Takeup,social multipliers and optimal social insurance

This paper examines the optimal provision of unemployment insurance (UI) in a framework that accounts for behavioral responses along both the intensive and extensive margins. Two formulations of takeup are considered: in the first, individuals face a takeup cost that is exogenous; in the second, the cost depends endogenously on the takeup rate. Such endogenous costs to takeup lead to a social multiplier, a reduced-form parameter summarizing the strength of social interactions. This paper derives a formula for the optimal replacement rate in terms of the takeup and duration elasticities, and the social multiplier. The formula is applied by estimating the social multiplier using policy variation in UI benefit levels. The results suggest that social multiplier effects account for 35% of the total effect of UI on takeup and yield an optimal replacement rate around 60% of pre-unemployment wages, 20% higher than previous estimates.     

Moral hazard,adverse selection,and the optimal provision of social insurance

The single-period social insurance model of Diamond and Mirrlees is extended to allow for a diversity of types (in the probability of becoming disabled). When individual type is observable, the utilitarian optimum has both consumption when working and disability benefits increasing with the probability of disability. When type is not observable (adverse selection is present), the optimum is a single ‘pooling’ policy over a wide range of welfare weights which includes the utilitarian case. These results also provide insights into the potential distributional effects of moral hazard and the ways moral hazard and adverse selection problems may interact.     

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     

A model of social insurance with variable retirement

Models are studied, in which ability to supply labour is affected by a random variable (health) not observable by government. When ill-health strikes, the consumer must retire, but he may choose to retire in any case. Optimal social insurance policies are found for one-period, two- period, and continuous-time models. It is found that, under plausible conditions, at the optimums consumers are indifferent whether to work or not, but do work when able. Insurance contributions decrease with age, and insurance benefits increase with age of retirement. It is desirable to prevent private saving. Some comments on the U.S. Social Security system are added.     

Social insurance and social justice—Another look at the antipoverty effects of social insurance programs

This paper analyzes social insurance programs in the United States to determine if they support the principles of social justice, with special emphasis on the principle of preferential treatment of the poor. The paper also examines the antipoverty effects of social insurance programs. The major conclusions are the following: (1) social insurance programs generally are consistent with the principles of social justice, but parts of certain programs clearly violate the norms of social justice; (2) social insurance programs are especially powerful in reducing the poverty rate and poverty gap for the elderly, but are generally ineffective in reducing the poverty rate for single-parent families with related children under age 18; (3) social insurance programs have only a minor impact in reducing the poverty rate among married-couple families with related children under age 18; and (4) although the Social Security payroll results in a small increase in the poverty rate, social insurance programs are especially effective in reducing income inequality.     

A bioeconomic model for estimating the optimal level of deer and tag sales

This paper presents a dynamic model that determines the optimal number of deer hunting permit sales, subject to the objective of maximizing the discounted economic benefits stream from both the consumptive and nonconsumptive uses of deer. This bioeconomic model integrates economic benefits estimated using the dichotomous choice contingent valuation method with biological growth constraints on deer. Using a hunting zone in California as a case study, the model found that the optimal levels of buck hunting permits sold should change on a rotational basis over time and that the current practice of not selling doe hunting permits for that zone is non optimal.     

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.     

Uncertainty and the optimal level of specialization

Using a two-sector one-factor comparative-advantage-based trade model under uncertainty, we show that (1) to specialize according to comparative advantages may be sub-optimal in a multi-period setting; (2) there are conditions under which, even if agents are risk-neutral, the decentralized solution is inefficient and characterized by overspecialization.     

On the optimal design of insurance contracts with the restriction of equity risk

This paper focuses on the optimal design of insurance contracts with the restriction of equity risk by Arrow's optimal insurance model [2] and Zhou's optimal insurance model [4]. The insured aims to maximize his/her expected utility of terminal wealth, under the constraint that the insurer wishes to control his/her risk. We establish an optimal insurance model that restrains underwriting risk and investment risk simultaneously. We solve this problem and obtain the results which improve and extend the results given by Arrow [2] and Zhou [4].     

