Income Tax Progressivity and Income Inequality

Economists justify fair taxation in different ways. one of these approaches is the "utilitarian" approach that argues the amount of tax levied should be based on additional utility that a person may derive from consumption of valuable goods. But, the level of marginal utility for owning money differ from other commodities so that it is inapplicable. On the other hand, the assignments of specific tax should be associated with the benefits that a taxpayer drive from public institutes is also injustice as it cannot assess all individuals those who may not stand at the door of government offices for that tax period. The remaining is the "ability to pay" principle, which importantly lies on the amount of taxable income that the taxpayer earn in the tax period.It is true that individuals that derive similar income should bear similar tax burden horizontal equity, and those who earn more should bear more tax burden. Nonetheless, it is not an easy task to measure the capacity of individuals only on the amount of their earnings as it does not account the number of dependents that the taxpayer may support.