What will happen with this taxation is that if everybody makes the same income, then everybody pays 50% in tax. If some rich dude is making a lot more money then everybody else, they will lower the tax for everybody else while paying a lot more them selves. At some point (say 3 standard deviations above the mean) you end up getting less after taxes then had your income been lower (say 2 SD above), in other words, the limit is 100% tax for extremely high incomes (and 0% for extremely low incomes). That is, I favor a system that has maximum income, and you are actively punished for making more.