Contrapeso.info ha publicado diversas columnas en favor del impuesto parejo o flat tax. Una nueva publicación del IMF arroja luz empírica sobre un tema complicado. Dice el estudio lo siguiente:
A notable and troubling feature of discussion of the flat tax is that it has been marked more by rhetoric and assertion than by analysis and evidence. The purpose of this paper is to provide a broad review of the lessons of principle and experience on the impact of the ”flat tax” (having first discussed what exactly it is—and is not). For it has now been in place in several countries long enough for serious evaluation to at least begin.
Much of the enthusiasm of advocates of the flat tax, of course, seems to relate at least as much to tax cuts, particularly in the upper part of the income distribution, as to flatness per se. While it is impossible to consider the effects of flatness without also addressing the impact of rate changes—moving to a flat tax necessarily changes the level of taxation applied to some groups—the focus in the paper is on flatness, since it is this that is the distinctive and novel feature of the reforms at issue.
The ”flat taxes” adopted in recent years differ widely. The first wave of flat taxes, for example, typically set the single rate at the highest of the pre-reform marginal tax rates; the second typically set it at the lowest. Even among the second wave reforms, some applied the same rate to corporate earnings, while others did not. Several, like the Slovak Republic, significantly increased the personal allowance; Georgia eliminated it altogether.
This diversity of design—plus variety too in the nature and extent of accompanying reforms to social contributions and benefits, and in levels of indirect taxation—precludes simple generalizations. The lessons that can be drawn are limited too by the relative paucity of careful empirical analysis: except for Russia and the Slovak Republic, there seems to be no reform analyses based on household-level data. There is an evident need for studies in other flat tax countries along similar lines.
El tema es obviamente complejo. El estudio completo puede ser encontrado aquí, un documento en PDF.