“Replacement Migration” from the Perspective of Equilibrium Stationary Populations

An equilibrium stationary population results whenever a population is projected assuming (constant) below-replacement fertility and annual flow of net migrants whose age-sex composition is also fixed. This framework is useful in interpreting the results in the U.N.'s report on Replacement Migration. It is especially helpful in seeing why the annual volume of immigration must accelerate if the policy goal is to maintain today's relatively youthful age structures. Replacement Migration is largely demographic in nature and ignores a number of potential connections to economics and other social sciences. Had those connections been strengthened, readers might have been more convinced that population aging and population decline are important problems that require immigration as a solution.     

Demographers’ Involvement in Twentieth-Century Population Policy: Continuity or Discontinuity?

The second half of the twentieth century witnessed the development of a crusading spirit and massive technical aid aimed at reducing fertility levels and rates of population growth in developing countries, and also the involvement of demographers in these events. The demographers at Princeton University’s Office of Population Research, Frank Notestein and his colleagues, have been singled out by recent authors as playing a unique role in bringing about these changes, and they have been criticized for encouraging demographers to become involved, so eroding their scientific objectivity. This paper examines the development of relevant population thought and theory in the English-language literature over the first half of the twentieth century. It concludes that in the circumstances of the second half of the twentieth century, it was inevitable that developed countries and their demographers would become involved in controlling fertility levels in developing countries. The OPR story should be seen largely in terms of how the world’s leading demographic center and its demographic transition theory were swept along by global changes. As those developments started, attitudes to population change in densely settled Asia became Malthusian, even as population growth accompanied by mortality decline in Asia demonstrated that, at least in the short term, the positive checks were disappearing.     

The United Nations on World Population in 2300

The Population Division of the United Nations biennially issues detailed population estimates and projections covering the period 1950–2050. The most recent revision of these estimates and projections, the 2002 assessment, was released in February 2003. At irregular intervals, the Population Division also publishes long‐range projections. The most recent of these, covering the period up to 2150, was issued in 2000, based on the 1998 assessment. On 9 December 2003, the Population Division released the preliminary report on a new set of long‐range projections, dovetailing with the 2002 assessment, that extend over a much longer time span: up to 2300 ( http://www.un.org/esa/population/publications/longrange2/longrange2.htm ). Unlike previous long‐range projections, which, apart from China and In‐dia, were prepared for large regional groupings only, the new projections are elaborated separately for 192 countries. Given the enormous uncertainties of the character of demographic trends over such an extended period, the information content of these projections is somewhat elusive. However, they are expected to be used to provide the demographic input for long‐range models of global climate change. Long‐range population projections also serve to demonstrate the unsustainability of certain seemingly plausible assumptions as to the future course of particular demographic parameters. In the present case, for example, the high‐fertility projection, reflecting a sustained total fertility rate at the relatively modest level of 2.35, by 2300 would yield a population of some 32 billion in the countries now classified as less developed. Or, in a yet more extreme exercise 0/reductio ad absurdum, maintaining constant fertility at present rates would result in a population size of some 120 trillion in the countries now classified as least developed. Apart from the “high fertility” and “constant fertility” models just cited, the projections are calculated for three additional instructive variants: “low fertility,”“medium fertility,” and “zero growth.” Underlying each of the five variants is a single assumption on mortality change: expectation of life at birth creeping up, country‐by‐country, to a 2300 level ranging between 88 and 106 years. International migration is set at zero throughout the period 2050‐2300 in each variant. Thus the projections are unabashedly stylized and surprise‐free, providing a simple demonstration of the consequences, in terms of population size and age structure, of clearly stated assumptions on the future course of demographic variables. Reproduced below is the Executive Summary of the preliminary report on the UN long‐range projections presented to a UN technical working group on long‐range projections at its December 2003 meeting in New York and slightly revised afterward. A full final report on this topic by the Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat will be published later in 2004.     

