Which type of equity is associated with taxpayers having the same income level paying the same taxes?

The correct answer is associated with the principle of horizontal equity, which states that individuals with similar income levels should face similar tax obligations. This principle is grounded in the idea of fairness in taxation; if two taxpayers have the same income, they ought to contribute the same amount in taxes to ensure an equitable system.

This concept is fundamental in discussions of tax justice, as it highlights the expectation that the tax burden is distributed uniformly among those in similar economic circumstances, thus promoting consistency and fairness in the tax code.

In contrast, other concepts like vertical equity focus on the idea that those with higher incomes should pay more in taxes than those with lower incomes, which does not pertain to taxpayers with the same income. Progressive and regressive equity refer to tax structures where rates vary with income levels, which also diverges from the principle of treating similarly situated taxpayers the same.