A welfare analysis of social security in a dynastic framework*

In this article, we study the welfare effects of unfunded social security in a general equilibrium model populated with overlapping generations of altruistic individuals that differ in lifetime expectancy and earnings ability. Contrary to previous research, our results indicate that steady‐state welfare increases with social security for most households, although by very different amounts. This result is mainly due to two factors. First, the presence of two‐sided altruism significantly mitigates the crowding out effect of unfunded social security. Second, ability shocks and uncertain lifetimes generate significant heterogeneity among households to yield different induced preferences for social security.     

A life cycle analysis of social security

Summary We develop an applied general equilibrium model to examine the optimal social security replacement rate and the welfare benefits associated with it. Our setup consists of overlapping generations of 65-period lived individuals facing mortality risk and individual income risk. Private credit markets, including markets for private annuities, are closed by assumption. Unlike previous analyses, we find that an unfunded social security system may well enhance economic welfare. In our benchmark economy, the optimal social security replacement rate is 30%, and an empirically more plausible replacement rate of 60% raises welfare compared with an economy with no social security system.We would like to thank Andy Atkeson, V. V. Chari, Steve Davis, Paul Evans, Lars Hansen, Tim Kehoe, Nobu Kiyotaki, Ed Prescott, José-Victor Ríos-Rull, Richard Rogerson, Tom Sargent, Nancy Stokey, Dick Sweeney, Robert Townsend, and the participants of the NBER Economic Fluctuations Small Group Workshop on Micro and Macro Perspectives on the Aggregate Labor Market in Palo Alto, the NBER General Equilibrium Theory Conference in Minneapolis, the Money and Banking Workshop at the University of Chicago, and the NBER Summer Institute. An earlier version of this paper was titled A Dynamic Stochastic General Equilibrium Analysis of Social Security. This material is based upon work supported by the National Science Foundation under Grant No. SES-9210291. We also thank the Minnesota and San Diego Supercomputer Centers for their support.     

Temptation and social security in a dynastic framework

We investigate welfare and aggregate implications of a pay-as-you-go (PAYG) social security system in a dynastic framework in which individuals have self-control problems. The presence of self-control problems induces individuals to save less because of their urge for temptation towards current consumption. Individuals' efforts to balance between the short-term urge for temptation and the long-term commitment for consumption smoothing result in self-control costs. In this environment PAYG social security works as a self-control cost reducing device. In contrast, the presence of altruism induces individuals to save more. This in turn mitigates the adverse effects of self-control problems and PAYG social security on savings but magnifies the self-control costs. We find that in our environment the adverse welfare effects of a PAYG system are further mitigated relative to the environments that incorporate altruism and self control issues separately. However, the level of mitigation is quite modest.     

A life-cycle analysis of social security with housing

This paper incorporates two features of housing in a life-cycle analysis of social security: housing as a durable good and housing market frictions. We find that both housing quantities and homeownership rates respond strongly to eliminating social security. Accordingly, the aggregate impacts of this policy reform are significantly larger in an economy with explicit housing choices than in a standard life-cycle economy. Our analysis shows that the key mechanism behind these results is the substitution effects of a change in interest rates and, thus, the price of housing services on the choice of nondurable consumption versus housing services.     

中国残疾人社会保障体系框架设计

作为社会弱势群体之一,中国残疾人群的基本生存状况令人担忧,迫切需要健全的残疾人社会保障体系来维护基本权益。利用2006年中国第二次全国残疾人抽样调查数据,描述了残疾人群收入贫困、就业困难、教育、医疗服务、康复等基本需求不能得到满足的生存状况,就此提出建立“多支柱、梯度扶助”式残疾人社会保障体系的框架设计。     

关于社保基金监管框架的思考

监管在广义上是指政府对企业活动的控制,具体来说,它是指政府专业管理部门或政府授权的行政执法机构依法对市场交易行为、市场主体竞争行为实行监督管理,维护市场运行秩序的管理行为.     

A positive theory of social security

In this paper I make two points. First, I argue that social security programs around the world link public pensions to retirement: people do not lose their pensions if they make a million dollars a year in the stock market, but they do confront marginal tax rates of up to 100 percent if they choose to work. Second, after arguing that most existing theories cannot explain this fact, I construct a positive theory that is consistent with it. The main idea is that pensions are a means to induce retirement—that is, to buy the elderly out of the labor force because aggregate output is higher if the elderly do not work. This is modeled through positive externalities in the average stock of human capital: because skills depreciate with age, the elderly have lower-than-average skill and, as a result, have a negative effect on the productivity of the young. When the difference between the skill level of the young and that of the old is large enough, aggregate output in an economy where the elderly do not work is higher. Retirement is desirable in this case, and social security transfers are the means by which such retirement is induced. The theory developed in this paper is also shown to be consistent with a number of other regularities documented in Section 1.     

社会保障的新理念与中国农民扶持性社会保障体制

中国的市场化改革使广大的中国农民直接暴露在现代市场经济风险下,而家庭联产承包制的实施又使改革开放前与计划经济体制相适应的保障体制无法运转,这样,中国广大农民成为了现代市场经济中最没有保障的弱势群体。因此,建立农民社会保障体系的意义重大。中国农民社会保障体制迟迟没有建立的原因有二:其一,传统社会保障理念仅考虑到其工具价值,忽视了其目的价值;其二,农民的组织化程度低,导致他们在社会利益分割过程中没有谈判地位。从建立农民社会保障体制的双重价值出发,建立保障农民生存权和基本发展权的农民扶持性社会保障体制具有重要意义。     

浅析新农村的社会保障问题

社会保障是构建社会主义和谐社会的一项基础性制度建设,对调节收入分配、促进社会公平具有重要作用.本文从理论和实践的结合上,剖析了当前我国新农村建设中社会保障方面存在的根本性问题,同时对建设和完善符合我国国情的农村社会保障体系的发展思路进行了探讨.     

