"The data comes from a recent paper by Thomas Piketty, Emmanuel Saez, and Gabriel Zucman that attempts to account for all federal, state, and local taxes paid by different groups of Americans over the last 100 years"
But regardless, it was higher in 1950, almost 6 points higher.
And look at al the caveats...
1] Some of the distributional assumptions in the Piketty, Saez, and Zucman paper are questionable. In particular, the authors assume that the full burden of the corporate income tax falls on owners of capital, which may not be correct. However, the authors note that they “have tested a number of alternative tax incidence assumptions, and found only second-order effects.”
[3] It is worth noting that, per the Piketty, Saez, and Zucman data, the tax rates of the top 0.1 and 0.01 percent of taxpayers have dropped substantially since the 1950s. The average tax rate on the 0.1 percent highest-income Americans was 50.6 percent in the 1950s, compared to 39.8 percent today. The average tax rate on the top 0.01 percent was 55.3 percent in the 1950s, compared to 40.8 percent today.
[4] The data from Piketty, Saez, and Zucman is not divided among federal, state, and local taxes, so it is difficult to tell exactly how much the rich were paying in federal income taxes specifically during this period.