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.     

Voting over selfishly optimal tax schedules: Can Pigouvian tax redistribute income?

This paper studies pairwise majority voting over selfishly optimal nonlinear income tax schedules proposed by a continuum of individuals who differ in privately observable skills and make consumption comparisons, which creates a negative positional externality. It shows that the tax schedule preferred by the median skill type will win the voting contest. Given a reference consumption defined as the average consumption in the population, all skills face the same Pigouvian tax rate in the utilitarian optimum, whereas in selfish optima high skills face a Pigouvian tax rate larger than that facing low skills, generating a novel income redistributive effect. Under a constant elasticity of labor supply, two more results are obtained. First, for Pareto, Champernowne, Weibull, and lognormal skill distributions, the selfishly optimal tax schedule facing high (low) skills tends to be more progressive when the bottom‐skill's (top‐skill's) status concern intensifies. Second, it identifies the conditions under which, in the voting equilibrium, high skills face higher marginal tax rates while low skills face lower ones than what they face in the utilitarian optimum.     

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.     

The failure of Ricardian equivalence under progressive wealth taxation

Although the Ricardian Equivalence Theorem holds under a linear estate tax schedule, it fails to hold under a nonlinear estate tax schedule. In a representative consumer economy, a temporary lump-sum tax increase reduces contemporaneous consumption. If different consumers face different marginal estate tax rates because they leave bequests of different sizes, a lump-sum tax increase redistributes resources from consumers in low marginal estate tax brackets to consumers in high marginal estate tax brackets; aggregate consumption may rise, fall, or remain unchanged. These departures from Ricardian Equivalence hold more generally under any nonlinear tax on saving, wealth or income accruing to wealth.     

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 Redistributive Income Taxation and Efficiency Wages*

In this paper, we integrate efficiency wage setting with the theory of optimal redistributive income taxation. In doing so, we use a model with two skill types, where efficiency wage setting characterizes the labor market faced by the low‐skilled, whereas the high‐skilled face a conventional, competitive labor market. We show that the marginal income tax implemented for the high‐skilled is negative under plausible assumptions. The marginal income tax facing the low‐skilled can be either positive or negative, in general. An increase in unemployment benefits contributes to a relaxation of the binding self‐selection constraint, which makes this instrument particularly useful from the perspective of redistribution.     

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.     

The effect of potential emigration on the optimal linear income tax

This paper amends a standard model of optimal linear income taxation to allow individuals to escape taxation by migrating. The income tax is used only to redistribute income in this model. It is found that, if individuals with low and high ability levels are prevented from migrating, then the optimal marginal tax and poll subsidy increase. But preventing migration at ability levels in some intermediate interval lowers the optimal marginal tax.     

Optimal Income Taxation with Risky Earnings: A Synthesis

We study optimal nonlinear income taxation when earnings can differ because of both ability and luck, so the income tax has both a redistributive role and an insurance role. A substantial literature on optimal redistribution in the absence of risk has evolved since Mirrlees's original contribution. The literature on the income tax as a social insurance device is more limited. It has largely assumed that households are ex ante identical so unequal earnings are due to risk alone. We provide a general treatment of the optimal income tax under risk when households differ in ability. We characterize optimal marginal tax rates and interpret them in terms of redistribution, insurance, and incentive effects. The case of ex ante identical households and the no‐risk case with heterogeneous abilities come out as special cases.     

Optimal income taxation with tax avoidance and endogenous labour supply

I determine the optimal income tax schedule when individuals both choose endogenously their labour supply and have the possibility of avoiding paying taxes. Considering a convex concealment cost function, I propose a formula for the optimal marginal tax rate, that generalizes the formula of the standard Mirrlees model to the case of tax avoidance. I also show that the results obtained by Casamatta (2021) in the fixed income case hold true when labour supply is endogenous: with a low enough marginal cost of avoidance, it is optimal to let some taxpayers, located in the interior of the skill distribution, avoid taxes.     

Optimum Taxation of Each Year's Income

In this paper, a two‐type, two‐period model of optimum income taxation is investigated. I assume full commitment and that current income determines the agents' tax burden in each period. It is shown that such a tax system does not allow one to implement the optimal long‐term tax contract and that it implies positive marginal tax rates at the upper end of the income distribution.     

