I don't like how they lump the entire bottom 50% into a single category. The IRS has slightly more granular data, and the most recent information I can find is from tax year 2016:
LINK
It's pretty much impossible to calculate the difference between someone's marginal rate and what their actual tax rate without knowing their AGI. But this is as good as we can get.
I find the line showing percent of AGI subject to reduced tax rate (long-term capital gains and dividends) to be pretty illuminating. The highest income bracket is getting more than 50% of their income taxed at a reduced rate,
and the rest is probably in a tax-advantaged pass-through entity. Many of the bottom 50% do get tax credits, but they do not have access to these tax subsidies available to the higher income brackets.
Total revenue on bottom 50% (defined as <$50,000 per your link):
78,659 million (before tax credits)
-15,790 million (after tax credits)
Average* income subject to reduced tax rate: 0.9% (range: 1-1.3%)
Total tax revenue on top 1% (defined as >$500,000 per twofbyc's link):
527,721 million
Average* income subject to reduced tax rate: 27.3% (range: 12.5-53.7%)
* note that these are super rough estimates because I simply averaged the categories without accounting for the relative populations within each. Only on my first cup of coffee here.
Even if you eliminated the tax credits, there's just not much money you can squeeze out of the bottom 50%. On the other hand, I do wonder what this spreadsheet would look like if capital gains were taxed as ordinary income, and if LLC loophopes (including the new ones added by the GOP tax bill) were closed.
