稅法一般反避稅條款的合憲性審查及改進

稅法一般反避稅條款落入憲法財產權與契約自由權的保護範圍，有介入憲法視閾關照之必要。財產權的社會義務理論可以為一般反避稅條款的合憲性提供學理支撐與觀念基礎。儘管如此，這一條款仍要接受合憲性的框架與邏輯檢視。一般反避稅條款建制應以基于納稅人平等權的量能課稅原則為主導理念，不宜過度宣示反避稅的國庫主義至上立場。在制度設計層面，基於法律保留原則、比例原則與平等原則的要求，現行一般反避稅條款立法亟待予以合憲性修補。在法律適用層面，應引入合憲性解釋方法與機制，對稅法規範予以合憲性解釋以貫徹憲法原則與精神，保障一般反避稅條款個案適用的合憲性。基於稅法與憲法的高度關聯，稅法學研究有向憲法學思維借鑒之必要，並應尋求與憲法學的學理和方法論溝通。

The General Anti-Avoidance Rule(GAAR) in the tax regime falls under the scope of “property rights and freedom of contracts” of the constitution and thus shall be examined from the constitutional perspective. The social obligations of property rights provide the theoretical and conceptual basis for the constitutionality of GAAR, which shall still be examined under the framework of constitution. The guiding principle to formulate the GAAR is the ability-to-pay doctrine, which is based on the equal rights of taxpayers, rather than the increase of revenue for the treasury. The principle of law reservation, the principle of proportionality and the principle of equality shall be taken into account during the revision of the existing GAAR. As for the legal application, constitutional interpretation shall be introduced, and the constitutional principle and spirit shall be taken into consideration on how to interpret tax provisions. Tax law scholars should introduce the theory and methodology of constitutional law into their studies.