HELP. me so the following question.

The budget constraint we considered thus far assumes only lump-sum taxes. In reality, lump-sum taxation is used very rarely. One of the reasons is that people are not identical and so the requirement that all people pay the same amount is not feasible. (Some people earn nothing and so are not able to pay any positive amount.) An alternative policy is a proportional labor income tax, where taxes are equal to a fixed fraction t, 0