It's true that a flat tax rate results in the same disutility for everyone, and if your goal is perfect equality of disutility, it seems correct. However, as a

It's true that a flat tax rate results in the same disutility for everyone, and if your goal is perfect equality of disutility, it seems correct. However, as a counterpoint, following the same theory, preferentially taxing the rich concentrates the disutility in a smaller group: if you add up all the utility values in a progressive tax system you get a higher total result, though the individual results vary. EDIT: e.g. https://i.imgur.com/DppEKTT.png https://i.imgur.com/DppEKTT.png