Consumption taxes are not a major topic in US politics because they are rarely proposed, especially on the federal level. When consumption taxes are brought up, the discussion tends to devolve into a debate about whether they are regressive or not. As with most progressivity or regressivity debates, this one tends to be muddled and confused because we don’t actually use those two words consistently across different policy topics.

In the context of tax policy, the way you determine whether a tax is progressive or regressive is by adding up how much tax each person is being charged and then dividing that amount by their income. If the resulting percentages go up as incomes go up, then that is considered a progressive tax. If the percentages go down as incomes go up, then that is considered a regressive tax. If the percentages are the same across the income distribution, then that is considered a flat tax.

In the context of spending policy, the way you determine whether a spending program is progressive or regressive is by adding up how much money each person gets from the program. You do not divide that amount by income. Instead, you just look directly at the dollar amounts. If those amounts go up as incomes go up, then that is considered a regressive program. If those amounts go down as incomes go up, then that is considered a progressive program. If the amounts are the same across the income distribution, then that is considered a flat benefit.