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 politics of progressive income taxation with incentive effects

This paper studies majority voting over quadratic taxation and investigates under which conditions marginal progressivity emerges as a voting outcome. In our model with endogenous income, there is no majority (Condorcet) winning tax schedule. We then investigate less demanding political equilibrium concepts in order to see under which conditions the set of equilibria is composed only of progressive tax functions. We follow three strategies: (i) reduction of the policy space to the tax functions that are ideal for some voter; (ii) elimination of weakly dominated strategies and the use of mixed strategies in a standard Downsian two-party competition game; (iii) assumption that political parties interact repeatedly and care about the size of their majority. Although each approach captures a different aspect of political behavior, they point to the same (simulation-based) conclusion that progressivity is more likely to emerge for most distributions of abilities and that it is actually the only possible voting outcome if the distribution is sufficiently concentrated at the middle.     

The tradeoff between social insurance and aggregate fluctuations

Government programs that insure individuals against idiosyncratic risks, such as unemployment insurance, attempt to offset shocks that are obscured by behavioral variables. The resultant moral hazard reduces the efficiency of the insurance. When this feature is examined in a dynamic setting, the variance and duration of aggregate income fluctuations may be intensified by insurance.     

Consistent representative democracy

We study axioms which define “representative democracy” in an environment in which agents vote over a finite set of alternatives. We focus on a property that states that whether votes are aggregated directly or indirectly makes no difference. We call this property representative consistency. Representative consistency formalizes the idea that a voting rule should be immune to gerrymandering. We characterize the class of rules satisfying unanimity, anonymity, and representative consistency. We call these rules “partial priority rules.” A partial priority rule can be interpreted as a rule in which each agent can “veto” certain alternatives. We investigate the implications of imposing other axioms to the list specified above. We also study the partial priority rules in the context of specific economic models.     

The Costs of Implementing the Majority Principle: The Golden Voting Rule

In a context of constitutional choice of a voting rule, this paper presents an economic analysis of scoring rules that identifies the golden voting rule under the impartial culture assumption. This golden rule depends on the weights β and (1−β) assigned to two types of costs: the cost of majority decisiveness (‘tyranny’) and the cost of the ‘erosion’ in the majority principle. Our first main result establishes that in voting contexts where the number of voters n is typically considerably larger than the number of candidates k, the golden voting rule is the inverse plurality rule for almost any positive β. Irrespective of n and k, the golden voting rule is the inverse plurality rule if β ≥ 1/2 .. This hitherto almost unnoticed rule outperforms any other scoring rule in eliminating majority decisiveness. The golden voting rule is, however, the plurality rule, the most widely used voting rule that does not allow even the slightest ‘erosion’ in the majority principle, when β=0. Our second main result establishes that for sufficiently “small size” voting bodies, the set of potential golden rules consists at most of just three rules: the plurality rule, the Borda rule and the inverse plurality rule. On the one hand, this finding provides a new rationalization to the central role the former two rules play in practice and in the voting theory literature. On the other hand, it provides further support to the inverse plurality rule; not only that it is the golden rule in voting contexts, it also belongs, together with the plurality rule and the Borda method of counts, to the “exclusive” set of potential golden voting rules in small committees. We are indebted to Jim Buchanan, Amichai Glazer, Noa Nitzan, Ken Shepsle, and an anonymous referee for their useful comments.     

The redistributive roles of unemployment insurance and the dynamics of voting

Public unemployment insurance is analyzed as the majority voting equilibrium policy of a dynamic stochastic economy. Abstracting from incentive effects, we focus on redistribution. Some results are: because of the distribution of heterogeneous employment opportunities, public insurance may be democratically chosen even if complete private markets exist: and because of the dynamics, even when agents are intrinsically homogeneous, the equilibrium benefit level (or duration-benefit schedule) deviates from what has been described as optimal in the literature. The effects of differences in the average frequency or duration of unemployment on equilibrium taxes and benefits are investigated, with some unanticipated results.     

