1、所得税改革的发展和收入的影响英文文献及译文The Australian Economic Review, vol. 42, no. 4, pp. 496506For the StudentPersonal Income Taxation: From Theory to PolicyJ o h n C r e e d y Department of Economics, The University of Melbourne1.Introduction This article considers the relationship between economic theory and pers
2、onal income tax policy.It concentrates on the welfare analysis of personal income taxes and transferswhich together determine the relationship between gross and net incomesand the resulting advice which may be offered to policy-makers.The importance of this substantial component of the tax structure
3、 has been stressed by Ken Henry, who is the Chair of the Review Panel of the Australian Treasury, which is conducting an extensive review called Australias Future Tax System. He stated that, the tax-transfer system is a fundamental part of Australias social and economic infrastructure. It has been,
4、and will continue to be, shaped by the choices that Australians make about the type of society in which they choose to live. It can have a profound influence on the opportunities avail able to Australians.1 The personal tax-and-transfer system is also subject to an extensive revie win New Zea land b
5、y the Tax Working Group,under the aegis of the Victoria University of Wellington. An extensive review of the UK tax structure, called Reforming the Tax System for the 21st Century, has also recently been carried out under the aegis of the Institute for Fiscal Studies.It is inevitable that economic t
6、heory alone must be limited in terms of practical detail.Value judge ment are involved in decision making because virtually every tax-and transfer system has distributional implications.Many interdependencies are involved since taxes affect a wide range of economic behaviour and everyone is affected
7、 by them.However,economic analyses can provide valuable insights into the nature of those inter dependencies and can highlight potential unintended consequences or complications arising from tax changes.A further difficulty in linking theory and policy is that the possible effects of taxes are often
8、 expressed in terms of measures for which it is extremely difficult to obtain empirical counterparts.Insofar as tax models provide policy advice, it is often expressed in broad terms and is of a negative nature. However, in planning tax policy, it is extremely important to understand why clear resul
9、ts may not be achieved or why intuitively appealing results may not be reliable. As Edgeworth (1925, ii, p. 261) suggested when discussing income taxation and the concept of minimum sacrifice:Yet the premises, however inadequate to the deduction of a definite formula, may suffice for a certain negat
10、ive conclusion. The ground which will not serve as the foundation of the elaborate edifice designed may yet be solid enough to support a battering-ram capable of being directed against simpler edifices in the neighbour hood.Section 2 briefly discusses different approaches to the evaluation of taxes,
11、 placing the modern welfare analysis of taxation in historical perspective. Section 3 turns to the role of simple rules of thumb in policy advice,in particular the rule concerning a broad base and a low rate. Section 4 then considers the simplest possible tax-and-transfer system, the linear income t
12、ax, as a way of illustrating why optimal tax models quickly become intractable.Insights regarding the tax-rate schedule from optimal tax model ling are then discussed briefly in Section 5. Brief conclusions are drawn in Section 6.2.Modern Theory in PerspectiveIf asked for practical advice about taxa
13、tion,economists for many years would have referred to the famous four maxims of Adam Smith(1776): contribution according to ability to pay;4 certainty; convenience; and efficiency(including administrative costs, distortions to activity and the vexation and oppression involved).While the list of crit
14、eria was extended and clarified,5 in the discussion of ability to pay there was no acceptance of a redistributive role.6 The appropriate tax rate was thus determined by the independently given revenue requirement.7 An explicit preference for equality of treatment via proportional taxation was made m
15、ost clear in the following often-quoted remark made in 1845 by McCulloch, the author of the most extensive and systematic treatment of public finance in the classical literature:The moment you abandon the cardinal principle of exacting from all individuals the same proportion of their income or of t
16、heir property, you are at sea without rudder or compass, and there is no amount of injustice and folly you may not commit.McCulloch 1975, p. 147The main change in the approach to taxation came from the later integration of public finance into the general area of welfare economics, which was itself a
17、 major concomitant of the successful introduction of a utility-maxi mi sing approach to exchange in the1870s. However, the most systematic early developments came from Cohen-Stuart in 1889(Cohen-Stuart 1958) and Edgeworth (1897) in investigating the broad implications for progressivity of the minimi
