1. There are more taxes other than income tax. Corporate income tax for one. Estate taxes, financial speculation tax, VAT - each world state and its own system.

1. There are more taxes other than income tax. Corporate income tax for one. Estate taxes, financial speculation tax, VAT - each world state and its own system. 2. Even regarding income tax - in most world states, tax is not flat, and most workers pay little income tax anyway (sometimes even 0, if there's a threshold for non-zero tax rate, or tax credits for various social situations etc.) So not regressive. Also, like other commenters mention - if you don't attend university, your children, or other relatives and friends, might be. Plus, we all need the higher education system to function, for modern society to function, so it makes sense that we contribute to it through some mechanism.