The Effectiveness of the Principle of Tax Capacity under the Simples Nacional Regime: An Analysis from the Perspective of Law and Economics and Fundamental Rights.
Simples Nacional; Fundamental rights; Law and Economics; Ability to pay; Transaction costs.
Taxation is an essential instrument for the functioning of the State and must comply with constitutional principles, especially the principle of ability to pay. This thesis analyzes the effectiveness of this principle within the framework of the Simples Nacional tax regime, in light of Law and Economics and fundamental tax rights. The study adopts an interdisciplinary approach, combining bibliographic research, documentary analysis, and systematic interpretation of legislation, case law, and empirical data. It concludes that, although Simples Nacional represents progress in tax simplification, it still presents distortions that undermine fiscal justice, such as the disproportionality of the tax burden in relation to the taxpayers’ real contributive capacity, excessive complexity, and high transaction costs. The research finds that, in practice, the regime does not fully respect the existential minimum and may result in confiscatory effects. The study proposes an institutional redesign of Simples Nacional, with greater progressivity, respect for taxpayers’ financial capacity, and reduction of compliance costs, in order to align the regime with the constitutional foundations of fiscal justice, free enterprise, and support for micro and small enterprises.