You’re moving the goalposts. The point is the tax bill, not “ability to pay per person.” On 100k total, MFJ owes thousands less in federal income tax than a sin

You’re moving the goalposts. The point is the tax bill, not “ability to pay per person.” On 100k total, MFJ owes thousands less in federal income tax than a single filer at 100k because the standard deduction and brackets are basically doubled. That’s exactly why marriage is usually a bonus at moderate incomes. The “marriage penalty” shows up mainly when both spouses have high, similar incomes/phaseouts, not in the $100k total case.