或是多重紅利的效果，更是政策制定單位及普羅大眾所密切關心的議題。為評估我國施行綠色租稅改革所可能帶來的衝擊效果，本研究建構一以社會會計矩陣 (SAM) 為基礎，並涵括詳細所得分配機制之靜態可計算一般均衡 (CGE) 模型，模擬幾種綠色租稅改革方案對我國環境、經濟及所得分配的影響。回應綠色租稅改革的內涵及特性，本研究模型針對不同課稅標的區分從量或從價之課徵機制，且為忠實評估稅制改革對所得分配的影響，也將家計單位區分為十個所得階層，並以主計總處「家庭收支調查報告」之詳細原始資料，整理出各所得階層家庭之不同職類勞動來自不同產業部門之薪資所得、各所得階層來自不同產業部門之資本及其他所得，以及各所得階層消費各產業部門產品之支出及其他支出等。本研究模擬之綠色租稅改革方案主要係以維持稅收中立為設計基準，新增稅制為碳稅或能源稅，並搭配取消貨物稅或增加政府支出、消費支出、降低所得稅等。模擬結果顯示，各情境均具二氧化碳減量之第一重紅利效果，惟碳稅的設計是以能源產品隱含之碳含量為稅基，因此減碳效果較為顯著，而能源稅之設計因係對不同能源產品課以不同稅額，因此二氧化碳減量效果相對略差一些。在是否能夠改善整體租稅效率之第二重紅利方面，則以等比例降低綜合所得稅稅率及取消貨物稅之配套較具效果，可增加整體經濟福利及改善實質國民生產毛額。其中，課徵能源稅同時取消貨物稅的收入循環效果大於稅賦交互效果，可達到強定義之雙重紅利；至於課徵碳稅並同時取消貨物稅或降低綜合所得稅稅率的收入循環效果雖然小於稅賦交互效果，但仍具弱定義之雙重紅利。最後，對第三重紅利之所得分配效果而言，各模擬情境之吉尼係數數值變動情況顯示，課徵碳稅或能源稅並同時取消貨物稅將具有改善所得分配的第三重紅利效果。

關鍵字

社會會計矩陣；可計算一般均衡模型；綠色租稅改革；雙重紅利；所得分配

並列摘要

Green tax reform has been an endeavor toward integrating taxation systems and resolving environmental problems by many economies in recent years. However, whether this reform could lead to a result of double dividend remains an unanswered question to most of the policy makers and the general public. This study aims to simulate the effects of green tax reform for Taiwan by using a SAM-based CGE model specializing on income distribution mechanisms. The model constructed also takes into account the characteristics of green tax reform and specifies corresponding taxing mechanisms for different taxation systems. Detailed household income and expenditure data fitting to the model structure are compiled from the raw household income and expenditure survey data collected by the DGBAS of Executive Yuan. Simulation scenarios of this study are designed in such a way that tax revenue be remained neutral. We simulate either a carbon tax or an energy tax be levied, with a corresponding reduction of commodity tax or household income tax. Separate scenarios of taxing carbon emissions or energy usage in combination of increasing government expenditure are also performed. Our results show that both carbon and energy tax schemes, when accompanied by a reduction of commodity tax will generate not only double but also triple dividend effects to the economy. Keywords: Social accounting matrix, computable general equilibrium model, green tax reform, double dividend, income distribution