The old age security hypothesis and optimal population growth

The old age security approach is used to study the relationship between the rate of growth of the population and capital accumulation, within a Samuelson-Diamond overlapping generations framework. It is shown that a decentralized economy will fail, in general, to achieve the Pareto optimal path. However, a pay-as-you-go social security scheme in which the old get transfers which are proportional to the number of their children may restore optimality. On the other hand, child support systems or subsidies to capital can guarantee the optimal capital: labor ratio, but not the optimal population growth rate, while a lump sum social security system can guarantee the optimal population growth rate, but not the optimal capital: labor ratio. Finally, in a monetary economy any policy aimed at correcting the interest rate will restore full optimality.An earlier version of this paper was written during a visit to the University of California, San Diego. The paper benefited from the comments of two referees.     

中国城镇居民家庭储蓄水平队列效应分析

利用中国家庭收入调查（ CHIP）数据对城镇居民家庭的储蓄率进行了队列效应的实证研究。分析结果表明,属于不同队列的城镇家庭在储蓄水平上都呈现出相似的“U”型年龄分布,即中年家庭（40－50岁）储蓄率低,年轻家庭（20－40岁）和退休家庭储蓄率较高,这一现象与其他国家的实证研究结果有显著不同。本文认为,中国城镇居民储蓄率的“U”型年龄分布主要是由人口与经济的高速增长带来的：人口高速增长带来的队列规模效应使得面对更大竞争压力的年轻人口储蓄率较高,而经济水平持续增长带来的消费水平增长预期使得接近退休家庭储蓄水平重新上升。     

养老保险收支平衡及其影响因素分析

养老保险能否顺利运作和发育 ,基本养老保险金的收支是否平衡至关重要。给定目标期间的养老金收支平衡模型为 :∑nj =1c× ∑b- 1i =ax( i j)× w( j) -∑w- 1i =bx( i j)× Q( j)× ( 1 r) n- j =0 ,影响养老金收支平衡的因素较多 ,除缴费率、替代比例、退休年龄、工资增长率和养老金增值率、通货膨胀、养老金计发办法等基本因素外 ,人口迁移、失业等也会对养老金收支平衡产生影响     

Demographic Dividend,Population Aging and Raising the Retirement Age

China’s low fertility combined with increase in average life expectancy is leading to disappearing demographic dividend and population aging crisis. In this case, we may have a policy choice to raise the retirement age. Because the disappearing of demographic dividend gradually and the reversal of labor supply and demand may be the driving force of raising the retirement age, and the payment crisis of pension system which caused by the population aging may be the pulling force of raising the retirement age. If we consider the impact of this policy on urban employment and the laborheterogeneity in current conditions, we should carry out the practical policy which raise the retirement age slowly progressive and gradually.     

Population growth,age structure,and age-specific productivity

Motivated by empirical evidence that fluctuations in age structure affect relative wages across age groups, this paper asks whether there is a steady-state age distribution that maximizes the lifetime wages of a representative worker. The paper proves the surprising result that in a pure labor economy with any constant returns technology, a uniform age distribution minimizes lifetime wages. Skewed age distributions, generated by either positive or negative population growth rates, generate unambiguously higher lifetime wages than a stationary population, in spite of possible reductions in per capita output in every period. The presence of non-labor factors complicates, but does not necessarily reverse, this result. The paper relates the beneficial effects of higher rates of population growth on lifetime wages in a pure labor economy with imperfect substitutability across age groups to the benefits of population growth that appear in overlapping-generation consumption loan models with intergenerational transfers.A previous version of this paper was presented at the Economic Demography Workshop at the 1988 meetings of the Population Association of America. Helpful comments from Mark Berger, Theodore Bergstrom, Ronald Lee, Hal Varian, and Robert Willis are acknowledged.     

General situation and characteristics of the population of the Yemen Arab Republic]

The Yemen Arab Republic conducted a national census on February 1, 1975 and collected accurate and useful information for population research. Such information can be used to understand various factors in this country's development process and to set up a longterm plan for the country's economic development. According to this census, the total population of the country was 4,705,337. About 54.4% of its population was under the age of 16, and the average age for the population was 16. This young age population structure shows that the number of people who need employment is high, and the pressure on social and economic development is strong. Because of a poor living standard and backward health care, the birthrate and death rate have remained very high, and economic growth has been very slow. Because of the poor geographical condition, the distribution of population in the country is rather scattered. Every residential area has an average population of less than 83 persons, and this is a great obstacle in the country's socioeconomic development. The cultural level and education remain very backward, and the illiteracy rate is high. The illiteracy rate among women is 97.6%. Most women do not participate in social labor. In the labor market, the percentage of underage workers is extremely high. Many young children have to work to support themselves because of the backward economy and poor living conditions. All these are obstacles to this country's economic development.     

