If average tax rates rise with income, we say the tax system is «progressive». (canadianbusiness.com)
Even if you're paying a lot of taxes now, you're talking marginal dollars when you look at current contribution, and average tax rate when making withdrawals. (money.stackexchange.com)
Look at the overall average tax rate of your expected retirement income - if you're expecting to pull out $ 100k a year, you're probably paying less than 20 % in average taxes, because the first third or so is taxed at a very low rate (0 or 15 %), assuming things don't change in our tax code. (money.stackexchange.com)