Simplicity
3.19 After equity, simplicity is perhaps the next most universally sought after of qualities in individual taxes and tax systems as a whole: like fairness it is a word that, in this context, points to a complex of ideas.
3.20 Two of these are explicitly stated in the Committee's terms of reference. A tax will be called simple, relatively to others, if for each dollar raised by it the cost of official administration is small, and if the ‘compliance costs’, the costs in money and effort of all kinds to the taxpayer, are also small. These two ideas are of course connected, and add up to much the same as the ancient canon of certainty. Both costs will be the less if assessor and assessed can each establish with certainty what is due: uncertainty entails the costs of consultation with experts and sometimes the yet greater costs of litigation. Both kinds of cost are increased, and certainty is endangered, when a tax, whether in the interests of equity or of efficiency, requires the drawing of fine distinctions between what is and what is not liable, and when these distinctions involve such uncertain ideas as ‘purpose’ or ‘value to the recipient’. Then the legal definitions get longer and longer and beyond the comprehension of those untrained in the law, and the relevant facts in particular cases become more and more disputable.
3.21. Two further aspects of simplicity require specific mention here. First, when (as is often unavoidable) a quite complex operation is needed before the administrators can make the assessment or the taxpayer can ascertain his liability, it is desirable that the tax be such that the taxpayer, for private purposes unconnected with tax, already needs to perform such operations. A tax on company income may be fairly regarded as a simple tax if the company already calculates its income or profits on the same or very similar basis. A tax on personal income is not a simple tax if it be so structured that many taxpayers who would not otherwise wish (or without hired help be able) to keep accounts at all, have to preserve many records and learn sophisticated accounting. The point, though obvious, is often forgotten.
3.22. A second observation is perhaps even more obvious and even more frequently forgotten. The fewer, per million dollars raised, are the individuals or organisations from whom tax is collected the simpler is a taxation system. The sheikdom that can raise all the revenue it requires (and maybe much more) from a single tax on a single oil company has what is unquestionably the simplest tax system of all.