Optimal linear income taxation with partial information

This letter presents a preliminary analysis of a tax problem whereby the tax function can depend not only on income but also on variables which are correlated with ‘earning ability’ and are known to the government. Our main result suggests that the tax system improved through increased use of such variables, and the optimal tax rate becomes larger.     

Optimal linear income taxation with general equilibrium effects on wages

The paper argues that the endogeneity of wages may make a considerable difference to optimal linear tax rates. In this case there is not only the usual direct redistribution via the fiscal system but also the general equilibrium redistribution due to the change in wages. Depending on the elasticity of substitution of the production function and the labour supply elasticities these may be reinforcing or opposing. It is shown that the general equilibrium effect may plausibly outweigh the direct effect so that net redistribution to the lower paid involves a wage subsidy financed by a lump-sum tax.     

Optimal income taxation with tax avoidance

We determine the optimal income tax schedule when individuals have the possibility of avoiding paying taxes. Considering a convex concealment cost function, we find that a subset of individuals, located in the interior of the income distribution, should be allowed to avoid taxes, provided that the marginal cost of avoiding the first euro is sufficiently small. This contrasts with the results of Grochulski who shows that, using a subadditive cost function, all individuals should report their true income. We also provide a characterization of the optimal income tax curve.     

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.     

Optimal income taxation in models with endogenous fertility

This paper studies the efficient taxation of factor income in infinite-lived models with elastic fertility choices. Two models are considered, one with physical capital only, and one with physical and human capital. In the model with physical capital only, capital income should be subsidized, while labor income taxed. In the model with two types of capital, instead, Ramsey optimality prescribes that the tax on physical capital is zero (negative), if effective labor is constant (decreasing) returns to scale in human capital and market goods, while the tax on human capital is negative and the tax on effective labor positive. Our findings depart from those obtained in immortal models with an endogenous labor supply and constant population growth, because physical and human capital affect the demand for fertility.     

Optimal non-linear income taxation for reduction of envy

This paper examines the optimal non-linear income taxation problem based on λ-equitability. An allocation is λ-equitable if no agent envies a proportion λ of the bundle of any other agent. We examine the properties of Pareto undominated allocations for various λ-equitability requirements. When there is one output, the marginal income tax rate can increase only if leisure is a luxury. In a multi-commodity model with commodity taxes, the goods preferred by the low skilled agent and/or those with high Hicksian elasticities are taxed more heavily. When preferences exhibit quasi-linearity, we can show that the introduction of the λ-equitability constraint increases the marginal income tax rates of the entire population.     

Optimal mixed taxation,public goods and the problem of high-skilled emigration

The optimal income tax model under the threat of migration of Simula and Trannoy (J Public Econ 94:163–173, 2010; Soc Choice Welf 39(4):751–782, 2012) is extended to include indirect taxes and public goods. This enables us to conclude that: (1) optimal income tax rates are higher than in the absence of indirect taxation, and may be positive at the top of the skills distribution; (2) indirect taxes, à la Corlett and Hague, may help mitigate the loss of redistributive capacity arising from income taxation caused by migration threats; (3) migration encourages the provision of the public goods preferred by the most productive workers; (4) optimal tax and public goods provision policies against the emigration of the highly-skilled are connected through the conditions for Pareto efficiency; (5) if the number of potential migrators is large, it may be desirable to violate classical tax rules to retain the most able in the home country; (6) when migration costs are exogenously given and utility is weakly separable, Simula and Trannoy’s results are restored; (7) if migration costs are endogenous, the Atkinson and Stiglitz theorem breaks down and the taxation of country-specific goods becomes desirable, even if utility is strongly separable.     

Optimal linear taxation of polluting oligopolists

A linear ad valorem tax can induce homogeneous oligopolists to produce at socially optimal levels, achieving the first-best allocation, in the presence of external costs that vary exogenously with aggregate output. The optimal tax rate is independent of private cost functions and thus reduces informational requirements on the regulator. Alternatively, if the regulator knows marginal private costs but not the pattern of firms' conduct or the slope of the demand curve, an iterative implementation of the tax is possible. Both blockaded and endogenous entry are considered, as is strategic behavior by firms toward the regulator.The views expressed in this paper are those of the author and do not necessarily reflect the views of the Federal Reserve Bank of Philadelphia or of the Federal Reserve System. The author is grateful to Paul Calem for helpful discussions and to two anonymous referees for helpful comments.     

