人口预期寿命与退休年龄

人口寿命的不断延长给中国养老事业带来越来越大的压力.文章在两期交叠世代模型的基础上引入退休,在市场完全竞争、充分就业和政府能够控制退休年龄的假设前提下,在个人、企业和政府的行为以及资本市场均衡的层面构建了一般均衡的模型框架,从社会计划者的角度发现福利最大化下的人口预期寿命变化和退休年龄是正相关的,并呈现出负反比例的函数形式.文章还基于参数估计和赋值模拟的方法,求解出了人口预期寿命与退休年龄的调整算法,并以此给出了两者间的调整对照表.根据计算的结果和预期的寿命,建议2030年前逐步将退休年龄延长至65岁.最后通过检验发现,如果不存在人口预期寿命和退休年龄之间的调整机制,在保持养老金收支平衡的前提下,预期寿命的延长将减少养老金的发放,并可能带来社会福利的损失.因此,在中国人口预期寿命不断延长的背景下,建议政府考虑建立人口预期寿命和退休年龄的调整机制.     

The Marginal Costs and Benefits of Redistributing Income and the Willingness to Pay for Status

The effect of status on aggregate welfare is ambiguous for marginal reforms that redistribute income. If average consumption falls, the change in relative consumption increases household utility but reinforces the decrease in household labor supply, raising welfare cost. For parameterizations of the model developed here, reforms which lower average consumption increase aggregate welfare. Numerical calculations show that status increases marginal welfare cost and marginal net benefit for a demogrant reform. Redistributing to high income households may increase aggregate welfare depending on the definition of average consumption and if the willingness to pay for status increases with income.     

Health investment, saving, and public policy

Abstract.  This paper develops an overlapping‐generations model in which agents invest in health to prolong life in both working and retirement periods. It explores how unfunded social security with or without health subsidies affects life expectancy, economic growth, and welfare. In particular, by extending life at a possible cost of capital accumulation, health subsidies and a pay‐as‐you‐go pension can improve welfare, especially in the short run. JEL classification: I12, J14, J18, O11     

Public pensions and growth

This paper investigates the relationship between the size of an unfunded public pension system and economic growth in an overlapping generation economy, in which altruistic parents finance the education of their children and leave bequests. Unlike the existing literature, we model intergenerational altruism by assuming that children's income during adulthood is an argument of parental utility. Unfunded public pensions can promote growth when families face liquidity constraints preventing them from investing optimally in the education of their children. We consider two alternative ways of financing a public pension system, either by levying social contributions in a lump-sum manner or in proportion to labour income. We find that there is no case for unfunded public pensions in economies where bequests are operative. By contrast, there exists a growth-maximising size of the public pension system in economies where bequests are not operative and individuals are sufficiently patient.     

Collective Annuities and Redistribution

This paper studies the role of alternative pension systems that offer collective annuities. The defining characteristic of collective annuities is that they do not depend on an individual's survival probabilities. We show that such a system may be welfare improving (with a utilitarian social welfare function) even when private annuity markets are perfect and when life expectancy and earning abilities are positively correlated (i.e., in a setting that is  a priori  biased against collective annuities). We first concentrate on linear pension systems and contrast two schemes: a pure contributory (Bismarckian) pension and a flat rate (Beveridgean) pension. We show that the case for collective annuities is stronger when they are associated with a flat pension system. Then we analyze nonlinear pension schemes. We show that the solution can be implemented by a pension scheme associated with annuities that reflect some degree of "collectiveness." Unlike under pure collective annuities, benefits do depend on life expectancy but to a lesser degree than with actuarially fair private annuities. In other words, the impact of survival probabilities is mitigated rather than completely neutralized.     

The Law of Comparative Advantage Without Social Utility Functions

This paper derives sufficient conditions under which the Law of Comparative Advantage and the General Law of Comparative Advantage are true when the preferences of the trading countries may not be represented by "well-behaved" social utility functions. It shows that in the neoclassical framework with convex technologies, profit maximization and Walras' Law, the laws of comparative advantage under a natural trade are still valid if either the General Law of Demand or the Weak Axiom of Revealed Preference holds, or if losers are compensated using lump-sum transfers or consumption taxes.     

Pension Reform during the Demographic Transition

The aim of this paper is to quantify the welfare effects of some currently discussed pension reform proposals in Germany. The analysis is based on an extended overlapping-generations model which accounts for intra-generational heterogeneity, rising life expectancy and declining fertility. Given a baseline path of the economy under the existing unfunded pension system, the model calculates the macroeconomic impact as well as the distributional and efficiency effects of various pension reform measures aimed at reducing the level of the future unfunded pension system. Simulations reveal that pension reforms cannot be evaluated solely in terms of inter- and intra-generational equity. Substantial efficiency gains or losses might arise if the linkage between contributions and benefits is improved or weakened.     

