A note on the optimum income tax

This paper analyzes the optimum utilitarian income tax, with special attention given to the characterization of the lower end of the optimum tax function, in the case when the least qualified individuals do not work. Moreover, the positivity of the marginal tax rate throughout is shown to be a consequence of the desirability of redistribution of income or leisure, given the self-selection constraints and preferences fulfilling agent monotonicity and non-inferiority of leisure.