Pension reform, employment by age, and long-run growth

We study the effects of pension reform on hours worked by three active generations, education of the young, the retirement decision of older workers, and aggregate growth in a four-period OLG model. The model explains important facts well for many OECD countries. Our simulation results prefer an intelligent pay-as-you-go system above a fully funded private system. Positive effects on employment and growth are the strongest when the pay-as-you-go system includes a tight link between individual labor income and the pension, and when it attaches a high weight to labor income earned as an older worker to compute the pension assessment base.     

Pension reform and labor market incentives

This paper investigates how parametric reform in a pay-as-you-go pension system with a tax–benefit link affects retirement and work incentives of prime-age workers. We find that postponed retirement tends to harm incentives of prime-age workers in the presence of a tax–benefit link, thereby creating a policy trade-off in stimulating aggregate labor supply. We show how several popular reform scenarios are geared either towards young or old workers or, indeed, both groups under appropriate conditions. We characterize the excess burden of pension insurance and show how it depends on the supply elasticities of both decision margins and the effective tax rates.     

Population dynamics and life-cycle consumption

This paper presents a model where aggregate consumption depends on both the level of wealth and the age structure of population. The explicit consideration of an endogenous rate of time preference permits to analyze the important role of population ageing as a determinant of aggregate saving. Received: 23 October 2001/Accepted: 13 February 2002 I would like to thank an anonymous referee for his comments. Financial support from CNR and MURST is gratefully acknowledged. Responsible editor: Alessandro Cigno.     

Does time preference change with age?

This study looks at compensating differentials in the National Longitudinal Survey of Youth (NLSY) to derive estimates of the levels of time preference for labor force participants in each of 15 waves of data from 1979 to 1994. With these estimates the evolution of time preference over the life course is described. Future utility among labor force participants appears to be valued more highly by subjects who are older, more schooled, white, or male. Controlling for schooling level, a higher IQ is associated with a preference for more immediate rewards.If social rates of time preference are correlated with individual rates of time preference then population aging could create intergenerational asymmetries in the social rate of time preference.This phenomenon could make the optimal investments of young populations appear selfish to future generations that are older.Support from Hopkins Population Center (R24) is gratefully acknowledged. I am thankful for helpful comments received from Jim Burgess, Mike Grossman, Bruce Hamilton, Fritz Laux, Athanasios Orphanides, Katie Roche, and Eric Slade. All errors are my own. Responsible editor: Alessandro Cigno.     

Population growth and social security financing

By allowing the population growth to be flexible, this paper analyzes the effect of a tax reform that involves an introduction of consumption taxation for social security financing. It is found that population growth and labor supply play an important role in determining the effect of the tax reform. If population growth and labor supply are exogenous, then an introduction of a consumption tax for social security financing, with the payroll tax rate being endogenous, decreases the interest rate and increases capital accumulation. However, if population growth and labor supply are endogenous, then an introduction of a consumption tax for social security financing increases the interest rate and reduces capital accumulation. Received: 26 February 2001/Accepted: 26 August 2001     

Capital accumulation,endogenous population growth,and Easterlin cycles

In this paper we attempt to explain the occurrence of population cycles in industrialised economies where the birth rate depends on the difference between the actual and the expected consumption rate. This model of an endogenously growing population brings together Easterlin's idea of an adapting aspiration level with the neoclassical optimal growth paradigm. It is shown that in this highly aggregated demo-economic system (i.e., without inclusion of the age structure of a population) swings both in the economic and demographic variables may exist. The reason behind this strange optimal behaviour is identified to be an intertemporal substitution effect between current and future levels of consumption.We wish to thank A. Novak for helpful assistance and an anonymous referee for useful comments. Financial support by the Austrian Science Foundation under contract No. P6601 is acknowledged.     

Assessing Parfit’s Repugnant Conclusion within a canonical endogenous growth set-up

Parfit’s Repugnant Conclusion stipulates that under total utilitarianism, it might be optimal to choose increasing population size while consumption per capita goes to zero. We evaluate this claim within a canonical AK model with endogenous population size and a reduced form relationship between demographic and economic growth. First we characterize the optimal solution paths for any capital dilution function. Second, we prove that while the Repugnant Conclusion can never occur for realistic values of intertemporal substitution in the traditional linear dilution model, it does occur when population growth is linked to economic growth via an inverted U-shaped relationship.     

延迟退休的影响效果分析

近年来．延迟退休的问题引发了学术界和社会大众的广泛讨论。本文将研究视点放在提高退休年龄对养老金支付和劳动力就业的影响效果方面。通过构建不同的计量模型,实际估算了延迟退休对养老保险基金收支变化的影响．以及对劳动力市场的就业挤出效应。结果发现：提高法定退休年龄对养老金缺口存在一定的补偿效应。但从短期来看效果有限;而对就业总量的确将产生挤出效应。并发现,老年人就业岗位与青年人就业岗位之间存在替代性,也就是说延迟退休将严重影响青年人的就业。因此建议政府要慎重考虑并只能在适当的时机推动延迟退休。     

