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.     

Depreciation and interest deductions and the effect of the corporation income tax on investment

In this paper, we examine the effect of the corporation income tax on the investment decision of the firm particularly with respect to the role of interest and depreciation deductions in determining the neutrality of the tax. We demonstrate the need for introducing a constraint on corporate borrowing before a meaningful analysis of the firm's behaviour under certainty is possible. The effect of a given tax and deduction scheme on the firm's investment decision is found to depend on the form of this constraint. We then relate our results to that of earlier authors and indicate some problems with their analyses.     

Depreciation and interest deductions and the effect of the corporation income tax on investment: A comment

When all jobs are full time and workers cannot substitute alternative jobs, the skills of workers are observable. Nevertheless, the optimum may involve a benefit for those who choose not to work (making their skills unobservable). When the tax structure and benefit for nonworkers are chosen to maximize welfare, they tradeoff the social marginal utility of consumption against the needed incentive to work. In contrast to more conventional models, the optimal tax schedule may have discontinuities and may involve subsidization of the work of low earners.     

Unemployment insurance and involuntary unemployment: The case of adverse selection

This paper studies the private and public provision of unemployment insurance in a model where equilibrium unemployment results from the use of the wage as a worker selection device. It is shown that private provision will not occur, essentially because those workers most desired by a firm place least value on such coverage. Respecting the same informational constraints, public provision necessarily gives rise to some distortions in participation decisions, but nonetheless is welfare improving in the aggregate.     

A general model of insurance under adverse selection

Summary. This paper considers optimal insurance schemes in a principal-agent multi-dimensional environment in which two types of risk averse agents differ in both risk and attitude to risk. Risk corresponds to any pair of distribution functions (not necessarily ordered by any of the usual dominance relations) and attitudes to risk are represented by any pair of non-decreasing and concave utility functions (not necessarily ordered by risk aversion). Results obtained in one-dimensional models that considered these effects separately and under more restricted conditions, are preserved in the more general set-up, but some of the questions we study can only be posed in the more general framework. The main results obtained for optimal insurance schemes are: (i) Insurance schemes preserve the order of certainty equivalents; consequently, the latter constitute a one-dimensional representation of types. (ii) Agents with the lower certainty equivalent are assigned full insurance. Partial insurance assigned to the others may entail randomization. (iii) Partially insured positions are an increasing function of the ratios of the probabilities that the two types assign to the uninsured positions. Most of these properties are preserved when, due to competition or other reasons, the insured certainty equivalents can not be set below pre-determined levels. Received: January 13, 1998; revised version: October 10, 1998     

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.     

An evolutionary analysis of insurance markets with adverse selection

The equilibrium nonexistence problem in Rothschild and Stiglitz's insurance market is reexamined in a dynamic setting. Insurance firms are boundedly rational and offer menus of insurance contracts which are periodically revised: profitable competitors' contracts are imitated and loss-making contracts are withdrawn. Occasionally, a firm experiments by withdrawing or innovating a random set of contracts. We show that Rothschild and Stiglitz's candidate competitive equilibrium contracts constitute the unique long-run market outcome if innovation experiments are restricted to contracts which are sufficiently “similar” to those currently on the market.     

Individual welfare,majority voting,and the properties of a linear income tax

A fundamental problem in public finance is the determination of parameters of income tax functions. This paper focuses on this problem in the context of a linear tax function whose parameters are chosen according to majority vote by the taxpayers. The possibility of conflict between high national income and distributional equity is explored and it is found that, even when the distribution of earning power is rightward skew, majority voting does not necessarily lead to the adoption of a tax function which has the average tax rate rising with income.     

The effect of marginal tax rates on taxable income: a panel study of the 1988 tax flattening in Canada

Federal tax reform in 1988 flattened the Canadian personal income tax schedule, changing the marginal tax rates for many individuals. Using methods similar to those applied by Auten and Carroll [Rev. Econ. 81(4) (1999) 681] in the study of the effects of the 1986 U.S. Tax Reform Act, we estimate the responsiveness of income to changes in taxes to be substantially smaller in Canada. However we find evidence of a much higher response in self-employment income, in the labor income of seniors and from those with high incomes.     