Campaign spending regulation in a model of redistributive politics

Summary. We consider a model in which parties that differ in perceived valence choose how to allocate electoral promises (money, pork-barrel projects) among voters. The party perceived to be less valent has a greater incentive to “sell out” to a favored minority and completely expropriate a fraction of the electorate. By reducing the difference in perceived valence, campaign-finance regulations may reduce the extent of the expropriation and achieve a more equitable political outcome. We analyze various instruments of campaign-finance regulation from this perspective.Received: 20 Februay 2003, Revised: 25 January 2005, JEL Classification Numbers: D72, H2.Nicolas Sahuguet: Correspondence toWe thank Alessandro Lizzeri, George Mailath, and Andrew Postlewaite for their comments. We also thank the editor Dan Kovenock and an anonymous referee. The second author is grateful to the National Science Foundation for financial support under grant SES-0078870.     

Social insurance for the elderly

We study the effects of retirement benefits provided by social insurance programs on consumption, portfolio choice, and retirement in a continuous-time theoretical model. We show that people tend to retire earlier with an increase in retirement social insurance benefits (SIBs), consistent with empirical evidence. We show also that people tend to increase savings before retirement in anticipation of increased retirement benefits, a counter-intuitive result. The response of risky investment with an increase in the SIBs is ambiguous, depending on parameter values. The overall social welfare will increase with an increase in SIBs if the balanced budget constraint is satisfied. We also investigate the effects of changes in the two streams of the SIBs (paid in perishable goods and cash) and the proportion of workers in entire population on social welfare.     

社会保险中的道德风险及其遏制

道德风险来自人的机会主义倾向，是给他人和社会带来不利后果的人为风险。道德风险在社会保险领域发生的频率最高、分布最广、造成损失最大、防范难度也最高。被保险人试图利用自己掌握的信息优势，在追求自身效益最大化的同时做出损害保险人利益的行为。道德风险在社会保险的所有项目上都存在相应的表现及危害。针对社会保险中道德风险产生的原因，应从完善社会保险立法、增强查处力度、设计约束与激励并重的机制、建立信息对称机制及诚信自律机制等方面遏制社会保险的道德风险。     

Experimental evidence on coverage choices and contract prices in the market for corporate insurance

In this paper, we present experimental evidence on the effect adverse selection has on coverage choices and pricing in corporate insurance markets. Two sets of experimental data, each generated by experiments utilizing a specific parameterization of a corporate insurance decision, are presented to gauge these effects. In the first, subject behavior conforms to a unique equilibrium in which high risk firms choose higher coverage and contracts are priced accordingly. Insurers act competitively and convergence to equilibrium behavior is marked. In the second set, there is little evidence that subject behavior is consistent with either of the two equilibrium outcomes supported by the experimental setting—pooling by fully insuring losses and pooling by self insuring. JEL Classification C90, G14, G22 Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s10683-006-9152-y.     

农民工城镇医疗保险与新型农村合作医疗的衔接

现阶段我国正加强社会保障的制度建设.在城镇,今后社会保障的一个重要内容是将农民工纳入社会保险,首先保障其大病(住院)医疗和工伤;在农村,正试点新型农村合作医疗,主要通过大病统筹的方式解决农民的医疗风险.农民工是一特殊群体,他们多数流动于城市和农村之间.他们是只参加城镇的社会医疗保险体系或新型农村合作医疗?抑或可以两者同时参加?本文作者根据大量的调查和我国社会保障制度的设计,提出了自己的观点:鉴于两者的保障程度有限,近期不宜作出硬性规定,两者的结合可以提高农民工医疗保障的程度.     

Health insurance and lifestyles

This article contributes to the discussion surrounding the existence of ex ante moral hazard and propitious selection in a voluntary private health insurance scenario. Moreover, it provides an estimation of the determinants of lifestyle choices and of private health insurance demand. A multivariate probit is estimated for health insurance demand and lifestyle decisions to take into account the potential endogeneity of these decisions. The results indicate that there is evidence of ex ante moral hazard in deciding to do sports and eating healthy snacks. Hence, no propitious selection has been found for these decisions. Another relevant result shows that there is no individual heterogeneity for the lifestyle choices, except for smoking, and private health insurance choice. Evidence from the results also supports the idea that there are nonobservable variables playing a role in the lifestyle decisions. These results provide some directions for policymakers, such as the promotion of precautionary behaviours and the use of implicit lifestyle drivers to promote healthy choices by people.     

