Social Insurance and Redistribution with Moral Hazard and Adverse Selection*

Rochet (1991) showed that with distortionary income taxes, social insurance is a desirable redistributive device when risk and ability are negatively correlated. This finding is re‐examined when ex post moral hazard and adverse selection are included, and under different informational assumptions. Individuals can take actions influencing the size of the loss in the event of accident (or ill health). Social insurance can be supplemented by private insurance, but private insurance markets are affected by both adverse selection and moral hazard. We study how equity and efficiency considerations should be traded off in choosing the optimal coverage of social insurance when those features are introduced. The case for social insurance is strongest when the government is well informed about household productivity.     

Markets as beneficial constraints on the government

We study the role of anonymous markets in which trades cannot be monitored by the government. We adopt a Mirrlees approach to analyze economies in which agents have private information and a benevolent government controls optimal redistributive tax policy. While unrestricted access to anonymous markets reduces the set of policy instruments available to the government, it also limits the scope of inefficient redistributive policies when the government lacks commitment. Indeed, the restrictions that anonymous markets impose on the optimal fiscal policy, especially on capital taxation and the history-dependence of income taxation, can have positive welfare effects in this case.     

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.     

The politics of redistributive social insurance

This paper analyses the political support for a social insurance that includes elements of redistribution when there exists an imperfect private insurance alternative. Individuals differ both in their income and risk. The social insurance is compulsory and charges an income-related contribution with pooling of risks. The private insurance is voluntary and charges a contribution based on individual risks. However due to the adverse selection problem, private insurance companies provide only partial insurance. Adopting a non-expected utility model, we show that there is a general majority support for social insurance and that this support is increasing with risk aversion. We also show that a mixed insurance is politically impossible, regardless of the degree of redistribution of social insurance and the joint distribution of risk and income in the population. Lastly, we analyse how the political support for social insurance is affected by any change in its redistributive component and the possibility of using genetic tests.     

Choice, price competition and complexity in markets for health insurance

The United States and other nations rely on consumer choice and price competition between competing health plans to allocate resources in the health sector. While a great deal of research has examined the efficiency consequences of adverse selection in health insurance markets, less attention has been devoted to other aspects of consumer choice. The nation of Switzerland offers a unique opportunity to study price competition in health insurance markets. Switzerland regulates health insurance markets with the aim of minimizing adverse selection and encouraging strong price competition. We examine consumer responses to price differences in local markets and the degree of price variation in local markets. Using both survey data and observations on local markets we obtain evidence suggesting that as the number of choices offered to individuals grows, their willingness to switch plans given a set of price dispersion differences declines, which allows large price differences for relatively homogeneous products to persist. We consider explanations for this phenomenon from economics and psychology.     

Redistributive taxation as social insurance

The modern literature on nonlinear optimal taxation treats differences in income as being due to unobserved differences in ability. A striking result of this assumption is that high income agents should face a zero marginal tax rate. In this paper I assume that differences in observed income are due to exogenous differences in luck. Hence the optimal redistributive tax involves trading off the benefits due to ‘social insurance’ with the costs due to reduced incentives. I derive the optimal forms for linear and nonlinear taxes, and compute some algebraic and numeric examples. Typically high income individuals will face quite high marginal tax rates.     

Unemployment insurance and redistributive taxation

This paper studies the simultaneous determination of the socially optimal levels of unemployment insurance, income taxation and experience rating. It argues that there is a normative justification for state unemployment insurance. When the government wishes to use redistributive taxes, but cannot enforce lump-sum transfers, it is not socially optimal for there to be full experience rating of unemployment insurance schemes: one distortion should be used to off-set another. The state must then intervene in the provision of insurance for those without jobs.     

Optimal Taxation of Bequests in a Model with Initial Wealth*

We formulate an optimal‐taxation model where parents leave bequests to their descendants for altruistic reasons. In contrast to the standard model, individuals differ not only in earning abilities, but also in initial (inherited) wealth. In this model, a redistributive motive for an inheritance tax – which is equivalent to a uniform tax on all expenditures – arises, given that initial wealth increases with earning abilities. The introduction of the inheritance tax either increases intertemporal social welfare or has an ambiguous effect, depending on whether the external effect related to altruism is accounted for in the social objective.     

