This Journal Economic Committee report does a good job of concisely explaining the progressive nature of the United States’ income tax system. The report contains this classic observation:

Collectively, the bottom 40% of earners thus pays little or nothing in income taxes. (Like all taxpayers, however, they do face the time, frustration, and monetary costs of preparing their taxes and complying with the complex tax code.)

While I have no problem with the progressive nature of the American tax system, the complexity of the system continues to be one of those outrageous aspects of American life that seems impervious to change. The Republicans occasionally talk about tax simplification, but then do nothing meaningful about it. The Democrats don’t even talk about it. Granted, the politics of simplifying the American income tax system is fraught with interest group obstacles. However, there are few political initiatives that would do more to improve Americans’ perception of their government than income tax simplification.
Meanwhile, Penn psychology professor Jonathon Baron and USC professor Edward J. McCaffery have published “Masking Redistribution (or its Absence)”, the abstract of which provides as follows:

Research has shown that people vary widely in their support or opposition to progressive taxation. We argue here that the perception of progressiveness itself is affected by the nature of the tax system and by the way it is framed, or presented. Experiments conducted over the World-Wide Web and using within-subject design demonstrate that subjects suffer from a range of heuristics and biases in understanding and supporting progressive or redistributive taxation. After reviewing some prior results, we report three new studies. Two of them indicate that people do not sufficiently appreciate the reduction of progressiveness that results from the use of tax deductions to partly reimburse private expenditures. The third indicates that people do not fully appreciate the reduction in progressiveness that results from cuts in government services.

Hat tip to the Law and Economics blog for the link to this article.