What type of tax structure requires all income earners to pay the same proportion of their income?

The correct answer is a proportional tax structure. In a proportional tax system, every income earner pays the same percentage of their income, regardless of how much they earn. This means that if someone makes $30,000 and pays 10%, they would pay $3,000, while someone making $100,000 would also pay 10%, resulting in $10,000 in taxes. This structure is often viewed as fair because the tax burden does not vary with income levels; everyone contributes the same proportion.

This contrasts with a progressive tax system, where higher-income earners pay a larger percentage of their income in taxes. A regressive tax, on the other hand, takes a larger percentage from lower-income earners, which can lead to an increased tax burden relative to their income. A flat tax generally refers to a single tax rate applied to all taxpayers, which in many contexts functions similarly to a proportional tax, but may not specifically imply that the same proportion is applied across all income levels. Overall, the key characteristic of a proportional tax is the equal tax rate applied to income, making it a distinct and clear choice.