Uhhh, yes it's exactly like that, regardless of what is getting taxed.
Let's say today I make $24,900/yr. That puts me at the edge of the 20th percentile for 2017. The average effective tax rate for people of my income was -4.7% (or a tax of -$1170)[0]. You're suggesting increasing my taxes to 15%, taking $4905 out of my pocket as compared to today. Now, since I make next to nothing, pretty much everything I make is going to rent, food, and just generally getting by, and I have nearly $5k less real money (or ~20% of my income!!!) in my bank account to make that happen.
Hah. You are making the case that a flat tax is regressive because current income taxes are progressive. So moving from progressive to flat is regressive.
Its a tautological affirmation on progressive taxes being progressive. A flat tax would make a $24,900 pay $3,735, and if you made $249,000 you would pay $3735, your taxes increase just as proportional to your income. Its just..flat.
After criticizing my argument that looking at spending of taxes is necessary to argue if its progressive or regressive, you now propose an argument that would make progressive taxes also regressive unless they are enough to compensate the utilitarian value of how the poorer and the richer spend their own wealth.
The utilitarian argument is for me one of the most practical and also one of the most scary. Are you ready to exploit the poor if it were proven that it was economically profitable to do so? I digress. My point is that seeing flat taxes as regressive is either false or inconclusive, regardless of the desire of being flat, regressive or progressive in taxation.
Let's say today I make $24,900/yr. That puts me at the edge of the 20th percentile for 2017. The average effective tax rate for people of my income was -4.7% (or a tax of -$1170)[0]. You're suggesting increasing my taxes to 15%, taking $4905 out of my pocket as compared to today. Now, since I make next to nothing, pretty much everything I make is going to rent, food, and just generally getting by, and I have nearly $5k less real money (or ~20% of my income!!!) in my bank account to make that happen.
[0] - http://www.taxpolicycenter.org/model-estimates/baseline-aver...