Optimal unemployment insurance and redistribution

We characterize optimal income taxation and unemployment insurance in a search‐matching framework where both voluntary and involuntary unemployment are endogenous and Nash bargaining determines wages. Individuals decide whether to participate as job seekers and if so, how much search effort to exert. Unemployment insurance trades off insurance versus search and participation incentives. We also allow for different productivity types so there is a redistributive role for the income tax and show that a piecewise linear wage tax internalizes the macro effects arising from endogenous wages. Type‐specific lump‐sum taxes and transfers can then redistribute between individuals of differing skills and employment states. Our analysis embeds optimal unemployment insurance into an extensive‐margin optimal redistribution framework where transfers to the involuntarily and voluntarily unemployed can differ, and nests several standard models in the literature.     

Subjective well‐being,consumption comparisons,and optimal income taxation

We introduce reference consumption into the standard utility function from optimal tax analysis. Individuals compare their consumption “narrowly” with those of the same productivity, or “broadly” with the average consumption across society. In both narrow and broad equilibria reference consumption is an increasing function of the tax parameters, so generating new theoretical results. Individual well‐being decreases with the net wage (net‐of‐tax) rate for low productivity workers under narrow (broad) comparisons, thus adjusting redistributive taxation considerations. Further, in both cases reference consumption distorts labor supply away from the social optimum level, giving a distortion‐correcting role for taxation.     

Uncertainty, Commitment, and Optimal Taxation

This paper examines the optimal tax design problem in the presence of wage uncertainty. The wage has a continuous distribution, individuals are ex ante identical, preferences are separable in labor supply and goods, public policy aims at providing the population with social insurance, and the only restriction on the tax instruments is that emanating from lack of public observability of realized wages and labor supplies. We show that optimal tax structures depend crucially on whether it is labor supply or goods that consumers have to commit to before the resolution of uncertainty. Specifically, we prove that, in the absence of commitment, the social insurance problem collapses to the traditional optimal tax problem. Second, if labor supply is precommitted, it would be possible to effect a first-best outcome. Third, commitment to goods would make indirect taxation a useful instrument of tax policy even in the presence of a general income tax; it requires differential tax treatment of committed and noncommitted goods. Finally, if preferences are separable between the two types of goods, precommitted goods must be taxed at a uniform rate lower than that on the noncommitted goods.     

Redistributive taxation in a simple perfect foresight model

We investigate the redistributive potential of capital taxation in an intertemporal maximizing model of capital formation. First, even unanticipated redistributive capital taxation is severely limited in its effectiveness since it depresses wages. Second, under any convergent redistributive tax policy which maximizes a Paretian social objective, the capital income tax will converge to zero, independent of the factor supply elasticities. These results are independent of workers' holdings of capital.     

Redistribution and entrepreneurship with Schumpeterian growth

We examine the effects of redistributive taxation on growth and inequality in a Schumpeterian model with risk-averse agents. There are skilled and unskilled workers, and the growth rate is determined by the occupational choice of skilled agents between entrepreneurship and employment. We show that redistribution provides insurance to entrepreneurs and increases the growth rate. The effects on inequality are such that low tax rates increase inequality relative to laissez-faire due to changes in wages, but higher tax rates can simultaneously raise growth and reduce inequality. We contrast the optimal linear income tax with alternative policies for promoting R&D and find that it is preferable on both equity and efficiency grounds.      

Aspects of optimal unemployment insurance : Search, leisure, savings and capital market imperfections

Unemployment insurance is analysed in the optimal taxation framework. Benefits discourage search and thus raise unemployment. A perfect capital market model is developed and solved explicitly for a constant absolute risk aversion utility function. For ‘realistic’ parameter values low replacement rates (less than 50%) are optimal. If there is no lending or borrowing the optimal rates rise to about 75%. Alternative models also admit leisure as a good and the input to search; this reduces optimal replacement when the capital market is perfect. When it is nonexistent the optimal benefits depend on the value of leisure - rising as it falls. Alternatives to constant benefits conditional on continued unemployment are considered.     

