자료: Nicholas Kaldor, An Expenditure Tax
The case in equity for taxing people in accordance with what they consume rather than what they earn was succinctly 300 years ago by Hobbes. It was re-stated, on rather different grounds, just over one hundred years ago in the Principles of Political Economy by John Stuart Mill who argue the case (...) before the Select Committee on Income and Property Tax of 1861. Mill's advocacy was taken up by a row of distinguished economists like Marshall and Pigou in England, Irving Fisher in the U.S. and Luigi Einaudi in Italy. There can be few idea in the field of economics which are so revolutionary in their implications and yet can look back on so respectable an ancestry.
It is fair to add that the full implications of the case were unknown to the economists of earlier generations (...) until the experience of our own generation with heavily and steeply progressive income tax rates together with the general progress of theoretical understanding combined to bring sharply into focus considerations which were completely unsuspected in earlier discussions.
Since Mill's day our income tax system has introduced a broad differentiation in favor of 'industrial' incomes in the shape of earned income relief; it has also provided that wage and salary earners should be able to accumulate funds free of tax in connection with approved superannuation schemes. If one looked at the question therefore from Mill's point of view alone one would have to concede that the case for an expenditure tax, on grounds of equity, is not as strong now as it was (although on economic and incentive grounds, owing to a a 20-to-30 fold rise in the rates of taxation in the interval it is very much stronger).
But it fact neither Mill nor any of the other advocates did full justice to the case for an expenditure tax on grounds of equity--they did not even suspect it. This does not really rest on the element of 'double taxation' of savings involved in an income tax, but arises from more fundamental shortcomings of the 'income' as a measuring-rod of taxable capacity.
- The real inequities of the system arises not so much from the failure to exempt savings out of 'income', but the failure to tax as 'income' the spending power that is exercised through 'dis-savings'(or spending out of capital) or through capital profits or other receipts of various kinds.
- Since these non-taxable sources of spending power are not distributed at random, but are closely linked with the ownership of capital, taxation according to 'income' introduces a bias in favor o property owners whose taxable capacity is underrated relatively to those who derive their income from work.
- Moreover since taxable income from property can be converted into capital gains in numerous ways 'income' is not only a defective measure of taxable capacity but one whose relation to taxable capacity can be manipulated by certain classes of taxpayers.
- Thus Mill himself, having declared before the Select Committee that the only 'perfectly unexceptional and just principle of income tax' is to 'exempt all savings' [,] went on to say that the 'amount of saving cannot be got at in an individual case,' and all that a tax system could do in deference to the principle is to tax those incomes more leniently which can be presumed to give rise to more savings, since they are temporary in duration and precarious in character.
- Similarly Marshall, in suggesting that a graduated tax on personal expenditure is superior to all other forms of taxation, direct or indirect, described the tax as a 'Utopian goal', though he added that 'the way to this ideal perfection is difficult but it is more clearly marked than in regard to most Utopian goals'.
- Professor Pigou (...) referred to the impossibility of preventing dishonest citizens making a practice of 'saving in one year, thus escaping taxation, and secretly selling out and spending their savings in the next year'.
- Keynes (...) dismissed the Expenditure Tax in a sentence by saying that while the tax is 'perhaps theoretically sound, it is practically impossible'.
The early advocates of the expenditure tax generally based their case on the 'double taxation' of savings involved in the income tax. Though the adverse economic effects of the special discouragement to savings on 'thrift and enterprise' (as Mill put it) were never far removed from their minds, their main preoccupation lay elsewhere--in the inequality of a system which rates the ability to pay of a person who has reserve part of his current earnings against emergencies and for retirement no differently from that of a person whose income is derived from a safe and permanent source. In Mill's view the principle of taxing 'income'(including savings) confers a differential benefit on property owners as against those who derive their income from 'personal industry' and who cannot treat the whole of their incomes as 'spendable' as the capitalists can.
 Cf. the chapters on the Theory of Public Finance in Myrdal, Political Element in the Development of Economic Theory (1953) for a brilliant criticism of the doctrines of public finance in this respect.
Unless we set before ourselves the idea of what is perfectly just, we are unable to make any fair approximation to justice in the practical application. I should say that the first rule if the general rule of taxation, namely equality; that is to say taxation in proportion to means.
- If people's needs can be arranged in a descending scale of urgency [, it follows that] the less urgent [is] the need which a person is in a position to satisfy, the greater is his ability to pay tax relatively to another person whose `marginal satisfiable need` is at a higher point on the scale.
- Thus as between two men, one with ￡5,000 a year and one with ￡500 a year, the tax burden could not be said to be equitably distributed between the two unless the first man were called upon to pay a proportionately higher sum than the second.
- The case for progressive taxation rests on the political objective of the promotion of economic and social equality;
- and the `ideal` degree of progressiveness of taxation can only be thought of as the one which most closely reflects the prevailing social conception of equity (...)
- Failure to give effect to the social and political objectives which the tax system intends to serve is far more likely to arise as a result of an imperfect appreciation of the requirements of an equitable tax base, and of the choice of an inappropriate definition of `taxable income` than of an inappropriate definition of tax rates.
- Whereas a schedule of rates is easily comprehended, the same cannot be said of the basis on which income, in all its variety, is defined and assessed.
- `Means` carries a sense not just of `money`, but of money in relation to certain objective needs, obligations, commitmentsㅡa sense which can best be described as taking into account (and making allowance for) variations between individuals in the opportunity (in terms of living standards) which any given amount of money commands.
- These variations result from two types of causes[:]
(a) there are differences in present needs arising from certain objective circumstances, such as the number of people the taxpayer has to support, which may differentiate the `means` of men of normally equal `wealth`;
(b) there are differences in the relationship between a nominal amount of wealth and the spending opportunity it affords in a particular period. Obvious differences of this kind are between a man who draws a regular income from property and another man who earns an equal income, but being propertyless, must make provision out of it for the period of his retirement, against a failure of health etc.: or between a man who earns a regular salary and another who in a particular year earns an identical sum from a bestseller, but cannot expect a regular repetition of his performance or luck in subsequent years.