an amount equal to about 5% of the GDP
insignificant then. Your class certainly should be paying about double your current rate.
At least until such time as you harvest your expectancy.
http://www.washingtonpost.com/blogs/wonkblog/wp/2012/09/19/heres-why-the-47-percent-argument-is-an-abuse-of-tax-data/The average tax rate overall, including federal, state, and local taxes, is around 30% for the top 2 QUARTILES of income. So if you're in the top "40%", which might be "your class", then doubling that rate would be 60% of your income. That is quite excessive.