On optimal redistributive capital taxation

This paper addresses conflicting results regarding the optimal taxation of capital income. Judd proves that in a steady state, there should be no taxation of capital income. Lansing studies a logarithmic example of one of Judd's models and finds that the optimal steady‐state tax on capital income is not always zero—it is positive in some specifications and negative in some others. There appears to be a contradiction. However, I show that Lansing derives his result by relaxing the convergence hypotheses of Judd's theorem. With less restrictive hypotheses, a wider range of primitives (parameter values, initial condition, etc.) satisfy the hypotheses and because each specification of primitives generates its own optimal time path(s) for the model's variables, it follows that a wider range of time paths with a wider range of steady‐state properties is possible. This raises a question. What happens if the convergence hypotheses are weakened further so that they are satisfied by a wider yet range of primitives? I find that at any interior steady state for the model's optimal tax equilibrium, either the capital tax is zero or else the elasticity of marginal utility is unitary which is satisfied identically in Lansing's log example. In effect, Lansing's example illustrates the only way in which an interior steady state can violate the zero tax result.     

On the optimality of optimal income taxation

The Mirrleesian model of income taxation restricts attention to simple allocation mechanism with no strategic interdependence, i.e., the optimal labor supply of any one individual does not depend on the labor supply of others. It has been argued by Piketty (2009) [12] that this restriction is substantial because more sophisticated mechanisms can reach first-best allocations that are out of reach with simple mechanisms. In this paper, we assess the validity of Piketty?s critique in an independent private values model. As a main result, we show that the optimal sophisticated mechanism is a simple mechanism, or, equivalently, a Mirrleesian income tax system.     

On the optimal income taxation and educational decisions

In this paper we consider three different ways of incorporating individuals' educational choices into the design of optimal income tax policy. In one variant of the model (case 2), where an individual chooses his education before knowing his ability and after that education makes his labour supply decisions on the basis of known ability, it is shown that qualitative features of the optimal income tax schedule are not similar to those of the standard optimal income tax model. The marginal tax rate is generally not zero at the endpoints of distribution but is most likely negative. Using numerical methods, some interesting features quite different from earlier numerical results are revealed, especially in the second case. For example, the marginal tax rate is non-decreasing in income for a substantial income range. In addition, our calculations support neither the traditional views on the egalitarian nature of equal education nor its disadvantageous consequences in the perfect utilitarian society.     

On the undesirability of commodity taxation even when income taxation is not optimal

An important result due to Atkinson and Stiglitz (1976) [Atkinson, A.B., Stiglitz, J.E., 1976. The design of tax structure: Direct versus indirect taxation. Journal of Public Economics 6, 55–75.] is that differential commodity taxation is not optimal in the presence of an optimal nonlinear income tax (given weak separability of utility between labor and all consumption goods). This article demonstrates that this conclusion holds regardless of whether the income tax is optimal. In particular, given any commodity tax and income tax system, differential commodity taxation can be eliminated in a manner that results in a Pareto improvement. Also, differential commodity taxation can be proportionally reduced so as to generate a Pareto improvement. In addition, for commodity tax reforms that neither eliminate nor proportionally reduce differential taxation, a simple efficiency condition is offered for determining whether a Pareto improvement is possible.     

Markov-perfect optimal taxation

In this paper we study optimal taxation in a dynamic game played by a sequence of governments and the private sector. We focus on the Markov-perfect equilibrium of this game under two different assumptions on the extent of government's intra-period commitment, which in turn define two within-period timings of actions. Our results show that the extent of government's intra-period commitment has important quantitative implications for policies, welfare, and macroeconomic variables, and consequently that it must be explicitly stated as one of the givens of the economy, alongside preferences, markets and technology. We see this as an important result, since most of the previous literature on Markovian optimal taxation has assumed, either interchangeably or unnoticeably, different degrees of government's intra-period commitment.     

On the optimal income taxation: Some further numerical results

Using numerical calculations we show in the optimal income tax model that a realistic value for the elasticity of substitution between consumption and leisure (?=0.5) leads to conclusions different from some of those drawn by Mirrlees (1971) and Atkinson (1973). The marginal tax rates are not so low and the shape of the tax schedule is for a great majority of the population substantially nonlinear. A new feature in our calculations is that both results come out without going to maximin, as done by Atkinson (1973). We study in special cases the locality of the zero limit of the marginal tax rate at the upper end of the ability distribution and we achieve a very definite conclusion: this result is really very local. We also present an interesting approximation result concerning the relationship between the level of the government revenue and the marginal tax rate for individuals with high ability. An important methodological remark analogous to Sen's critique on the ethical measures of inequality is made on the interpretation of optimal income tax calculations.     