Welfare and comparative statics implications of fair social security : A steady-state analysis

This paper examines the steady-state welfare and comparative statics implications of fair social security in an overlapping generations model with uncertain lifetime. The model is designed to capture the effects of lifetime uncertainty extending over the individual's entire lifespan, the effects of intentional and unintentional bequests, and the effects of the earning profile. He shows that the welfare effects depend on the size of the benefits and the structure of the social security tax. In particular, even fair social security may have negative welfare implications if the underlying tax structure is ill-designed. Some comparative statics implications are analyzed.     

浅析新农村的社会保障问题

社会保障是构建社会主义和谐社会的一项基础性制度建设,对调节收入分配、促进社会公平具有重要作用。本文从理论和实践的结合上,剖析了当前我国新农村建设中社会保障方面存在的根本性问题,同时对建设和完善符合我国国情的农村社会保障体系的发展思路进行了探讨。     

A quantitative theory of social security without commitment

This paper investigates the determination of social security within a general equilibrium, overlapping-generations model where agents live for many periods, and replacement rates are determined through voting in each period by forward looking agents. The distinctive feature is the study of Markov equilibrium policy outcomes which do not rest on a commitment mechanism. Versions of the model are calibrated to the US economic, policy, and demographic conditions. Even in the absence of commitment, the policy preferences of tax-paying working-age voters sustain a positive level of retirement benefits. This follows because the current choices about social security will have, at the time when the current voters will retire, a positive impact on the political support for social security and on the returns to savings. On the other hand, the projected decline in the U.S. population growth rate causes the replacement rate and the tax rate to decline. This quantitative response without commitment differs from that in the case when policies are committed at time zero.     

On myopia as rationale for social security

It has been argued that “paternalistically motivated forced savings constitutes an important, and to some the most important, rationale for social security retirement systems.” This paper revisits the role played by myopia in generating a theoretical rationale for pay-as-you-go (PAYG) social security in dynamically efficient economies. If the competing asset is linear storage and myopic agents are allowed to borrow against future pension benefits, there is no welfare-rationale for PAYG pensions. Sufficiently strong myopia may justify such pensions only if agents cannot borrow against their future pension, but then they are at a zero-saving corner. With enough myopia, co-existence of positive optimal pensions and positive private saving is possible if the return to saving declines with saving, as in a model with a neoclassical technology.     

我国社会保障立法刍议

世纪之初,党和国家提出把做好社会保障作为当前全国的一项重要任务,争取用五年时间,初步建立起与社会主义市场经济体制相适应的社会保障体系。本文从社会保障的定义,内容以及对社会进步的作用说起,分析当前我国在社会保障立法方面存在的主要问题,并且针对这些问题建设性地提出一些解决方法。尤其是重点探讨了社会保险法在立法上的若干问题。     

Search for financial returns and social security privatization

I develop a general equilibrium model in which the quality of household financial decisions is endogenously determined by the incentives to exert effort in learning about financial opportunities. The model generates predictions for asset market participation and returns across households. Moreover, search for financial returns enables the model to generate a more skewed equilibrium wealth distribution. In this context, social security privatization affects household search effort, asset market participation and the competitiveness of the asset market. Privatization reduces average welfare and this reduction is somewhat magnified by the search friction. While some have suggested that household decision making could be important for the consequences of privatization, my analysis does not bear this out.     

Differential mortality and social security

Abstract This paper studies the normative problem of redistribution between individuals who differ in their lifespans. We discuss aspects related to the objective function and argue that aversion to multiperiod inequality should be taken into account. Then, we study the properties of the social optimum both with full information and with asymmetric information. We highlight the role of aversion to multiperiod inequality and show that it has substantial consequences on the design of Social Security schemes. In particular, we show that for a low (resp. high) aversion to multiperiod inequality, a negative (resp. positive) implicit tax rate on continued activity is desirable.     

Auctions for social lending: A theoretical analysis

Prosper, today the second largest social lending marketplace with nearly 1.5 million members and $380 million in funded loans, employed an auction mechanism amongst lenders to finance each borrower's loan until 2010. Given that a basic premise of social lending is cheap loans for borrowers, how does the Prosper auction do in terms of the borrower's payment, when lenders are strategic agents with private true interest rates? We first analyze the Prosper auction as a game of complete information and fully characterize its Nash equilibria, and show that the uniform-price Prosper mechanism, while simple, can lead to much larger payments for the borrower than the VCG mechanism. We next compare the Prosper mechanism against the borrower-optimal auction in an incomplete information setting, and conclude by examining the Prosper mechanism when modeled as a dynamic auction, and provide tight bounds on the price for a general class of bidding strategies.     

Funded social security and economic growth

This paper investigates the relationship between economic growth and a fully funded social security system in an overlapping generations model with family altruism. It is shown that funded social security may harm growth if there are operative bequests within the family.     

Sustainable social security: Four options

Four options to make the social security sustainable under the coming demographic shift are presented; increase payroll taxes by 6 percentage points, reduce replacement rates by one-third, raise the normal retirement age to 73, or means-test the benefits and reduce them in income. The paper accounts for labor supply at both intensive and extensive margins and analyzes welfare effects across agents that differ in age, wealth and cohorts. While the four policies all achieve the same goal, economic outcomes differ significantly. Options to curtail benefits encourage own savings and capital accumulation, while the payroll tax increase and the means-test reduce work effort. Future generations prefer options to reduce benefits, but current generations prefer to finance the transition with payroll taxes.