Nonlinear taxation of income and education in the presence of income-misreporting

We study the joint design of nonlinear income and education taxes when the government pursues redistributive objectives. A key feature of our setup is that the ability type of an agent can affect both the costs and benefits of acquiring education. Market remuneration of agents depends on both their innate ability type and their educational choices. Our focus is on the properties of constrained efficient allocations when educational choices are publicly observable at the individual level, but earned income is subject to misreporting. We find that income-misreporting (IM) affects the optimal distortions on income and education and shed light on the reasons for it and mechanisms through which it is done. We show how and why IM strengthens the case for downward distorting the educational choices of low-ability agents. Finally, we find that IM provides another mechanism that makes commodity taxation useful.     

Optimal nonlinear income taxation with a finite population

In the standard optimal income taxation problem, tax payments depend only on each consumer's own actions. Piketty [J. Econ. Theory 61 (1993) 23-41] shows that, if one individual's tax schedule depends on others’ actions and the government knows the exact ability distribution, it can implement any undistorted allocation as the unique revelation game outcome. If some individuals misreveal their types, Piketty's mechanism may assign infeasible allocations. We require that tax schedules must balance the government budget for every possible vector of revelations. When individuals reveal their type by simple announcements, all undistorted allocations can be still implemented, even with off-equilibrium feasibility constraints.     

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 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.     

Optimal marginal and average income taxation under maximin

Using the Mirrlees optimal income tax model under maximin, we derive fairly mild conditions for a decreasing marginal tax rate throughout the skill distribution with no bunching, a strictly concave tax function in income and a single-peaked average tax schedule. Assuming additive preferences and an isoelastic disutility of labor function, these tax profiles are implied by aggregate skills that are non-decreasing with the skill level. If preferences are quasilinear in leisure or in consumption, these tax profiles are also obtained under a large set of skill distributions.     

Optimal nonlinear taxation of income and savings without commitment

When a government is unable to commit to its future tax policies, information about taxpayers' characteristics revealed by their behavior may be used to extract more taxes from them in the future. We examine the implications of this ratchet effect for the design of redistributive income and savings tax policies in a two‐period model with two types of individuals who only differ in their skill levels. When commitment is not possible, it may be optimal to separate, pool, or partially pool different types in period one. The nature of the distortions to labor supplies and savings are investigated for each of these three regimes. The identification of the optimal regime is investigated numerically.     

Optimal income taxation when couples have endogenous bargaining power

This study examines the optimal income taxation for a two-earner household, where the couple bargains over their private goods consumption and time allocation between work and leisure. In the model, bargaining power is determined endogenously by the income gap between the two earners. Conventional studies have shown that the higher income tax rate should be imposed on the individual with the smaller wage elasticity, typically the individual with the higher productivity. In contrast to conventional argument, this study shows that the optimal tax rate on the household member with the higher productivity is lower than that of the individual with the lower productivity if the required tax revenue is relatively small and the influence of the gender income gap on the power balance of the couple is moderate. This is because such a tax structure encourages the labor supply of the individual with the higher productivity to mitigate the decrease in the household’s consumption induced by income taxation.     

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.     

Optimal labor income taxation in a two-sector dynamic general equilibrium model

This paper presents a new approach to the two-sector optimal taxation problem. We derive the optimal labor income tax rate which depends on factor intensity across sectors. It is the labor intensity that determines the initial wage rate, and therefore the optimal labor tax rate. We show that an increase in the initial relative price of consumption goods decreases the optimal tax rate on labor income in the case that the consumption goods sector is capital-intensive while it increases the optimal tax rate on labor income in the case that the investment goods sector is capital-intensive.     

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.