Migration and optimal income taxes

The issue addressed in this paper is the optimal taxation of incomes earned in the home economy, and of incomes earned abroad, when people can migrate. As a preliminary, the optimal taxation of home incomes when there is migration and no taxation of foreign incomes, is discussed. Then in a more general setting, we deal with optimal taxation of different kinds of labour when another kind of labour is not taxable, and show how this bears on the taxation of foreign incomes. The last sections of the paper analyse a simple model in which people choose between taxable labour at home, taxable labour abroad, and untaxable labour. A condition is found implying that the optimal tax on foreign income is higher than on the home income of a person of equal utility.