VOTING ON SOCIAL SECURITY WHEN LABOR SUPPLY IS ENDOGENOUS†

One of the puzzles in the political economic theory of unfunded pension systems is that middle-aged voters do not seem to advocate unlimited increases in the level of contributions and benefits if they take this decision to be valid forever. While the previous literature answered this question by pointing at borrowing restrictions, a more convincing explanation rests on the voters’understanding that future social security taxes will adversely affect future labor supply and thus the source from which their own pensions must be financed. This paper analyzes the validity of this explanation for two different types of pension systems, (a) the lump-sum benefits case, and (b) the case of fairness within cohorts.     

健康寿命研究的介绍与评述

随着人口迅速老龄化,一些国家都出现了在平均预期寿命提高的同时,人口健康状况下降的情况,即人活得长,并不一定活得健康。人们开始认识到:健康可以导致长寿,但长寿不一定就健康。因此,在测量生命长度(即数量)的同时,还要能够测量生命质量。健康寿命正是这样一个既可以测量生命数量也可以测量生命质量的指标。主要讨论测量健康寿命的意义;健康寿命的涵义和概念;有关健康寿命的理论假说;健康寿命的测量和计算方法;国际和国内健康寿命研究状况;以及健康寿命研究中存在的问题。     

Saving and retirement behavior under quasi-hyperbolic discounting

This paper investigates saving and retirement behavior using a quasi-hyperbolic discounting model with endogenous labor supply. The behavior of quasi-hyperbolic-discounting consumers is compared with optimal behavior, which is obtained under exponential discounting. The quasi-hyperbolic discounters, whether naïve or sophisticated, under-save and retire early compared with an exponential discounter, if and only if the present-biased marginal utility of future consumption decreases with stronger present bias. Logarithmic utility functions and constant-absolute-risk-aversion utility functions can both exhibit this property. In other words, quasi-hyperbolic discounting explains why, consistent with previous empirical studies, under-savers might also be early retirers. Under logarithmic utility, a wage tax and an interest subsidy can counteract the under-saving and early retirement and improve consumer welfare.     

Optimal Taxation when Consumers Have Endogenous Benchmark Levels of Consumption

I examine optimal taxes in an overlapping generations economy in which each consumer's utility depends on consumption relative to a weighted average of consumption by others (the benchmark level of consumption) as well as on the level of the consumer's own consumption. The socially optimal balanced growth path is characterized by the Modified Golden Rule and by a condition on the intergenerational allocation of consumption in each period. A competitive economy can be induced to attain the social optimum by a lump-sum pay-as-you-go social security system and a tax on capital income.     

Social indicators and comparisons of living standards

Construction of an international index of standards of living, incorporating social indicators and economic output, typically involves scaling and weighting procedures that lack welfare-economic foundations. Revealed preference axioms can be used to make quality-of-life comparisons if we can estimate the representative household's production technology for the social indicators. This method is applied to comparisons of gross domestic product (GDP) and life expectancy for 58 countries. Neither GDP rankings, nor the rankings of the Human Development Index (HDI), are consistent with the partial ordering of revealed preference. A method of constructing a utility-consistent index incorporating both consumption and life expectancy is suggested.     

Efficiency in overlapping generations economies with longevity choices and fair annuities

When individuals can influence their life-expectancies and save in annuities, suboptimal savings result from the lack of incentives to choose the optimal longevity, even when annuity returns can be made contingent to longevity-related choices. Specifically, the golden rule steady state maximizing the representative agent utility cannot be attained as a competitive equilibrium under laissez-faire, even with actuarially fair annuities contingent to longevity-enhancing choices. In order to decentralize through markets the golden rule, longevity-enhancing expenditures need to be taxed if the steady state old-age consumption exceeds the annuitized capital return, and subsidized otherwise—the government budget being balanced through lump-sum transfers or taxes. Interestingly, with positive population growth the expected net contribution is negative when longevity-enhancing expenditures are taxed, and positive when subsidized.     

Social Desirability of Earnings Tests

Abstract. In many countries, pension systems involve some form of earnings test; i.e. an individual's benefits are reduced if he has labor income. This paper examines whether or not such earnings tests emerge when pension system and income tax are optimally designed. We use a simple model with individuals differing both in productivity and in their health status. The working life of an individual has two 'endings': an official retirement age at which he starts drawing pension benefits (while possibly supplementing them with some labor income) and an effective age of retirement at which professional activity is completely given up. Weekly work time is endogenous, but constant in the period before official retirement and again constant (but possibly at a different level), after official retirement. Earnings tests mean that earnings are subject to a higher tax after official retirement than before. We show under which conditions earnings tests emerge both under a linear and under a non-linear tax scheme. In particular, we show that earnings tests will occur if heterogeneities in health or productivity are more significant after official retirement than before.     