18、 sati on of total disutility from taxationignoring any possible benefits.With the criterion of minimi sing total sacrifice,progression arises from decreasing marginal utility, but with equal absolute sacrifice, it depend son the precise behaviour of the marginal utility of income. Even here, there w
19、as no explicit independent role for redistribution: the maxi mand was strictly considered to be total utility.This movement reached its ultimate conclusion in the optimal tax literature, beginning virtually a century after the initial introduction of a utility analysis into economics. Thema thema ti
20、cal analyses of Edgeworth were extended by allowing, in particular, for la bo ur supply incentive effects of taxes and transfers,and including a range of specifications of the objectives of taxation, thus introducing an distributive role. In this final development,most of the important criteria sugg
21、ested by Smith and others were ignored. The relevant branch of welfare economics into which optimal tax theory falls is the theory of the second best, in view of the fact that the government is unable to tax individuals endowments of ability and instead taxes their incomes. Sometimes,stress is place
22、d on asymmetric information aspects,in that the government cannot observe ability levels.In drawing on this branch of modern economic theory to provide policy advice regarding tax structures, a number of serious difficulties immediately arise. Tax models have a way of getting very complicated very q
23、uickly.Many interdependencies are usually involved and clear views can only be obtained by abstracting from many realistic features. Indeed,many of the strong results from tax analyses(for example, certain equivalence results concerning uniform direct and indirect taxes in general equilibrium models
24、) are best interpreted as demonstrating that in fact they are most unlikely to apply in practice. The more realistic the model, the more it has to be restricted to highly specific questions.The theory of optimal income taxation provide san interesting case study. Analyses in this tradition have gene
25、rated valuable insights into the highly complex relationships involved.They have clarified what early investigators referred to as the grammar of arguments and there was no pret en c e that they were designed as guidance for practical policy advice. The results are largely of a negative nature. Neve
26、rtheless,it is possible that the substantial changes in the personal income tax structures of many countries over the last 30 years have been influenced by the optimal tax literature.These include, in particular, reductions in the number of marginal tax rates and the degree of rate progression. Care
27、 must be taken in making such statements. Establishing a clear rationale for each policy action is, of course, far from straightforward and the social welfare functions which play a fundamental role in optimal tax theory seldom represent the varied objectives of politicians.3. A Rule of ThumbThere a
28、re some basic principles which are worth keeping in mind in thinking about tax structures. These include points such that: there is a difference between legal and economic incidence; taxes can be shifted in various ways, including tax capi tali sati on; large efficiency costs can arise even when tax
29、es appear to have little effect on behaviour; and incentives matter.This list could easily be extended, but still does not provide strong positive advice. However,many economists take as a starting point the basic principle that the best taxes are those having a broad base and low tax rate. As a sim
30、ple rule of thumb, this is not a statement derived from a set of fundamental or universal principles, or axioms. It is meant only as a guiding aim.Departures from the rule require a special case to be made. A broad base, which is obtained by allowing few exemptions and deductions, is of course requi
31、red in order to achieve a low tax rate for a given revenue objective. In turn, the need for low rates is generally seen in terms of the efficiency costs of taxation, viewed in terms of the excess burden created by the tax distortion to behaviour: this measures the excess of the welfare cost arising
32、from the tax over the revenue raised. Appeal is made to the long-established result that the excess burden of a tax is approximately proportional to the square of the tax rate.13 Particular policies then require a trade-off to be made in terms of a balance of the perceived benefits of the proposed p
33、olicy against the estimated efficiency costs. It is necessary to make explicit the value judge ment s involved and the nature of the trade-off between gains and losses.Few countries score well when applying the basic broad baselow rate rule of thumb. For example, indirect tax structures often have a number of exemptions and more