A general impossibility result on strategy-proof social choice hyperfunctions

A social choice hyperfunction picks a non-empty set of alternatives at each admissible preference profile over sets of alternatives. We analyze the manipulability of social choice hyperfunctions. We identify a domain D^λ of lexicographic orderings which exhibits an impossibility of the Gibbard–Satterthwaite type. Moreover, this impossibility is inherited by all well-known superdomains of D^λ. As most of the standard extension axioms induce superdomains of D^λ while social choice correspondences are particular social choice hyperfunctions, we are able to generalize many impossibility results in the literature.     

Understanding the welfare effects of unemployment insurance policy in general equilibrium

This paper analyzes the welfare effects of unemployment insurance reforms in a general equilibrium incomplete market model. In particular, it decomposes the total welfare effect for each individual into different factors. I consider a model where the consumers face an uninsurable unemployment risk, can save in an interest-bearing asset, and are subject to a borrowing constraint. The labor market is modeled using a Diamond–Mortensen–Pissarides style search and matching model. The decomposition exercises reveal how each factor contributes to the heterogeneity of welfare effects among different consumers.     

Path dependence of the general price level: A value theoretic analysis

The paper examines path dependence of price indexes, a problem that has become acute after international adoption of chain indexes for price and volume changes in the SNA93. Path dependence is an old issue of index numbers, and has been in the way of using chain indexes ever since their invention. The paper accepts chaining at its start, and tries to develop a sound deflation procedure from there. In this analysis path dependence is less an issue of appropriate formalization of a given concept, the traditional approach in index number theory, but rather a problem of developing an interpretation to a given and now worldwide recommended statistical practice. The key issue is found in the fact that money is not only the standard means of payment, concerning central banks, but also the standard of value in an economy, a feature that bears directly on the compilation of price indexes and national accounts. As a result, a chained weighted index is shown to be path independent, if it is interpreted as a change not of prices, but of the unit of account in which prices are expressed.     

The effect of non-employment-based health insurance program on firm's offering of health insurance: Evidence from the social health insurance system in China

To achieve universal health insurance coverage, many developing countries have established a segmented health insurance system, which contains separate programs for workers with formal employment and residents without formal employment. A potential concern with such a segmented system is that the establishment of a non-employment-based insurance program may generate a disincentive for firms to provide health insurance benefits to workers. In this study, we empirically examine this crowd-out effect of a non-employment-based insurance program, the Urban Residents Basic Medical Insurance (URBMI), in China. Exploiting city-by-year variations in the roll-out process of the program and utilizing a unique administrative dataset on Chinese firms, we find that the enactment of URBMI reduced a firm's offering of an employment-based health insurance program by a statistically significant 0.94-1.29 percentage point. This crowd-out effect was stronger among domestic private firms, new firms, and firms that are individual-owned.     

中国失业社会保险制度改革探讨

当前,我国的失业社会保险制度出现了统筹层次低、覆盖面较窄、促进再就业的功能弱化等问题,需要通过适时提高统筹层次、扩大企业社会保险的覆盖面和完善失业社会保险促进再就业等措施进一步改革完善。     

Some general results on the metric rationalization for social decision rules

The purpose of this paper is twofold. First, to provide a transparent characterization of the family of metrizable social decision rules. Second, to provide the necessary and sufficient conditions for a reasonable metric rationalization. Theorem 1 establishes that the class of metrizable social decision rules is uniquely characterized by a variant of the well-known Pareto condition. Theorem 2 establishes that positional rules can be characterized in terms of a special class of additively decomposable quasi-metric rationalizations. Theorem 3 characterizes strong positional rules in terms of reasonable metric rationalizations.     

Industrial subsidy policy and the optimal level of specialization

Despite compelling rationale based on the theory of comparative advantage for free trade, many countries adopt restrictive trade practices. In this paper we investigate this puzzle in a stylized two-country two-good Ricardian model of international trade. Governments can offer protection to domestic industries via industrial subsidy policy in this model. We prove the existence of a Nash equilibrium in the two-player game where industries choose the level of specialization. We determine the necessary conditions for complete specialization in (a) the free-trade regime; and (b) the protectionist regime implemented through industrial subsidy policy. Our results show that if the government intends to promote complete specialization, then a high degree of comparative advantage and a large elasticity of substitution between export and import goods are required. Empirical evidence on these two parameters indicate that complete specialization is unlikely to survive in the protectionist regime.