Sales Tax
What is Sales Tax?
A sales tax is a tax on goods and services collected at the point of sale as a percentage of the price.
It is generally considered regressive because lower-income households spend a larger share of their income on taxed consumption. It is a major revenue source for U.S. state and local governments.
Sales Tax: a worked example
A state charges an 8% sales tax on taxable goods. Household A earns $40,000 and spends $37,500 of it on taxed purchases, paying 0.08 x $37,500 = $3,000 in tax, which is $3,000 / $40,000 = 7.5% of income. Household B earns $135,000 and spends $67,500 on taxed purchases, paying 0.08 x $67,500 = $5,400, which is $5,400 / $135,000 = 4.0% of income. The statutory rate is identical, yet the effective rate against income falls from 7.5% to 4.0% as income rises, and that falling pattern is exactly what regressive means. At the register the mechanics stay simple: a $50 item rings up at $50 x 1.08 = $54.00, and the seller forwards the $4.00 to the state.
The mistake students make with sales tax
Students compute the rate off the receipt total instead of the pre-tax price. An 8% tax on a $50 item shows $4.00 of tax and a $54.00 total, and dividing $4.00 by $54.00 returns 7.4%, which understates the rate actually applied. The mirror error runs backwards: handed a $54.00 total, students subtract 8% and get $49.68 instead of dividing by 1.08 to recover the $50 price. A sales tax is a percentage of the pre-tax price, so the pre-tax price belongs in the denominator both times.
Sales Tax questions
Why is a sales tax regressive if everyone pays the same rate?
Regressivity is judged against income, not against the price tag. A household spending 90% of its income on taxed goods hands over a much larger share of income than one that spends 50% and saves the rest, even though both face the identical statutory rate. Because the share of income saved tends to rise with income, the effective tax rate measured against income falls as income rises.
What is the difference between a sales tax and an excise tax?
A sales tax applies broadly across most retail purchases and is charged as a percentage of the price, making it an ad valorem tax. An excise tax targets one specific good such as fuel, tobacco, or airline tickets, and is usually a fixed amount per unit sold. On a graph the difference shows: an ad valorem tax rotates the supply curve, while a per-unit excise tax shifts it up by a constant amount.
Who really pays a sales tax, the buyer or the seller?
Statutory collection sits with the seller, but the economic burden splits according to relative elasticity. Whichever side of the market is more inelastic absorbs the larger share, because it has fewer alternatives. When demand is highly inelastic, most of the tax shows up as a higher price paid by buyers. When demand is elastic and supply is not, sellers swallow more of it through a lower net price received.
This is the live Supply and Demand sandbox. Drag the curves, or open the full version.
Related terms
Common comparisons
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