Proportionate Principle:
In order to satisfy the idea of justice in taxation, the principle of proportionate in taxation. These economists were of the opinion that if taxes are levied in proportion to the incomes of the individuals, it will extract equal sacrifice. The modern economists, however, differ with this view. They assert that when income increases, the marginal utility of income decreases. The equality of sacrifice can only be achieved if the persons with high incomes are taxed at higher rates and those with low income at lower rates. They favor progressive system of taxation, in all modern tax systems.