Externalities and optimal taxation

This paper reexamines the optimal tax design problem (income and commodities) in the presence of externalities. The nature of the second–best, and the choice of the tax instruments, are motivated by the informational structure in the economy. The main results are: (i) environmental levies (linear or nonlinear) differ in formula from Pigouvian taxes by the expressions for the optimal tax on private goods; (ii) externalities do not affect commodity tax formulas (linear and nonlinear) for private goods; (iii) externalities do not affect the income tax structure if commodity taxes are nonlinear and affect it if commodity taxes are linear; and (iv) a general income tax plus strictly Pigouvian taxes are sufficient for efficient taxation if individuals of different types have identical marginal rates of substitution (at any given consumption bundle).     

On a simple rule for the optimal inflation rate in second best taxation

The optimal inflation rate is analyzed in the framework of dynamic second best with endogenous factor prices. It is shown that when the marginal excess burden of taxation is relatively small, the optimal inflation rate is approximated by a simple rule. The paper also analyzes the robustness of this rule to the specification of the model (money as an input in utility or production).     

Moral hazard and optimal commodity taxation

This paper demonstrates that in an economy with moral hazard and more than one commodity, competitive equilibrium is not constrained-efficient. To correct the market failure, differential commodity taxation is necessary. A general optimal tax formula is derived, and special cases of is discussed.     

Financing education using optimal redistributive taxation

In this article, the joint use of an income tax and public provision of education as instruments to achieve the government’s distributional objectives is considered. Individuals differ in innate labour productivity and in aptitude to acquire skills through education. Actual labour productivity depends on both innate skill and the amount of education received. Using a generalized version of the Mirrlees tax problem that incorporates these features, qualitative properties of an optimal tax schedule are investigated.     

Union strategy and optimal direct taxation

Restrictions on working hours are more important in countries with a large welfare state. We show that this empirical observation is consistent with the strategic effects of such restrictions in a welfare state in the context of optimal direct taxation in the tradition of Mirrlees (1971) [Mirrlees, J.A., 1971. An exploration in the theory of optimum income taxation. Review of Economic Studies 38, 175–208]. Our results also apply to non-welfarist states that have income redistribution, but not in purely extortionary states.     

Corporate taxation and the optimal investment decisions of firms

The effects of a corporate profits tax on the choice of technique depends on the criterion used to make this choice. Harberger concluded that it would alter the optimal techniques because he was implicitly assuming that firms try to maximise the internal rate of return on their investment. Stiglitz, using the maximisation of present value criterion, with a rate of interest lower than the rate of profits, concluded that the optimal techniques would not be affected by this tax. The appropriate criterion depends on the assumptions made about the scope for entrepreneurial activity and its relation to capital.     

Public health insurance and optimal income taxation

If individuals differ not only in their inherent capacity to earn income, but also in the probability that they will fall ill, can subsidized public health insurance be justified on the grounds that it serves as an efficient tool to redistribute welfare? This question is analyzed in a model where the social welfare function is a weighted average of individual expected utilities, and where taxation is by a linear income tax. The answer is ‘yes’, except in certain special cases.     

Measurable welfare change with optimal commodity taxation

This paper extends the recent work of Julian Le Grand on the measurability of welfare changes in the presence of second-best taxation to the case of optimal commodity taxes and shows that the effects of public sector activities in the presence of such taxes may be accurately measured by use of observable market data.     

Altruism,jealousy and the theory of optimal non-linear taxation

This paper studies optimal non-linear taxes in a world in which there is altruism and jealousy. A formula for optimal marginal tax rates is derived which turns out to be a simple and intuitively appealing extension of a result due to Mirrlees. The paper shows that in this sort of economy all of optimal tax theory's general results either no longer hold or need not hold, and it sets out appropriate modifications to standard tax rules.     

A contribution to the theory of optimal utilitarian income taxation

The paper provides a new formulation of the Mirrlees–Seade theorem on the positivity of the optimal marginal income tax, under weaker assumptions and in a more general model. The formulation of the theorem is independent of whether the model involves finitely many types or a continuous type distribution. The formal argument makes the underlying logic transparent, relating the mathematics to the economics and showing precisely how each assumption enters the analysis.     

Income taxation of U.S. households: Facts and parametric estimates

We use micro data from the U.S. Internal Revenue Service to document how Federal Income tax liabilities vary with income, marital status and the number of dependents. We report facts on the distributions of average taxes, properties of the joint distributions of taxes paid and income, and discuss how taxes are affected by marital status and the number of children. We also provide multiple parametric estimates of tax functions for use in applied work in macroeconomics and public finance.     

The geometry of optimal taxation: a primal approach

We characterize zero tax results geometrically as a condition on indifference curves and the implementability constraint. The condition can also be expressed as a generalized homotheticity condition on the utility function and also extends older results on uniform taxation that use the duality approach. Many zero taxation results in dynamic macroeconomics can be derived from our characterization; thus it provides a unified framework for a systematic study of these phenomena. Our geometric method also allows to study the sign of deviations from zero tax results in more complicated frameworks such as taxation without commitment.