Optimal Nonlinear Income Taxation with Habit Formation

It has recently been shown that incorporating “keeping up with the Joneses” preferences into a prototypical two‐ability‐type optimal nonlinear income tax model leads to higher marginal tax rates for both types of agents. In particular, the high‐skill type faces a positive marginal tax rate, rather than zero as in the conventional case. In this paper, agents’ utility functions are postulated to exhibit “habit formation in consumption” such that the prototypical two‐ability‐type optimal nonlinear income tax model becomes a dynamic analytical framework. We show that if the government can commit to its future fiscal policy, the presence of consumption habits does not affect the standard results on optimal marginal tax rates. By contrast, if the government cannot precommit, the high‐skill type will face a negative marginal tax rate, while the low‐skill type’s marginal tax rate remains positive.     

Nonlinear Pricing, Redistribution, and Optimal Tax Policy

This paper examines the role of nonlinear pricing by public (or regulated) utilities as a redistributive mechanism in presence of an optimal nonlinear income tax. It models an economy with many types of persons who differ in two unobservable characteristics (earning abilities and tastes). We show that nonlinear pricing does have a redistributive role; it is not a substitute for an ill-designed tax policy. We prove, assuming separable preferences, that a person whose valuation of the public sector output is smaller than the average valuation of the population (all measured at the same consumption bundle) must face a marginal price for the good above its marginal cost. Further assuming that tastes and earning abilities are perfectly correlated, we prove that everyone must face a marginal price for the public sector's output which strictly exceeds its marginal cost if correlation is positive. These properties provide an economic rationale for the provision of "support for low-income consumers" as mandated by the universal service and similar regulatory policies. Finally, we show that with correlated characteristics, implementation can be achieved through two separate functions: a pricing function that depends only on the public sector output and a tax function that depends only on income.     

Optimal taxes on wealth and consumption in the presence of tax evasion

This article incorporates tax evasion into an optimum taxation framework with individuals differing in earning abilities and initial wealth. We find that despite the possibility of its evasion a tax on initial wealth should supplement the optimal nonlinear income tax, given a positive correlation between initial wealth and earning abilities. Further, even if income and initial wealth are taxed optimally, it is still desirable to levy a tax on commodities, though it can be evaded as well. Thus, our result provides a rationale for a comprehensive tax system. Optimal tax rates on commodities differ in general, however for the special case of a uniform evasion technology equal rates are optimal if preferences are homothetic and weakly separable.     

Optimal nonlinear income taxation with productive government expenditure

This paper develops an endogenous growth model with a production externality and nonlinear income taxation, and uses it to examine how the fiscal authority devises its nonlinear tax structure from the viewpoint of welfare maximization. It is found that, in the Barro (1990) model, Pareto optimality can be achieved if both policy instruments for the tax scalar and the extent of the tax progressivity/regressivity are set optimally.     

Optimal nonlinear income taxation with productive government expenditure

This paper develops an endogenous growth model with a production externality and nonlinear income taxation, and uses it to examine how the fiscal authority devises its nonlinear tax structure from the viewpoint of welfare maximization. It is found that, in the Barro (1990) model, Pareto optimality can be achieved if both policy instruments for the tax scalar and the extent of the tax progressivity/regressivity are set optimally.     

Income Taxation Rules and Stability of a Small Open Economy

This paper examines the stability of a small open economy under alternative income taxation rules. Using a one-sector real business cycle model with external increasing returns, we show that if the income tax schedule is linear, the small open economy will not generate equilibrium indeterminacy, but it exhibits a diverging behavior under certain conditions. In this case, an appropriate choice of nonlinear tax on the factor income may recover the saddle-point stability. We also reveal that if the taxation on the interest income on financial assets is regressive, then the small open economy may exhibit equilibrium indeterminacy. In this situation, a progressive tax rule on the interest income can contribute to eliminating sunspot-driven fluctuations.     

