Optimal Dynamic Nonlinear Income Taxation under Loose Commitment

This paper examines an infinite-horizon model of dynamic nonlinear income taxation in which there exists a small probability that the government cannot commit to its future tax policy. In this "loose commitment" environment, we find that even a little uncertainty over whether the government can commit yields substantial effects on the optimal dynamic nonlinear income tax system. Under an empirically plausible parameterization, numerical simulations show that high-skill individuals must be subsidized in the short run, despite the government's redistributive objective, unless the probability of commitment is higher than 98%. Loose commitment also reverses the short-run welfare effects of changes in most model parameters. In particular, all individuals are worse-off, rather than better-off, in the short run when the proportion of high-skill individuals in the economy increases. Finally, our main findings remain qualitatively robust to a setting in which loose commitment is modelled as a Markov switching process.Dynamic Income Taxation, Loose Commitment

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 taxation model leads to higher marginal income tax rates for both types of agents. Specifically, the high-skill type faces a positive marginal income 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 taxation 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 income tax rates. By contrast, if the government cannot pre-commit, the high-skill type will face a negative marginal income tax rate, whereas the effect of habit formation on the low-skill type's marginal tax rate is ambiguous.Income Taxation; Habit Formation; Commitment

Fiscal policy, increasing returns, and endogenous fluctuations

We examine the quantitative implications of government fiscal policy in a discrete-time one-sector growth model with a productive externality that generates social increasing returns to scale. Starting from a laissez-faire economy that exhibits an indeterminate steady state (a sink), we show that the introduction of a constant capital tax or subsidy can lead to various forms of endogenous fluctuations, including stable 2-, 4-, 8-, and 10- cycles, quasi-periodic orbits, and chaos. In contrast, a constant labor tax or subsidy has no effect on the qualitative nature of the model's dynamics. We also show that the use of local steady-state analysis to detect the presence of multiple equilibria in this class of models can be misleading. For a plausible range of capital tax rates, the log-linearized dynamical system exhibits saddle-point stability (suggesting a unique equilibrium) while the true nonlinear model exhibits global indeterminancy. Finally, we explore the use of a state-contingent capital subsidy/tax scheme for stabilization purposes. We show that a local control policy designed using the log-linearized model can rule out sunspot equilibria near the steady state but may not prevent fluctuations arising from global indeterminacy. We proceed to use the nonlinear model to design a policy that can stabilize the economy against all forms of endogenous fluctuations and select a globally unique equilibrium.Fiscal policy ; Business cycles ; Chaotic behavior in systems

Capital-Labor Substitution, Equilibrium Indeterminacy, and the Cyclical Behavior of Labor Income

This paper examines the quantitative relationship between the elasticity of capital-labor substitution and the conditions needed for equilibrium indeterminacy (and belief-driven áuctuations) in a one-sector growth model. Our analysis employs a ìnormalizedîversion of the CES production function so that all steady-state allocations and factor income shares are held constant as the elasticity of substitution is varied. We demonstrate numerically that higher elasticities cause the threshold degree of increasing returns for indeterminacy to decline monotonically, albeit very gradually. When the elasticity of substitution is unity (the Cobb-Douglas case), our model requires increasing returns to scale of around 1.08 for indeterminacy. When the elasticity of substitution is raised to 5, which far exceeds any empirical estimate, the threshold degree of increasing returns reduces to around 1.05. We also demonstrate analytically that laborís share of income becomes pro-cyclical as the elasticity of substitution increases above unity, whereas laborís share in postwar U.S. data is countercyclical. This observation, together with other empirical evidence, indicates that the elasticity of capital-labor substitution in the U.S. economy is actually below unity.Capital-Labor Substitution, Equilibrium Indeterminacy, Capital Utilization, Real Business Cycles, Labor Income

Indeterminacy and stabilization policy

A demonstration of how an income tax schedule that exhibits a progressivity feature can ensure saddle-path stability in a one-sector, real business-cycle model with sufficient increasing returns in production, thereby shielding the economy against sunspot fluctuations.Economic stabilization ; Business cycles

Indeterminacy with No-Income-Effect Preferences and Sector-Specific Externalities

We examine a two-sector real business cycle model with sector-specific externalities in the production of distinct consumption and investment goods. In addition, the household utility is postulated to exhibit no income effect on the demand for leisure. Unlike in the one-sector counterpart, we show that equilibrium indeterminacy can result with sufficiently high returns-to-scale in the production of investment goods. We also find that the smaller the labor supply elasticity, the lower the threshold level of returns-to-scale needed for generating indeterminacy and sunspots. This finding turns out to be exactly the opposite of that in all existing RBC-based indeterminacy studies.Indeterminacy, Income Effect, Sector-Specific Externalities

Tax structure and welfare in a model of optimal fiscal policy

A study of the welfare implications of some basic structural features of the U.S. tax code, including the tax deductibility of depreciation and the practice of taxing labor income differently than capital income. The results show that long-run welfare and output can be improved by a policy of accelerated depreciation, whereby the depreciation rate for tax purposes exceeds the rate of economic depreciation.Taxation ; Fiscal policy

Social Status and Optimal Income Taxation

This paper examines the optimal (first-best) fiscal policy in a stochastic, infinite-horizon representative agent model that exhibits consumption-enhanced as well as wealth-enhanced social status in the household utility. We show that the optimal labor tax rate is a positive constant that is used to correct negative consumption externalities. The optimal capital tax rate is also positive in order to overturn agents' status-seeking capital over-accumulation. Moreover, we find that in contrast to a conventional automatic stabilizer, the optimal capital tax moves in the opposite direction with shocks to firms' production technology. This result turns out to be qualitatively consistent with the discernible empirical evidence that many countries have implemented procyclical fiscal policies.Social Status, Optimal Income Taxation