The UN Population Division on Replacement Migration

The most salient demographic trend pictured by the influential set of population projections prepared by the Population Division of the United Nations (a unit in the UN's Department of Economic and Social Affairs) is the continuing substantial increase—albeit at a declining rate—of the global population during the coming decades. According to the “medium” variant of the most recent (1998) revision of these projections, between 2000 and 2050 the expected net addition to the size of the world population will be some 2.85 billion, a figure larger than that of the total world population as recently as the mid‐1950s. All of this increase will occur in the countries currently classified as less developed; in fact, as a result of their anticipated persistent below‐replacement levels of fertility, the more developed regions as a whole would experience declining population size beginning about 2020, and would register a net population loss of some 33 million between 2000 and 2050. A report prepared by the UN Population Division and released on 21 March 2000 addresses some of the implications of the changes in population size and age structure that low‐fertility countries will be likely to experience. The 143‐page report, issued under the eyecatching title Replacement Migration: Is It a Solution to Declining and Ageing Populations?, highlights the expected magnitude of these changes by the imaginative device of answering three hypothetical questions. The answer to each of these questions is predicated on the assumption that some specified demographic feature of various country or regional populations would be maintained at the highest level that feature would exhibit, in the absence of international migration, in the United Nations' medium population projections (as revised in 1998) during the period 1995–2050. The selected demographic features are total population size, the size of the working‐age population (15–64 years), and the so‐called potential support ratio: the ratio of the working‐age population to the old‐age population (65 years and older). The illustrative device chosen for accomplishing the specified feats of preserving the selected demographic parameters (i.e., keeping them unchanged up to 2050 once their highest value is attained) is international migration. Hence the term “replacement migration.” Given the low levels of fertility and mortality now prevailing in the more developed world (and specifically in the eight countries and the two overlapping regions for which the numerical answers to the above questions are presented in the report), and given the expected future evolution of fertility and mortality incorporated in the UN population projections, the results are predictably startling. The magnitudes of the requisite compensatory migration streams tend to be huge relative both to current net inmigration flows and to the size of the receiving populations; least so in the case of the migration needed to maintain total population size and most so in the case of migration needed to counterbalance population aging by maintaining the support ratio. Reflecting its relatively high fertility and its past and current record of receiving a large influx of international migrants, the United States is a partial exception to this rule. But even for the US to maintain the support ratio at its highest—year 1995—level of 5.21 would require increasing net inmigration more than tenfold. The country, the report states, would have to receive 593 million immigrants between 1995 and 2050, or a yearly average of 10.8 million. The extreme case is the Republic of Korea, where the exercise calls for maintaining a support ratio of 12.6. To satisfy this requirement, Korea, with a current population of some 47 million, would need 5.1 billion immigrants between 1995 and 2050, or an average of 94 million immigrants per year. (In the calculations, the age and sex distribution of migrants is assumed to be the same as that observed in the past in the main immigration countries. The fertility and mortality of immigrants are assumed to be identical with those of the receiving population.) The “Executive Summary” of the report is reproduced below, with the permission of the United Nations. Chapters of the full report set out the issues that prompted the exercise; provide a selective review of the literature; explain the methodology and the assumptions underlying the calculations; and present the detailed results for the eight countries and two regions selected for illustrative purposes. A brief discussion of the implications of the findings concludes the report. As is evident even from the figures just cited, immigration is shown to be at best a modest potential palliative to whatever problems declining population size and population aging are likely to pose to low‐fertility countries. The calculations, however, vividly illustrate that demographic changes will profoundly affect society and the economy, and will require adjustments that remain inadequately appreciated and assessed. The criteria specified in the UN calculations—maintenance of particular demographic parameters at a peak value—of course do not necessarily have special normative significance. Past demographic changes, with respect notably to the age distribution as well as population size, have been substantial, yet they have been successfully accommodated under circumstances of growing prosperity in many countries. But the past may be an imperfect guide in confronting the evolving dynamics of low‐fertility populations. As the report convincingly states, the new demographic challenges will require comprehensive reassessments of many established economic and social policies and programs.     

