In a progressive tax system, what typically happens to the MRT as income increases?

In a progressive tax system, the marginal tax rate (MRT) generally increases as an individual's income rises. This feature is designed to ensure that those who earn more contribute a larger percentage of their income in taxes compared to those with lower incomes. The rationale behind this system is grounded in the principle of vertical equity, which suggests that individuals with a greater ability to pay should shoulder a larger tax burden.

As income increases, tax brackets are structured so that higher rates apply to higher portions of income. For example, a person may pay a lower tax rate on the first portion of their income, but as they earn more, subsequent income is taxed at higher rates. This design serves to redistribute wealth and reduce income inequality, since it imposes relatively higher tax obligations on wealthier individuals.

In contrast, other options suggesting that the MRT decreases, remains constant, or fluctuates significantly do not accurately reflect how progressive tax systems are intended to function. In a well-structured progressive system, MRT increases align with the idea that higher-income earners contribute more, thereby reinforcing the effectiveness of the tax system in addressing income disparities within the economy.