your comment makes no sense...
you wrote this...
Average incomes rose from 63,000 to 74,000.
On this incremental increase in incomes, 40% tax was paid. (the extra 4,000 that the article cites)
either you got that wrong or you are the one who does not understand averages or your recent comment makes no sense.
Average income means total income / total number of tax paying entities.
If a few rich people have massive income increases that will increase the numerator without increasing the denominator. Those rich people pay marginal rates of 40percent.
This has nothing to do with a family earning 63000 in 2013 and 74000 in 2016.
Further to compare the effective tax rates: in 2013 Americans paid approx 15percent in ALL taxes and in 2016 17percent in ALL taxes. Does that seem unreasonable?
i don't blame you for not applying any critical thinking here. Your fake news article quoted the BLS site so that they could claim they used non-partisan data but they twisted it so much they deliberately didn't link to the report that they used.