If all purchases are subject to the same tax rate, the capitation standard itself is flat with less than income people paying extended bite as they consume more. While the fine on spending as a percentage of gross income may be regressive, the effective duty rates can be progressive on consumption due to exemptions or rebates. If a sales tax is to be related to income, then the unspent income can be treated as tax-deferred (spending savings at a later point in time), at which era it is taxed. Sales taxes often exclude frills or provide rebates in an effort to create progressive effects. In crowded locations, visit "necessary" items such as non-prepared food, clothing, or prescription drugs are exempt from sales tax to alleviate the burden on the poor.

A related type of tax is the value-added tax or VAT. It is a system in which all businesses remit taxes on their sales but they are also refunded the amount of VAT remitted by their suppliers. In augmentation to avoiding cascading, under VAT there is no must for dominion to determine which sales are taxable and which are not, since all sales--retail, comprehensive and intermediate--are taxed.