Just how big a share? How much is enough?
It is safe to say that if by some magic all the world's wealth were evenly and equally distributed and everyone had equal wealth, within two years or five years, maximum, everyone who had been poor before the re-distribution would be poor again, and everyone who had been rich would be rich again.
Quite a lot of bigotry towards the poor in that statement.
How much is enough... well lets say if I have to pay 17% of my earnings then so should they. I cannot afford $500k to open offshore, tax free accounts nor can I invest a couple of hundred grand each year for more tax free earnings. Just tax everyone on everything they earn above the poverty line equally with no deductions available. Same goes for corporations, taxed on their annual earnings with no deductions. You then have a level playing field for everyone. This would increase our tax revenues overall by billions every year.
It is not so much the rate of taxation that is the big problem it is the fact that the best deductions off taxable income are only available to the rich and to corporations. That is where the fix needs to be, once it becomes equitable the rate applied could probably drop to about 12% and still put billions more into the government purse.