The chart describes a

tax system

In this tax system, higher-income earners pay a (n)

proportion compared to lower-income earners.

- Proportional

equal

Explanation:

The given chart system discusses a 'proportional' tax system in which a similar rate of interest is charged across all the income-groups in the economy. The rate of tax is fixed by the government that needs to be paid by each taxpayer equally in proportion to their income. For example, a person earning $100,000 would pay $10000 as the tax if tax rate is 10% while one who earns $10000 would pay $1000 as the tax. Thus, higher-income earners pay an equal proportion in comparison to the low-income earners.