Genetic adverse selection: Evidence from long-term care insurance and Huntington disease

Individual, personalized genetic information is increasingly available, leading to the possibility of greater adverse selection over time, particularly in individual-payer insurance markets. We use data on individuals at risk for Huntington disease (HD), a degenerative neurological disorder with significant effects on morbidity, to estimate adverse selection in long-term care insurance. We find strong evidence of adverse selection: individuals who carry the HD genetic mutation are up to 5 times as likely as the general population to own long-term care insurance. This finding is supported both by comparing individuals at risk for HD to those in the general population and by comparing across tested individuals in the HD-risk population with and without the HD mutation.     

The optimal linear income tax: A diagrammatic analysis

This paper clarifies the role of the tax possibility frontier and the social indifference curve in the comparative statics analysis of the optimal linear income tax. By a mostly diagrammatic derivation of the results we confirm the conventional conjecture that the optimal marginal tax rate increases with the government's inequality aversion. On the other hand, we cannot always confirm analytically the conventional conjecture that the optimal marginal tax rate increases with the government's budgetary needs.     

Commons as insurance and the welfare impact of privatization

It is shown here that, despite the efficiency gains from privatization, when markets are incomplete, all individuals may be made worse off by privatization, even when the resource is equitably privatized. Such market incompleteness is common in the developing world and can explain the often encountered resistance to efficiency enhancing privatizing reforms, especially in the case of village level landholdings and forests. The advantage of common held property arises because of its superior insurance properties (which tend to provide income maintenance in low states). Sufficient conditions are established under which any feasible insurance scheme under private property cannot ex ante Pareto dominate allocations under the commons.     

企业所得税并轨对我国引进外国直接投资的影响

我国将要进行的内外资企业所得税并轨会使外资企业所得税负有所提高,来自中国香港和台湾地区的直接以及来自维尔京群岛、开曼群岛和新加坡等国际避税地的外国直接投资,很可能会因此转移到其他国家;而来自美国、欧盟及日本等发达国家的外国直接投资受到的影响则较小。但由于目前我国来自中国香港、台湾地区以及一些国际避税地的直接投资占有绝对的优势,已将近总额的60%,因此提高外资企业所得税率很可能会导致大量外资流向周边低税国家,从而对我国引进外国直接投资的总量产生较大影响。     

Taxation and income distribution: The Colombian tax reform of 1974

In late 1974 the Government of Colombia implemented a major tax reform package embracing virtually all aspects of the revenue system. The reform was designed to serve allocative and stabilization as well as redistributive goals. This paper focuses upon the likely impact of the 1974 tax measures upon income distribution. Section 2 describes the prevailing distribution of income prior to the reform. Section 3 presents a short outline of the principal features of the 1974 package, and sections 4 through 6 provide an evaluation of its redistributive effects. The authors conclude that the initial impact of the reform was undoubtedly progressive, as it likely served to shift as much as 1.5 percent of GDP away from the top quintile of the income distribution.     

Minimum standards, insurance regulation and adverse selection: evidence from the Medigap market

This paper examines the implications of minimum standards for insurance markets. I study the imposition of binding minimum standards on the market for voluntary private health insurance for the elderly. The central estimates suggest that the introduction of the standards was associated with an 8 percentage point (25%) decrease in the proportion of the population with coverage in the affected market, with no evidence of substitution toward other, unregulated sources of insurance coverage. To explore possible factors contributing to the impact of the minimum standards, I develop comparative static predictions of the impact of imposing minimum standards in an insurance market with adverse selection. The observed changes in market equilibrium associated with the minimum standards are broadly consistent with these predictions, providing evidence of the existence of adverse selection in this insurance market. More importantly, they suggest that the presence of adverse selection—which in principle may provide an economic rationale for minimum standards—in practice may have exacerbated the declines in insurance coverage associated with the minimum standards.     

The effects of tax reform on labor supply, tax revenue and welfare when tax avoidance matters

We examine how tax avoidance in the form of trade in well-functioning asset markets affects the study of labor supply. We discuss the implications for tax policy analysis, and we show that a failure to account for avoidance responses may lead to huge errors when analyzing how tax reform affects labor supply, tax revenue and the welfare cost of taxation. Our model may explain a number of otherwise hard to understand dimensions of taxpayer response.     

The distribution of abilities and the progressive income tax

This paper develops a model of endogenous labor supply, where agents are uncertain about their future wages. Assuming risk aversion, some redistributive taxation is thus warranted. It is shown that, for a particular parameterization of the tax system, an optimally progressive income tax exists. Comparative ststics analysis demonstrates how this tax system is effected by changes in the wage distribution. The paper ends with a discussion of whether an optimally progressive income tax can be politically sustained. It is shown that generally this is not the case in a political system with majority voting.