Population,projections, and policy: A cautionary perspective

Population projections depend on censuses, vital statistics and sample surveys, all of which have deficiencies that are most marked in the less developed countries (LDCs). Long-range projections by international agencies have recently undergone major revisions, while forecasts of the U.S. population have changed drastically over the past four years. The United Nations typically prepares “high,” “medium” and “low” projections. Even the high projection contains optimistic assumptions about fertility decline, while assumptions of constant or increasing fertility receive no serious attention. The paper suggests that high and constant fertility projections should receive more attention from policy makers, with medium estimates treated more as targets achievable only through considerable programmatic effort. At the same time, economic and social plans should be laid for dealing with the population sizes implied by the “high” variants.     

日本失去的二十年——基于中日人口红利比较的视角

"人口红利"是人口因素与经济增长关系研究的深入和发展。亚洲地区经济高速增长和工业化国家人口老龄化条件下经济增长,分别对应第一次"人口红利"和第二次"人口红利"。中国与日本相比,无论是经济增长模式还是人口转变模式,都有着极为相似之处,本文旨在通过对比分析中日两国人口发展与经济发展之间的变化,借鉴日本人口红利期的经验和教训,为中国充分实现第一次人口红利、创造第二次人口红利提供参考。     

Can migration avert population decline and ageing in East and Southeast Asia?

Fertility is currently below replacement level in China, Hong Kong, Japan, Macao, the Republic of Korea, Singapore, Taiwan and Thailand. These low levels are expected to lead to declines in the total population and the number of persons of labour force age. In a report that garnered much attention among policy-makers and the news media, the United Nations Population Division developed the concept of replacement migration. This was defined as the number of international migrants that would be required in order to prevent the declines in the total population; the number of persons of working age; or the potential support ratio (persons aged 15–64 per person aged 65 and over). This paper reviews the hypothetical replacement migration projections for Japan and the Republic of Korea in the United Nations report and examines similar scenarios for China, Singapore, Taiwan and Thailand, with a brief overview of possible policy implications.     

中国人口转变、人口红利与经济增长的实证

我国人口年龄结构的变动使得劳动负担逐渐下降,这对于储蓄水平的上升和劳动力投入效率的提高具有显著的促进作用;我国劳动负担比与经济增长呈现出明显的负相关,劳动负担比每下降1个百分点,经济增长将提高1.06个百分点,在过去的30年里劳动负担降低累计带来的经济增长占总增长的27.23%。通过计量检验证明人口年龄结构变动所产生的促进经济增长的人口红利是存在的。由此我们推断,由于未来的人口年龄结构变动趋向人口老龄化,劳动负担逐步上升,这将会对未来的经济增长造成制约。利用未来10～20年时间较轻的劳动负担的机遇期,我们应当建立良好的教育、人力资本投资、社会保障等方面的制度以及制定积极的人口政策,调整当前生育政策、适时执行宏观经济政策(劳动就业政策)来应对已发生的、正在进行的人口变动,使我国的经济继续保持强有力的增长态势。     

Population Aging and the Rising Cost of Public Pensions

Rapid population aging is raising concerns about the sustainability of public pension systems in high‐income countries. The first part of this study identifies the four factors that determine trends in public pension expenditures: population aging, pension benefit levels, the mean age at retirement, and the labor force participation rate. The second part presents projections to 2050 of the impact of demographic trends on public pension expenditures in the absence of changes in pension benefits, labor force participation, and age at retirement. These projections demonstrate that current trends are unsustainable, because without reforms population aging will produce an unprecedented and harmful accumulation of public debt. A number of projection variants assess the potential impact of policy options aimed at improving the sustainability of public pension systems. Although the conventional responses are considered, particular attention is given to the demographic options of encouraging higher fertility and permitting more immigration. This analysis is illustrated with data from the seven largest OECD countries.     

中国的人口转变完成了吗?

