ABSTRACT
In his influential book, The Wealth of Nations, Adam Smith stated that a good tax system is one which meets the four criteria of equity, fairness, simplicity and certainty (1776: 452). He added (ibid) that it would be preferable that a tax system should have a great deal of inequity, rather than a little uncertainty:
The certainty of what each individual ought to pay is, in taxation, a matter of so great importance, that a very considerable degree of inequality, it appears, I believe, from the experience of all nations, is not so great an evil as a very small degree of uncertainty.
