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.     

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.     

Nonseparable preferences and optimal social security systems

In this paper, we consider economies in which agents are privately informed about their skills, which evolve stochastically over time. We require agents' preferences to be weakly separable between the lifetime paths of consumption and labor. However, we allow for intertemporal nonseparabilities in preferences like habit formation. In this environment, we derive a generalized version of the Inverse Euler Equation and use it to show that intertemporal wedges characterizing optimal allocations of consumption can be strictly negative. We also show that preference nonseparabilities imply that optimal differentiable asset income taxes are necessarily retrospective in nature. We show that under weak conditions, it is possible to implement a socially optimal allocation using a social security system in which taxes on wealth are linear, and taxes/transfers are history-dependent only at retirement. The average asset income tax in this system is zero.     

Property taxes and dynamic efficiency: A correction

According to Kim and Lee (1997), property taxes as opposed to capital gain taxes and taxes on rent endanger dynamic efficiency. The present paper shows that the choice of the tax base is immaterial. What counts is whether the taxes eliminate the after-tax rent. Empirical evidence suggests that this is not the case.     

Love and taxes – and matching institutions

Abstract Income disparities and the intra‐family redistribution implied by a marriage may induce a high‐income earner to abstain from marrying a low‐income earner even though they would be a perfect match emotionally. Redistributive income taxation eases this problem, and the design of marriage matching institutions interacts with this role of redistributive taxation. Matching institutions that ensure that people largely from the same income groups meet each other can substitute for redistribution. Matching across income groups that focuses on emotional quality or preference congruence of the match may increase the efficiency‐enhancing role of taxation.     

Income taxes, spending composition and long-run growth

The focus of this paper is threefold. First, it reexamines the impact on long-run growth of changes in flat-rate income taxes when a fraction of total government expenditures is used to provide public services that affect the productivity of privately held inputs. Second, for a given tax policy, this paper studies the impact of government expenditure composition on the rate of economic growth. Third, since demographics follow an overlapping generations structure and fiscal policy affects the economy's productivity, the paper features the role of productivity as a means of redistributing income across generations. The economy is analyzed numerically and policy experiments are carried out.     

A contest with the taxman - the impact of tax rates on tax evasion and wastefully invested resources

We develop a moral hazard model with auditing where both the principal and the agent can influence the probability that the true state of nature is verified. This setting is widely applicable for situations where fraudulent reporting with costly state verification takes place. However, we use the framework to investigate tax evasion. We model tax evasion as a concealment-detection contest between the taxpayer and the authority. We show that higher tax rates cause more evasion and increase the resources wasted in the contest. Additionally, we find conditions under which a government should enforce incentive compatible auditing in order to reduce wasted resources.     

Optimal contracting with dynastic altruism: Family size and per capita consumption

We use a Barro–Becker model of endogenous fertility, in which parents are subject to idiosyncratic shocks that are private information (either to labor productivity or taste for leisure), to study the efficient degree of consumption inequality in the long run. The planner uses the trade-off between family size and future consumption and leisure, to provide incentives for workers to reveal their shocks. We show that in this environment, the optimal dynamic contract no longer features immiseration in consumption. We also discuss the implications of the model on the long run properties of family size in the optimal contract and show that the long run trend in dynasty size can be either positive or negative depending on parameters.     

The impact of prudence on optimal prevention revisited

We re-examine the link between absolute prudence and self-protection activities. We show that the level of effort chosen by an agent with decreasing absolute prudence is larger than the optimal effort chosen by a risk-neutral agent if the degree of absolute prudence is less than a threshold that is utility-independent and empirically verifiable.     

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.     

Implementing efficient allocations in a model of financial intermediation

In a finite-trader version of the Diamond and Dybvig (J. Polit. Econ. 91 (1983) 401) model, the ex ante efficient allocation is implementable by a direct mechanism (i.e., each trader announces the type of his own ex post preference) in which truthful revelation is the strictly dominant strategy for each trader. When the model is modified by formalizing the sequential-service constraint (cf. Wallace (Fed. Reserve Bank Minneapolis Quart. Rev. 12 (1988) 3)), the truth-telling equilibrium implements the symmetric, ex ante efficient allocation with respect to iterated elimination of strictly dominated strategies.     

A note on optimal procurement contracts with limited direct cost inflation

Laffont and Tirole's [Using cost observation to regulate firms, J. Polit. Econ. 94 (1986) 614-641] pioneering analysis identifies the optimal procurement contract when the supplier can readily inflate his innate production cost without detection. When the buyer has some ability to limit such cost inflation, an alternative contract can outperform the contract identified by Laffont and Tirole. The alternative contract induces substantial pooling, discontinuous production costs and effort supply, and rent that varies non-monotonically with innate cost.     

When is multidimensional screening a convex program?

A principal wishes to transact business with a multidimensional distribution of agents whose preferences are known only in the aggregate. Assuming a twist (= generalized Spence-Mirrlees single-crossing) hypothesis, quasi-linear utilities, and that agents can choose only pure strategies, we identify a structural condition on the value b(x,y) of product type y to agent type x — and on the principal?s costs c(y) — which is necessary and sufficient for reducing the profit maximization problem faced by the principal to a convex program. This is a key step toward making the principal?s problem theoretically and computationally tractable; in particular, it allows us to derive uniqueness and stability of the principal?s optimal strategy — and similarly of the strategy maximizing the expected welfare of the agents when the principal?s profitability is constrained. We call this condition non-negative cross-curvature: it is also (i) necessary and sufficient to guarantee convexity of the set of b-convex functions, (ii) invariant under reparametrization of agent and/or product types by diffeomorphisms, and (iii) a strengthening of Ma, Trudinger and Wang?s necessary and sufficient condition (A3w) for continuity of the correspondence between an exogenously prescribed distribution of agents and of products. We derive the persistence of economic effects such as the desirability for a monopoly to establish prices so high they effectively exclude a positive fraction of its potential customers, in nearly the full range of non-negatively cross-curved models.     

Direct versus intermediated finance: An old question and a new answer

We consider a closed economy where a risk neutral bank competes with a competitive bond market. Firms can finance a risky project either by a bank credit or by issuing a bond which is directly sold to risk averse investors who also hold safe deposits at the bank. We show that the bank tends to allocate more capital to lower quality projects but there are some interesting qualifications. If the asymmetric information concerns only the success probability, then we observe adverse selection while if it concerns only the expected return, bad types are driven out of the market.