本文依据 1 998年我国人口一些重要指标所达到的水平 ,并通过与发达国家同类指标达到相同或相近水平时间的比较 ,判定我国人口转变过程在 2 0世纪末已经结束 ,人口增长从低增长走向零增长和人口结构性变动成为调节人口增长势态的主要因素这两个后人口转变时期人口变动的基本特征在我国已经开始显现出来     

俄罗斯的人口老龄化

随着社会经济的发展和科技进步,人口老龄化已经成为现代社会的必然趋势,是世界各国普遍面临的重大社会问题。俄罗斯人口转变过程开始的时间较晚,但人口老龄化速度较快,地区差异大,而且城市和农村之间存在差别,老龄化形势严峻。制定合理的、符合本国国情的社会政策能够缓解人口老龄化问题。     

A Multidimensional Approach in International Comparative Policy Analysis Based on Demographic Projections

The present study adopts a multidimensional approach to classifying countries in international comparative policy analyses. The article builds a data-based typology founded on future demographic projections of the United Nations. Latent class analysis is used to identify various demographic profiles of countries based on fertility rates, net migration rates, and dependency ratios. There is great value in identifying future changes in population composition, as it enables governments to set policy agenda, prioritize needs, and prepare better for what lies ahead. The paper demonstrates the value of such typology to social services, by analyzing the demographic profiles and estimating their implications for future challenges in educational provision. The contributions of the paper to international comparative policy analysis are discussed.     

World population beyond six billion

This world report reviews population growth pre-1900, population change during 1900-50 and 1950-2000, causes and effects of population change and projections to 2050. World population grew from 2 billion in 1900 to almost 6 billion in 2000. Population showed more rapid growth in the 17th and 18th centuries. Better hygiene and public sanitation in the 19th century led to expanded life expectancies and quicker growth, primarily in developed countries. Demographic transition in the 19th and 20th centuries was the result of shifts from high to low mortality and fertility. The pace of change varies with culture, level of economic development, and other factors. Not all countries follow the same path of change. The reproductive revolution in the mid-20th century and modern contraception led to greater individual control of fertility and the potential for rapid fertility decline. Political and cultural barriers that limit access affect the pace of decline. Population change is also affected by migration. Migration has the largest effect on the distribution of population. Bongaarts explains differences in fertility by the proportion in unions, contraceptive prevalence, infertility, and abortion. Educational status has a strong impact on adoption of family planning. Poverty is associated with multiple risks. In 2050, population could reach 10.7 billion or remain low at 7.3 billion.     

亚洲人口老龄化的发展、挑战以及应对策略

人口老龄化已经成为亚洲国家必须面对的一个十分紧迫的问题,与西方相比,亚洲国家的老龄化问题更加复杂,这种复杂性不仅在于过快的老龄化速度,更重要的是亚洲在经济、制度发展方面远未成熟,同时老龄化又存在城乡失衡、性别比例失衡等现象。老龄化对亚洲未来经济发展带来了挑战,亚洲内部的产品内分工链、区域生产网络等维持亚洲竞争能力的区域合作模式很大程度上是建立在人口红利基础上的,老龄化的发展将使得亚洲传统发展模式无法持续。面对这些挑战,亚洲国家必须迅速采取有效措施积极应对。     

计划生育政策的人口效应

文章试图估计计划生育政策使我国少生了多少人。利用1980~2008年世界140多个国家的数据来模拟在没有计划生育政策影响下经济社会变量与人口变量的相关关系,并据此对中国无计划生育条件下的总和生育率进行测算。将测算出来的无计划生育条件下的总和生育率和中国实际总和生育率分别代入模型进行人口模拟,比较无计划生育条件下和现实条件下人口增长的不同过程和结果。研究表明:无计划生育条件下,我国2008年生育率水平的预测值大概在2.5左右。1972~2008年间,排除经济社会发展的影响,单纯由于计划生育的作用,中国少生了4.58亿人。     

U.S. Family Household Momentum and Dynamics: An Extension and Application of the ProFamy Method

The classic headship-rate method for demographic projections of households is not linked to demographic rates, projects a few household types without size, and does not deal with household members other than heads. By comparison, the ProFamy method uses demographic rates as input and projects more detailed household types, sizes, and living arrangements for all members of the population. Tests of projections from 1990 to 2000 using ProFamy and based on observed U.S. demographic rates before 1991 show that discrepancies between our projections and census observations in 2000 are reasonably small, validating the new method. Using data from national surveys and vital statistics, census microfiles, and the ProFamy method, we prepare projections of U.S. households from 2000 to 2050. Medium projections as well as projections based on smaller and larger family scenarios with corresponding combinations of assumptions of marriage/union formation and dissolution, fertility, mortality, and international migration are performed to analyze future trends of U.S. households and their possible higher and lower bounds, as well as enormous racial differentials. To our knowledge, the household projections reported in this article are the first to have found empirical evidence of family household momentum and to have provided informative low and high bounds of various indices of projected future households and living arrangements distributions based on possible changes in demographic parameters.     

