A tributação das grandes fortunas

: entre a progressividade, a justiça fiscal e o confisco em sede de IRS

Abstract

The present Dissertation focuses on the taxation of large fortunes from the perspective of personal income taxation, a relevant topic that is widely discussed by numerous countries, particularly due to concerns on economic efficiency and on the sustainability of public finances. Starting with an analysis of the current model of the Personal Income TAX (PIT) and its historical evolution, we explore that main principles that shape this tax, seeking to understand how its implementation required the establishment of maximum limits in order to preserve the taxpayers’ rights, namely those that are constitutionally recognized. We also reflect on the reasons that can be abstractly accepted as justifications for an increase in the current tax rates or in the progressivity of the PIT brackets in order to tax the so-called large fortunes, which we conclude that, in general, do not exist in Portugal. Arguments in favor of this tax burden’s increase are related to the sustainability of public finances, to the equality and to the tax justice. We then deconstruct the aforementioned arguments, reflecting on two core issues. On one hand, we examine the risk of confiscatory taxation, studying, with reference to both national and international doctrine and jurisprudence, how this issue has been raised. On the other hand, we reflect on the relationship between the increase in the tax burden and the collection of (tax) revenues by the Portuguese state, considering Laffer’s insights. Finally, we provoke questions and reflections on the current model and what its future may hold, particularly analyzing the national landscape.

Date of Award	27 Jun 2025
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Tomás Tavares (Supervisor)