Maybe at this juncture, when Congress is beginning to talk about what to do about the sunsetting Bush tax provisions, it's an appropriate time to remind ourselves about our historic commitment to progressivity in our tax system. A good source for thinking about this is an article by Tom Piketty and Emmanuel Saez, Progressive is the U.S. Federal Tax System? A Historical and International Perspective, 21 J. Econ. Perspectives 3 (2007).
What they show by looking at income and taxes over the period from 1960 to 2004 is revealing. While our system remains progressive to some extent, the progressivity has declined significantly. This is primarily, they say, because of the cuts in the corporate tax and the estate tax--taxes that impact the very wealthiest more than others because of their high ownership of financial assets. Our concept of distributive justice has always demanded that we should determine the tax burden based on individuals' relative abilities to pay--that means that those with lots more should pay proportionately more of their income, since those with very little need all of their income just to meet daily needs, and those with considerable wealth won't even notice whether they have another few dollars or not.
The decades since Reagan took office have taken a huge toll on that sense of shared commitment. Fueled by a religious-like belief in the mathematically elegant but unrealistic assumptions of the "free market" economists from the Chicago School (see Yves Smith's book, Econned, for a good take-down of the freshwater economists), the GOP in Congress passed huge tax cuts for the wealthy accompanied by increasingly heavy payroll taxes for others at the same time that spending continued apace--in fact, Reagan, Bush1 and Bush2 all greatly increased the military budgets and the Bushes embarked on wars of choice that imposed significant budgetary demands. The wealthy have fought for laws that favor them--deregulation, zero capital gains taxation, lower corporate taxes, the ability to offshore businesses and assets freely, privatization of social security and other programs (that would put more dollars under direct control of investment bankers and insurers), and lowering of individual tax rates and provisions that phased out deductions for the wealthy (like the phase out of the itemized deduction, which was repealed under Bush, etc.).
There are some really great graphs in the article--so look at it rather than just reading these excerpts. But if you only have time for excerpts, here are some key ideas.
Progressivity of the overall tax code has unambiguously declined in the United States and in the United Kingdom. The average share of income paid by those at the very top of the income distribution has dropped substantially. Id. at 21
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Large reductions in tax progressivity since the 1960s took place primarily during two periods: the Reagan presidency in the 1980s and the Bush administration in the early 2000s. The only significant increase in tax progressivity since 1960 took place in the early 1990s during the first Clinton administration. Id. at 23
http://ataxingmatter.blogs.com/tax/2010/03/declining-progressivity-in-us-taxes.html