Check the corresponding page in the Policy wiki:
Regarding taxes, what general policies do you favor?
Generally speaking, we believe that people's labor should not be taxed at all. Instead, wherever practical, behaviour that is harmful to the society (like creating pollution) should be taxed.
To the extent that there is an income tax, we prefer it to be fairly progressive, with the rich being taxed more heavily than the poor. There should be no tax on incomes below the mean. Government revenues should be compensated in upper brackets.