Assessing the effects of an early retirement program

We investigate induced retirement effects of the Norwegian early retirement program AFP and emphasize effects caused by relocations of some individuals from disability pension and unemployment to AFP. Theoretical considerations predict that AFP unambiguously induces more early retirement. Analyzing Norwegian register data 1994–96 with parametric and non-parametric methods, we demonstrate that i) economic incentives influence the retirement decision, ii) there is a significant net induced retirement effect, iii) by a conservative judgment, at least 50% of the AFP retirees would have stayed in the labor force without the scheme.All correspondence to Espen Bratberg. We are indebted to the referees for detailed remarks, which significantly improved the paper. Financial support from the Norwegian Research Council and the Ministry of Health and Social Affairs is greatly appreciated. We are grateful for valuable comments from Erik Hernæs and Astrid Grasdal, seminar participants at the Norwegian School of Management in Oslo, the Institute for International Economic Studies in Stockholm, and the University of Linz, the 2000 Conference of the European Society for Population Economics in Bonn, and the German-Norwegian Seminar on Social Insurance in Berlin, 2000. Bratberg would also like to thank the Humboldt University for its hospitality during a stay in the winter of 2003. Responsible editor: Christoph M. Schmidt.     

Individual mobility,population growth and labor force participation

Trends in labor force participation rates and the age of retirement are shown to be important determinants of upward mobility. Reductions in age specific participation rates increase the speed of movement through the employment hierarchy. In conjunction with economic development, the falling labor force participation of older men acts to offset the adverse effects of slowing population growth on promotional prospects. These conclusions are reached by extending a model of employment status developed by Keyfitz to limit employment competition to only those actually in the labor force.     

Age structure,education, and the transmission of technical change

The significance of deviations from exponential population growth to economic development requires the construction of growth models that explicitly recognize demographic forces as a potential source of nonstationarities. This paper uses an overlapping generations approach to analyze the impact of population aging on technological innovations in the production process. Specifically, it is assumed that a newly invented technology can be used only if the production unit engages human labor that has been trained for this task (labor-embodied technical change). In a model of overlapping generations 1-sector optimal growth, there are 3 basic components: population, education and labor, and production and investment. An individual who has been in school continuously from the time of birth embodies, according to this model, the most up-to-date form of human capital. When the population growth rate is high, technological innovations are achieved largely through the constant influx of recently educated young people into the labor force. However, when population declines lead to a slowing down of this influx, increased adult education is necessary to stimulate the continued introduction of innovations into the productive process. The form of the optimality conditions, the comparative statistics properties, and the form of the nonstationary optimal economic growth path in this model are similar to those in the Van Imhoff model of homogeneous human capital.     

Targeting Spatial Clusters of Elderly Consumers in the U.S.A

For business demographers, a noteworthy aspect of national population aging is the course of its onset at local scales, such as neighborhoods and individual city blocks. Across the U. S., particular neighborhoods are evolving through aging in place into de facto retirement communities, populated by elderly residents who continue to live independently. An increasingly common manifestation of this development is the so-called naturally occurring retirement community (NORC)—a neighborhood where adults have stayed on and grown old while younger people have drifted away. NORCs materialize gradually over time where initial cohorts settle in close proximity and age in place, while subsequent younger cohorts move away. These settings offer novel opportunities for prolonging independent living in old age. They constitute distinctive readymade consumer markets as well, especially for businesses that rely on word of mouth. We present a general approach to spotting NORCs. We then consider such enclaves as potential target markets, both for community planners aiming to centralize service delivery to the elderly and for businesses offering types of services that can be bundled profitably for these residential concentrations of elderly.     

Social security reforms and early retirement

Many reform proposals of the social security systems in various OECD economies suggest to scale down the non-actuarial parts of the pension systems. These reforms have a flavor of increased efficiency at the costs of welfare losses for low-income individuals. Assessing the economic effects, we investigate five different reform proposals by means of a numerical overlapping generations model for the Norwegian economy. The model features an endogenous retirement age and heterogeneous individuals within generations. It turns out that the various reforms, which scale down the public non-actuarial pension system, lead to increases in the retirement age and steady-state welfare gains for all income classes. Received: 7 December 2000/Accepted: 29 January 2002 All correspondence to ?ystein Th?gersen. Financial support from the Research Council of Norway (The Economic Research Program on Taxation) is gratefully acknowledged. We are indebted to Lans Bovenberg, John Ermisch, Erling Steigum and two referees for valuable comments and useful discussion. Responsible editor: John F. Ermisch.     

人口年龄结构变动下的最优退休年龄动态模型构建与应用——以陕西省为例

文章主要以社会福利最大化为基本前提,假定社会福利最大化条件下的退休年龄为最优平均退休年龄,通过建立人口年龄结构变动下的最优退休年龄动态模型,以陕西省人口数据和养老保险相关数据为基础,测算了社会福利最大化条件下的陕西省最优平均退休年龄。得出结论:满足社会福利最大化时,陕西省最优平均退休年龄将会从2010年的58.4岁,逐步提高到2020年的59.6岁,进而提高到2030年的61.3岁。