Aging in Japan: population policy implications

This article was prepared for the International Conference on Aging in the East and West in 1995. The focus is on trends in aging in Japan and demographic determinants and consequences. Findings are presented from a 1990 study conducted by the Institute of Population Problems on acceptance of alternative population policies aimed to slow population aging in Japan. Japan is the seventh most populous country in the world, and the current growth rate is around 0.3%. Declines in fertility and mortality have contributed to the low growth rate. Population aging accelerated over the decades. The present share of aged population is 14.1%. The aged population is expected to continue to increase from 14.9 million in 1990 to 32.7 million in 2020 (25.8% in 2025). Decreases in the aged population are not expected until after the mid-2040s. The proportion of very old (ages 75 years and older) will dramatically increase to 14.5% in 2025. The primary demographic determinant of population aging and fertility decline is identified as the higher proportion of never-married and the higher age at marriage. One of the consequences of population aging is the increase in the age dependency ratios and the aged-child ratios. The proportion of intergenerationally extended households declined over time, but the pace of decline has slowed recently. The proportion of aged in one person or couple only households has risen but not to the same extent as the West. The majority of older old still live with a married child. Logistic analysis of 1985 survey data reveal that the custom of the elderly living with the eldest child remains. The 1985 survey also revealed much indecision about a pronatalist policy or a fertility policy. Logistic analysis of 1990 public opinion survey data shows acceptance of immigration as a policy alternative to slowing population aging. Acceptance varied by socioeconomic, demographic, and regional factors. A pronatalist policy received stronger acceptance. However, reference is made to Kojima's literature review, which suggests that indirect policies on fertility and a comprehensive family policy would be more effective in raising fertility than a population policy.     

Understanding population projections

This is a general introduction to how population projections are made and used for the consumers of this information. Population projections are computations of what future trends in fertility, mortality and migration of a population might be given set assumptions. They are not actual forecasts. Projections are used by planners in government and business for a clearer understanding of social changes. How to prepare projections, obtain base data, select starting and future levels of rates, variant series, and the mathematics involved are discussed. Assumptions must be carefully checked and chosen, since reliability of the projections depends on assumptions. There are 3 rules of thumb for reliability: 1) the shorter the projection period, the more reliable the projection; 2) the larger the geographic area being projected the more reliable the projection; 3) the lower the current fertility and the higher the current life expectancy, the lower the projection's margin of error. Major sources of data and projections on world, regional, national, subnational, and local areas and difficulties with data for developing countries are discussed. Available microcomputer programs for IBM PC compatible machines are listed and described briefly.     

The Media Marketplace for Garbled Demography

Differences in cultural norms and incentives provide a powerful marketplace for garbled demography in the mass media. Journalists are attracted to expectation of dramatic shifts in politically and socially controversial domains that can result from long‐term population projections. Demographers routinely caution against interpreting such projections as forecasts, and emphasize the complexities and uncertainties of demographic analyses. Yet such caveats are often lost in the sequence of translations from demographic study, to press release, to journalistic treatment. In addition, advocacy groups often interpret such stories to serve their own interests, while headlines and article titles designed for general readerships are another source of miscommunication about demographic studies. Two recent cases offer object lessons of how careful demographic analyses addressing politically controversial trends can suffer from such confusions: media coverage of the 1997 National Research Council report entitled The New Americans, and the 2000 report by the United Nations Population Division entitled Replacement Migration: Is It a Solution to Declining and Ageing Populations? The essay suggests procedural changes that might moderate the level of garbled reporting and commentary that commonly characterize coverage of such studies in the mass media.