CHANGING PENSION POLICY AND THE AGING OF AMERICA

The recently enacted Tax Reform Act of 1986 contains a number of pension policy provisions including faster vesting for private-sector, single-employer pension plans and imposing tax penalties on preretirement pension plan distributions that are not saved until retirement age. Since pensions are a long-term commitment, the impact of pension policy changes may not be fully realized for a number of years. For that reason, the effects of the Tax Reform Act's pension provisions are investigated using both short-run and long-run simulation models. Faster vesting would immediately entitle an additional 1.9 million pension plan participants to pension benefits at retirement. This increase would not, however, be translated directly into significant gains in pension recipiency for workers currently in their 50s. Nevertheless, by the time the baby boom generation retires, faster vesting and lump-sum penalties could provide more retirees with pensions and increase the standard of living of pension recipients.     

Optimal accident compensation schemes

This paper considers the way in which accident compensation is offered as insurance against personal injury due to accidents. We begin by setting up a simple microeconomic model in which accident compensation schemes can be studied. Using this model, the accident compensation scheme that maximizes the expected utility of the insured for a given expected outlay of the scheme (that is, for a budget constraint for the insurer) is characterized. We show that, in order for the optimal schedule of indemnities to be increasing (more severe accidents lead to greater compensation) then, contrary to what has been assumed in the literature, the marginal utility of wealth must be decreasing in health. In particular, if the marginal utility of wealth is non-decreasing in health, then an optimal indemnity schedule cannot provide full compensation, in the sense that utility in each state is a constant. Financial support from Secretaría de Estado de Universidades e Investigación del Ministerio de Educación y Ciencia is gratefully acknowledged by F. J. Vázquez.     

Seigniorage and public good in an OLG model with cash-in-advance constraints

This paper is a contribution to the theory of the optimal monetary policy in overlapping generations models with a cash-in-advance constraint applying on old age consumption purchases. We are particularly interested in the study of seigniorage when the latter is used to finance public goods valued by consumers. Assuming that a public good enters the utility function and the existence of cash-in-advance constraints, we find a Laffer curve of seigniorage at steady-state. We also analyze the dynamic optimal monetary policy when the government maximizes an intertemporal social welfare function and can only resort to seigniorage to finance the purchases of the public good. We show that the optimal rate of money growth may be strictly higher than the one which maximizes steady-state seigniorage: the optimal amount of seigniorage may lie on the decreasing part of the Laffer curve of seigniorage. We finally suppose that the government can use lump-sum taxes in addition to seigniorage. Then, the Friedman rule prevails and public expenditures are only financed through lump-sum taxes.     

Efficiency in an Economy with Fixed Costs

It is by now well known that in an economy with increasing returns, first-best efficiency may be impossible to attain through an equilibrium concept based on market prices, even if firms are regulated to follow marginal cost pricing. We examine the efficiency issue in a special but important class of economies in which the only source of nonconvexities is the presence of fixed costs. Even in this context, it is possible that none of the equilibria based on marginal cost pricing are efficient (unless additional, strong assumptions are made). We argue that available results on the existence of an efficient two-part tariff equilibrium rely on very strong assumptions, and we provide a positive result using a weak surplus condition. Our approach can also be used to establish the existence of an efficient marginal cost pricing equilibrium with endogenously chosen lump-sum taxes if the initial endowment is efficient in the economy without the production technology.     

A Theory of Brinkmanship, Conflicts, and Commitments

Many conflicts and negotiations can be viewed as dynamic gamesin which parties have no commitment power. In our model, a potentialaggressor demands concessions from a weaker party by threateningwar. The absence of commitment makes a continuous stream oftransfers a more effective appeasement strategy than a lump-sumtransfer. As long as both sides have constant marginal utilityof consumption, it is possible to construct a self-enforcingpeace agreement even if transfers shift the balance of power.When marginal utility of consumption is decreasing, a self-enforcingpeace agreement may not be feasible. The bargaining power ofthe potential aggressor increases dramatically if she is ableto make probabilistic threats, for example, by taking an observableaction that leads to war with a positive probability. This "brinkmanshipstrategy" allows a blackmailer to extract a positive streamof payments from the victim, even if carrying out the threatis harmful to both parties. Our results are applicable to environmentsranging from diplomacy to negotiations within or among firmsand are aimed to bring together "parallel" investigations inthe nature of commitment in economics and political science.