Progressive taxation is viewed as more fair by more people that flat taxation. You're using "income" as your input variable to calculate "fairness", but you co

Progressive taxation is viewed as more fair by more people that flat taxation. You're using "income" as your input variable to calculate "fairness", but you could just as easily use "disposable income". Someone making $25,000 per year might have a disposable income of $0. Asking this person to kick in $5000 seems ludicrous. I honestly don't know how you could assess fairness without looking at ability-to-pay: (income) - (basic survival needs) = (money leftover you can potentially contribute to the government) This is obvious, fair, and is why most nations have progressive taxation structures.