I wouldn't call it a myth. High income earners both then and now have a lot of ways to avoid paying tax, so they don't pay nearly as much as the top marginal rate. It's also true that the top marginal rate used to be much higher.
> Meanwhile, the proportion of taxes paid by the top quintile earners has increased from 55% in 1980 to 70% by 2013.
Isn't this exactly what you would expect with growing income & wealth inequality, so long as your tax system maintains some aspect of progressive taxation.
I'm not claiming I know what is actually happening in the US, it's complicated and I haven't spent enough time looking at it to be confident.
However, it's true that if there is a) an increase in total income that b) is entirely captured by a small percentage of people, then naturally their share of the total income tax paid will increase and everyone else's will decrease as a fraction unless the system is regressive in some way.
"Progressive" here doesn't mean higher earners pay more in aggregate, it means (by definition) that their marginal rates are higher that people with lower income.
Even if you taxed them to the bone it wouldn't be enough so you're going to need to tax the bulk of the commerce instead of just the residuals after it falls into their relatively idle hands.
> Meanwhile, the proportion of taxes paid by the top quintile earners has increased from 55% in 1980 to 70% by 2013.
Isn't this exactly what you would expect with growing income & wealth inequality, so long as your tax system maintains some aspect of progressive taxation.