新型农村社会养老保险基金管理模式探究

新型农村社会养老保险基金是国家为保障农村老年居民的基本生活、建立和完善社会保障制度而设立的专项基金。如何对此项基金实行有效监督和管理,以及在目前条件下投资运营,实现农村养老基金的保值增值,对新型农村社会养老保险制度的稳定、农村经济的可持续发展及农民生活水平的提高,都有着至关重要的作用。     

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。     

Mutual insurance for catastrophe hazards: Case of deposit insurance

Deposit insurance involves catastrophe risk because bank failures spike during a banking crisis. Although mutual insurance is ill-suited for catastrophe risk, the US government structures deposit insurance like a mutual company owned by policyholders. Furthermore, an intertemporal mispricing resulting from a dividend-surcharge arrangement produces several problems. Most importantly, it worsens moral hazard. Through dividends and surcharges, deposit insurance transfers the premium burden from high-risk banks to low-risk banks and in effect erodes the charter value of low-risk banks. In addition, high-risk banks taking catastrophe risk can outperform low-risk banks for many years in a row, putting pressures on managers of low-risk banks. Owing to these factors, an underpricing of catastrophe risk before its realization can ratchet up risk-taking by banks. Other problems with the intertemporal mispricing include making the banking business more procyclical, distorting the prices of banking products, and exposing taxpayers to asymmetric downside risk. To ensure fair competition and improve economic efficiency, the government should set the insurance premium based not on the realized loss but on the expected loss.     

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.     

The life insurance market: Asymmetric information revisited

This paper finds evidence for the presence of asymmetric information in the life insurance market, a conclusion contrasting with the existing literature. In particular, we find a significant and positive correlation between the decision to purchase life insurance and subsequent mortality, conditional on risk classification. Individuals who died within a 12-year time window after a base year were 19% more likely to have taken up life insurance in that base year than were those who survived the time window. Moreover, as might be expected when individuals have residual private information, we find that the earlier an individual died, the more likely she was to have initially bought insurance. The primary factor driving the difference between our and the prior literature's findings is that we focus on a sample of potential new buyers, rather than on the entire cross section, to address the sample selection problem induced by potential mortality differences between those with and those without coverage.     

Redistributive policies with heterogeneous social preferences of voters

There is growing evidence on the roles of fairness and other-regarding preferences as fundamental human motives. Call voters with fair preferences, as in Fehr and Schmidt (1999), fair-voters. By contrast, traditional political economy models are based on selfish-voters who derive utility solely from “own” payoff. In a general equilibrium model with endogenous labor supply, a mixture of fair and selfish voters choose optimal policy through majority voting. First, we show that majority voting produces a unique winner in pairwise contests over feasible policies (the Condorcet winner). Second, we show that a preference for greater fairness leads to greater redistribution. An increase in the number of fair voters can also lead to greater redistribution. Third, we show that in economies where the majority are selfish-voters, the decisive policy could be chosen by fair-voters, and vice versa. Fourth, while choosing labor supply, even fair voters behave exactly like selfish voters. We show how this apparently inconsistent behavior in different domains (voting and labor supply) can be rationalized within the model.     

黑龙江省不同农民群体的社会养老保险制度探析

完善农村社会养老保险制度是促进农村经济又好又快发展、实现城乡统筹发展、构建和谐社会的一项重要内容。随着农村经济发展和社会转型,农民群体逐渐分化,对农村社会养老保险制度设计提出了新的要求。黑龙江省现行的社会养老保险模式已不能适应这一现实,致使农村社会养老保险面临着巨大压力。根据农民的不同特点实行分类保障,构建新型农村社会养老保险制度,已是当务之急。     

Two separated effects of employer-provided health insurance on job mobility

We estimate the effect of employer-provided health insurance (EPHI) on job mobility via a dynamic model of joint employment and health insurance decision in the presence of uncertainty about wage rate and health status transitions. The model is based on a Markov decision process in which a hedonic wage approach provides an economic rationale for the different choices and health insurance serves as an input to the health production process. Including health transitions in the model helps us to understand how the availability of EPHI (positive job characteristic) and holding EPHI (the wage-health insurance trade-off) enter into the individuals’ decisions. The model is estimated using the 1999–2000 Medical Expenditure Panel Survey panel 4, and the results show that the ‘pure’ effects of holding EPHI are negligible, the ‘full’ effects of EPHI are significant and the degrees of the inefficiency vary between 14% and 25% across different states.