No, not all people would agree. It's coherent to think that a) government punishment should be the same for each recipient, b) we measure punishment (and thus i

No, not all people would agree. It's coherent to think that a) government punishment should be the same for each recipient, b) we measure punishment (and thus it's "sameness") in terms of pain, and c) financial penalties need to be indexed against wealth/income to inflict the same amount of pain. Sweden (I believe it is) in fact does this. ------ Regardless, yes as the OP says if you think it's fair to charge a flat fine, then surely it's fair to charge a flat fee. The point is relative and thus holds whether you define fine equitability in terms of amount paid or difficulty in making the payment.