Optimal Redistribution with Endogenous Social Norms

In this paper, we examine the effect of social norms on redistributive policies, where social norms are reflected in the degree of work participation among the different skill classes. Participation is driven both by the material incentives and heterogeneous preferences for leisure of each skill class, and by an endogenous social norm. Results for optimal redistributive taxation show that when the social norm enters as a benefit or cost for participants, participation taxes are generally lower than in its absence. Multiple participation equilibria can occur, and an engineered shift from a low‐ to a high‐participation equilibrium can be Pareto‐improving in the long run.     

Education,redistributive taxation and confidence

We consider redistributional taxation between people with and without human capital if education is endogenous and if individuals differ in their perceptions about own ability. Those who see their ability as low like redistributive taxation because of the transfers it generates. Those who see their ability as high may also like redistributive taxation because it stops other people receiving education and increases the quasi rents on their own human capital. It is surprising that this rather indirect effect can overcompensate them for the income loss from taxation and make the highly confident want higher taxes than the less confident do. The results, however, turn out to be in line with empirical evidence on the desired amount of redistribution among young individuals.     

Community rating and the market for private non-group health insurance

Prior research on adverse selection in health insurance markets has found only mixed evidence for adverse selection in group settings. We examine the impact of state community rating regulations enacted in the 1990s, which greatly limited insurers' ability to risk rate premiums, to determine if adverse selection is more evident in non-group insurance markets. Using data from large, national surveys we find evidence of a shift to a less healthy pool of non-group enrollees as a consequence of community rating. Community rating made healthy people 20 to 60% less likely to be insured by non-group health insurance; in addition, we found evidence that young and healthy people were 20 to 30% more likely to be uninsured as a result of community rating. We also find evidence that individuals in poor health were 35 to 50% more likely to be insured in the non-group market, but only limited evidence suggesting that persons in poor health were less likely to be uninsured. Our results are further supported by findings suggesting that non-group enrollees were sicker as a result of the community rating laws. Lastly, we find evidence suggesting that HMO penetration in the non-group market increased disproportionately in states that implemented community rating relative to states that did not.     

Income Taxation, Endogenous Factor Prices and Production Efficiency

In an analysis of a two‐type income tax model with endogenous wages, this paper shows that production efficiency is violated in the optimum with (i) non‐linear and (ii) linear income taxation if and only if a distortionary tax schedule is implemented. These findings complement earlier results of the literature. In passing, it is also shown that optima with non‐linear redistributive income taxation cannot be identified with the redistributive regime if the assumption of endogenous wages is taken seriously.     

Public goods provision,redistributive taxation,and wealth accumulation

This paper presents an extension of a static model of public goods provision with redistributional taxation, as described by Uler [Journal of Public Economics 93 (3–4), pp. 440–453], as a dynamic model of wealth accumulation. Intertemporal consumption and saving behavior strongly affect the relation between redistributive taxation and charitable contribution. Indeed, the analyses presented herein reveal that more patience (i.e. higher saving) engenders a lower redistributional tax rate. However, the optimal redistributive tax rate is not zero because redistributive taxation improves the efficiency of providing public goods that are not improved by balanced growth. This paper fills the gap separating static analysis and dynamic analysis, and generalizes the results presented by static analysis.     

When Redistribution Leads to Regressive Taxation

We introduce labor contracts in a framework of optimal redistribution: firms have some local market power and try to discriminate among heterogeneous workers. In this setting we show that if the firms have perfect information, i.e., they perfectly discriminate against workers and take all the surplus, the best tax function is flat. If firms have imperfect information, i.e., if they offer incentive contracts, then (under some assumptions) the best redistributive taxation is regressive.