RELATIVITY,INEQUALITY, AND OPTIMAL NONLINEAR INCOME TAXATION

How does concern for consumption relative to others (“relativity”) affect the structure of optimal nonlinear income taxation? Our article provides three sets of answers to this general question. First, it supports the conclusion in the literature that relativity leads to higher marginal tax rates. In doing so, it both generalizes some of the conditions under which this result is obtained in the literature and fleshes out the detailed structure for optimal marginal tax rates for specific functional forms for distribution, utility function, and social welfare function. Second, the article goes beyond the literature and examines the impact of relativity on the progression of optimal marginal tax rates. By and large, we find support for greater progressivity, defined as the steepness of the rise of the marginal tax rate schedule, as relativity concern increases. Third, none of the papers in the literature, to our knowledge, examines the interplay of relativity and inequality in determining the optimal structure of income taxes. Our special analytical cases and more general numerical calculations support the conclusion that higher inequality dampens the positive impact of greater relativity on the level and the progression of marginal tax rates. More work is needed to further explore this interaction between relativity and inequality that our analysis has uncovered.     

The impact of changing skill levels on optimal nonlinear income taxes

The impact of changing an individual's skill level on the solution to a finite population version of the Mirrlees optimal nonlinear income tax problem with quasilinear-in-leisure preferences is investigated. It is shown that it is possible to sign the directions of change in everyone's optimal consumptions and optimal marginal tax rates in response to such a change.     

FBT: How to Structure Remuneration Packages for 1986–87

The purpose of this article is to determine the optimal structure of remuneration packages in the new fringe benefits tax (FBT) environment. We will describe precisely how the optimal structure of remuneration packages depends upon the (marginal) rates of FBT, personal income tax and corporate tax. The fundamental decision rule for employers and employees to optimise the value of remuneration packages is quite simple. First substitute the FBT rate, f, and the employer's marginal tax rate, t, into I = f(1 + f - t)^-1. Then if the employee's marginal tax rate i is greater than I the employer should provide any benefits until i falls to the value I. At or below this point the employee would be better off to provide all subsequent benefits.     

Optimal tax treatment of the family: Married couples

This paper examines the appropriate tax treatment of the family in a series of analytical models and numerical examples. For a population of taxpaying couples which differ in earning capacity, we drive the optimal tax rates for each potential earner. These rates depend crucially upon own and cross labor supply elasticities and the joint distribution of wage rates. Our results suggest that the current system of income splitting in the United States, under which husbands and wives face equal marginal tax rates, is nonoptimal. Using results from recent econometric studies, and allowing for a sensitivity analysis, the optimal tax rates on secondary workers in the family are much lower than those on primary earners. Indeed, our best estimate is that the secondary earner would face tax rates only one-half as high as primary earners.     

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).     

Optimal income taxation with human capital accumulation and limited record keeping

This paper characterizes optimal income taxes in a dynamic economy where human capital is unobservable and the government is restricted to use taxes that depend only on current income. I show that unobservability of human capital tends to decrease the labor wedge, while the effect on the human capital wedge is uncertain. I also analyze the relationship between optimal taxes in economies with and without endogenous human capital and identify two qualitative reasons why the optimal tax codes will differ. I perform numerical simulations to calculate the quantitative relevance of endogenous human capital formation for optimal tax policy. I find that endogenous human capital lowers marginal tax rates by about 9% on average, as compared with a static model without human capital.     

Wage endogeneity,tax evasion,and optimal nonlinear income taxation

This paper studies the interaction between tax evasion and wage endogeneity within a Mirrleesian optimal tax framework. It characterizes the optimal marginal income tax rates on the skilled and the unskilled workers and the optimal amount of resources to be spent on deterring tax evasion. It shows that tax evasion weakens the incentives for the government to manipulate the marginal tax rates for the purpose of exploiting general equilibrium effects on wages. Moreover, the extent of this depends on the curvature of the evasion cost function. It also argues that marginal income tax rates are likely to be higher when the government attempts to deter evasion.     

Optimal top marginal tax rates under income splitting for couples

This paper provides formulas for optimal top marginal tax rates when couples are taxed according to income splitting between spouses, consumption is taxed, and the skill distribution is unbounded. Optimal top marginal income tax rates are computed for Germany using a dataset that includes the tax returns of all German top taxpayers. We find that the optimal top marginal tax rate converges to about 2/3 and convergence obtains at income levels that are substantially higher than those currently subject to the actual top tax rate.     

Optimal nonlinear income taxation with learning-by-doing

This paper examines a two-period model of optimal nonlinear income taxation with learning-by-doing, in which second-period wages are an increasing function of first-period labour supply. We consider the cases when the government can and cannot commit to its second-period tax policy. In both cases, the canonical Mirrlees/Stiglitz results regarding optimal marginal tax rates generally no longer apply. In particular, if the government cannot commit and each consumer's skill-type is revealed, it is optimal to distort the high-skill type's labour supply downwards through a positive marginal tax rate to relax an incentive-compatibility constraint. Our analysis therefore identifies a setting in which a positive marginal tax rate on the highest-skill individual can be justified, despite its depressing effect on both labour supply and wages.