Production Efficiency and the Direct-Indirect Tax Mix

In the design of the optimal direct/indirect tax mix, the canonical view was laid by Atkinson and Stiglitz (1976) who showed that commodity taxes are unnecessary in an economy in which there is an optimal nonlinear income tax provided that commodities are separable from labor in the utility functions of all taxpayers, that the aggregators over these commodities are ordinally equivalent and that wages are fixed. When wages are endogenous, Naito (1999) showed that this result may not hold and in addition that production efficiency may not be Pareto optimal. Given an optimal nonlinear income tax, we show that production inefficiency is Pareto optimal if the aggregate technology set is strictly concave. The Atkinson–Stiglitz condition is neither necessary nor sufficient for zero commodity taxation and commodity taxes are part of almost all Pareto optima.     

Income tax deductions for losses as insurance revisited

Kaplow (1992) shows that allowing income tax deductions for losses as partial insurance is undesirable in the presence of private insurance markets. This paper revisits the issue by considering a model that integrates Kaplow (1992) with Stiglitz (1982). We address the following question: Whether the income tax deduction for losses is part of an optimal income tax system. We show that introducing the income tax deduction for uninsured losses to complement an optimal nonlinear labor income tax will Pareto-improve welfare, provided that: (i) information is incomplete for the government as in the Stiglitz framework, and (ii) the premium for private insurance is unfair or moral hazard is present.     

Fiscal and Monetary Policies in a Transactions‐Based Endogenous Growth Model with Imperfect Competition

This paper's model is capable of explaining the empirical evidence on the mixed growth‐rate effects of fiscal and monetary policies and a nonlinear inflation–growth relation. When monopoly power in the product market is strong/weak, an increase in the money growth rate or the income tax rate promotes/reduces the output growth rate through lowering/raising the equilibrium gross markup and increasing/reducing the net rate of return on capital. The fact that money can generate a positive growth rate effect allows for the appearance of a nonlinear inflation–growth relation. Such a nonlinear relation cannot be caused by changes in the income tax rate.     

Optimal Taxation with a Trade-off Between Income and Children

This paper explores the implications of endogenous fertility for optimal redistributive taxation in the presence of a trade-off between labour income and children. The labour supply is a decreasing function of the desired quantity and quality of children. Since children enter into the parent's budget constraint in a nonlinear form, their shadow prices are directly distorted by the income tax rate. It is shown that the substitution effects of the income tax rate on the quantity and quality of children cannot be signed uniquely although the effect on labour supply is negative. The aggregate substitution effect of the income tax rate on the quantity of children plays an important role in the determination of the signs of the income tax and child subsidy rates at a Rawlsian or Benthamite social welfare optimum.
JEL Classification Numbers: H21, J13, J22     

Is the Optimal Labor Income Tax Progressive in a Unionized Economy?*

This paper concerns optimal nonlinear labor income taxation in an economy with union wage setting and endogenous hours of work. The purpose is to study the determinants of tax progression. We show that the optimal degree of progression of the labor income tax depends on the extent to which the government can influence the wage rate via tax policy as well as on its ability to redistribute income across individuals. In addition, the argument for progressive labor income taxation depends on whether hours of work are chosen by the employed themselves or the union.     

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).     

Social norms and economic growth in a model with labor and capital income tax evasion

Empirical evidence suggests that low-income countries are characterized by high levels of labor and capital income tax evasion while the opposite is true for high-income countries. This paper proposes a model to study the relationship between economic growth and both types of income tax evasion. We show that the existence of a social norm towards tax compliance generates a complementarity between capital and labor income tax evasion which explains the decline of both the share of evaders in the population and the amount of tax evasion when countries accumulate capital. The model predicts that the level of tax morale is positively correlated with both types of income tax evasion and the level of income per capita, consistent with recent empirical evidence. Finally, a higher tax rate increases the share of evaders in the population and aggregate tax evasion.     

Optimal Nonlinear Redistributive Taxation and Public Good Provision in an Economy with Veblen Effects

This paper deals with the consequences of the assumption of negatively interdependent preferences for the shape of the optimal nonlinear income tax and the efficient level of public good provision in a setting where the agents' market ability is private information. The analysis points out that the terms added in the tax formulas due to the presence of Veblen effects might justify a reduction in the optimal marginal tax rates faced by the different individuals. Also, the desirability of negative marginal tax rates cannot be ruled out. With respect to the issue of the optimal level of public good provision, I derive a modified Samuelson rule and highlight the fact that the Veblen‐based part of the formula might require to distort downwards the efficient level of public good provision.     

Redistributive taxation as social insurance

The modern literature on nonlinear optimal taxation treats differences in income as being due to unobserved differences in ability. A striking result of this assumption is that high income agents should face a zero marginal tax rate. In this paper I assume that differences in observed income are due to exogenous differences in luck. Hence the optimal redistributive tax involves trading off the benefits due to ‘social insurance’ with the costs due to reduced incentives. I derive the optimal forms for linear and nonlinear taxes, and compute some algebraic and numeric examples. Typically high income individuals will face quite high marginal tax rates.     

Towards a Negative Income Tax System for Australia

The undue complexity of the Australian tax-transfer system is outlined as are the associated high effective marginal tax rates for many individuals and families. A negative income tax system is a possible solution to these problems.
The most radical version of negative income tax is a 'basic income/flat tax' system which combines universal tax credits (that vary according to presence of children, disability etc.) and a flat tax rate on private income. Using NATSEM's microsimulation model STINMOD it is found that to ensure that no current social security beneficiaries become worse off under such a system would either be very expensive to introduce or require a tax rate that is likely to be unacceptably high. Less radical versions of negative income tax are also costed, incorporating the possibility of varying tax rates, the tapering out of tax credits, and placing some restrictions on the granting of tax credits. This makes negative income tax look more feasible.
The analysis does not incorporate behavioural responses. Since the motivation for a negative income tax system is largely to achieve such responses (for example, labour supply responses), this feasibility analysis might have been unduly harsh. Research is required to incorporate behavioural responses into the analysis.     

PUBLIC GOOD PROVISION AND THE COMPARATIVE STATICS OF OPTIMAL NONLINEAR INCOME TAXATION*

Comparative static properties of the solution to an optimal nonlinear income tax problem are provided for a model in which the government both designs an income tax schedule for redistributive purposes and provides a public good optimally. There are two types of individuals, distinguished by their skill levels, who have the same quasilinear preferences for labor supply and the consumption of a private and a public good. Comparative statics are obtained for the weights in a weighted utilitarian social welfare function, the prices of the two goods, a taste parameter that measures the onerousness of working, and the skill levels.     

Optimal income taxation with a stationarity constraint in a dynamic stochastic economy

We consider the optimal nonlinear income taxation problem in a dynamic, stochastic environment when the government cannot change the tax rule as uncertainty resolves. Due to such a stationarity constraint, our taxation problem is reduced to a static one over an expanded type space that incorporates type evolution. We strengthen the argument in the static model that the zero top marginal tax rate result is of little practical importance because it only applies to the top of the expanded type space. If the maximal type increases over time, the person with top ability in any period but the last has a positive marginal tax rate.     

Optimal taxation with consumption time as a leisure or labor substitute

This paper studies the optimal commodity taxation problem when time taken in consumption is a perfect substitute for either labor or leisure. It shows that while labor substitutability affects the optimal tax structure, leisure substitutability leaves the classical optimal tax results intact. In the Ramsey tax framework with linear income taxes, whether the consumers have the same or different earning abilities, labor substitutes tend to be taxed at a higher rate than leisure substitutes with the tax differential being increasing in consumption time. This is not necessarily the case when one allows for nonlinear income taxation.