Populations with constant immigration

"We consider a Leslie-type model of a one-sex (female) population of natives with constant immigration. The fertility and mortality schedule of the natives may be below or above replacement level. Immigrants retain their fertility and mortality, their children adopt the fertility and mortality of the natives. It is shown how this model may be written in a homogeneous form (without additive term) with a Leslie-type matrix. Reproductive values of individuals in each age group are discussed in terms of a left eigenvector of this matrix. The homogeneous form of our projection model permits the transformation into a Markov chain with transient and recurrent states. The Markov chain is the basis for the definition of genealogies, which incorporate immigration. It is shown that genealogies describe the life histories of individuals in a population with immigration. We calculate absorption times of the Markov chain and relate them to genealogies. This extends the theory originally designed for closed populations to populations with immigration." (SUMMARY IN FRE)     

Populations with constant immigration

We consider a Leslie‐type model of a one‐sex (female) population of natives with constant immigration. The fertility and mortality schedule of the natives may be below or above replacement level. Immigrants retain their fertility and mortality, their children adopt the fertility and mortality of the natives. It is shown how this model may be written in a homogeneous form (without additive term) with a Leslie‐type matrix. Reproductive values of individuals in each age group are discussed in terms of a left eigenvector of this matrix. The homogeneous form of our projection model permits the transformation into a Markov chain with transient and recurrent states. The Markov chain is the basis for the definition of genealogies, which incorporate immigration. It is shown that genealogies describe the life histories of individuals in a population with immigration. We calculate absorption times of the Markov chain and relate them to genealogies. This extends the theory originally designed for closed populations to populations with immigratioa     

The Level and Age Pattern of Mortality in Bandafassi (Eastern Senegal): Results From a Small-Scale and Intensive Multi-Round Survey

The data collected in the Bandafassi demographic study in Eastern Senegal, a small-scale intensive and experimental follow-up survey of a population of about 7,000 in 1983, were analysed to derive an estimated life table. The use of multi-round surveys, combined with anthropological methods to estimate ages and collect genealogies, has resulted in unusually reliable data. Taking into account the uncertainty of the estimates due to the small size of the population, mortality was high, with life-expectancy at birth close to 31 years; a pattern of infant and child mortality close to that observed in other rural areas of Senegal, with a very high level or mortality between ages six months and three years; a seasonal pattern in child mortality with two high-risk periods, the rainy season and the end of the dry season; an adult mortality pattern similar to that described in model life tables for developed countries; no significant difference by sex or ethnic group. The Bandafassi population study and a few similar studies suggest that one possible way to improve demographic estimates in countries where vital registration systems are defective would be to set up a sample of population laboratories where intensive methods of data collection would continue for extended periods.     

Family and country: accounting for fractured connections under colonisation in Victoria,Australia

The Koori Health Research Database (KHRD) began in 2000, as a partnership between the Bunjilaka Aboriginal Cultural Centre at Museum Victoria and the Onemda Koori Health Unit at the University of Melbourne. Its purpose is to reconstitute the Aboriginal population of Victoria under colonisation, using family histories, genealogies, civil registrations, and other historical records of the colonising state. The KHRD is unique internationally as a cradle-to-grave dataset documenting from the mid-nineteenth century the demography and health of an indigenous people under colonisation. This paper discusses the historical context of the database, our changing understanding based on recent enhancement of the data and new research by other scholars, and the light it sheds on the official strategies of alienation from country and family and their demographic consequences. It demonstrates the paradox, that while concentration of the remnant Aboriginal people into government reserves was destructive to their health and wellbeing, it enabled those Victorian Aboriginal people to preserve the knowledge of their lineages, languages and culture.     

Public expenditures,population aging and economic dependency in Canada, 1921–2021

The slowing population growth and consequent aging of the population in Canada and elsewhere have raised questions of the ability of such populations to provide support to their non-working or dependent, particularly their aged, members. Previous discussions have often been focussed on demographic measures of dependency, but more recent research has shown that, in North American society, the per capita costs of providing public programmes to an elderly member are between two and three times higher than those to a younger member of society. However, these measures have made no attempt to take into account changing labour market conditions. This paper develops measures of dependency to incorporate these latter effects. Calculations with Canadian data (1921–2021) show that demographic and economic dependency in Canada are currently at historically low levels. The numerical results also suggest that the effects of the general increases in labour force participation rates, that have characterized the past two decades, have more than offset the effects of the general increases in unemployment rates, and that future increases in participation rates and, perhaps, decreases in unemployment rates could provide a significant alleviation of the impacts of population aging on government expenditures in the years ahead.     

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.     

Old age and the demographic transition

Summary This paper examines the impact of the demographic transition upon the potential supply of, and demand for, family support for the aged in Australia. Using census and survey information on population cohorts entering old age, comparisons are drawn concerning their surviving issue, household composition and family membership. Long-term changes in fertility are shown to have had only a small impact upon the supply of potential carers among relatives and, although the demographic transition has led to a more universal inclusion of old people in family networks, there have not been major changes through time in the proportions living in extended family households. Short-term changes, however, such as low fertility during the 1930s, have caused disordered cohort flow, with the result that current generations of the elderly are members of deprived cohorts in terms of their access to family support.     

Infant and Child Mortality Among the Qing Nobility: Implications for Two Types of Positive Check

Demographers, as early as Malthus, have assumed that in traditional China the positive check, mortality, was largely beyond human control. This paper re-examines the role of the positive check in late imperial China through an analysis of an historical source of unprecedented demographic detail and accuracy: the genealogy of the Qing (1644–1911) imperial lineage. Basing ourselves on our calculations on the infant, child, and young adult mortality of 33,000 lineage members born in Beijing between 1700 and 1840, we conclude that during the late eighteenth century, many lineage couples regularly used infanticide to control the number and sex of their infants. At the same time, they also took advantage of innovations in paediatric care to protect the children they decided to keep. Although these results derive from an elite population, they, nevertheless, call into question our understanding of the operation of the positive check in late imperial China's demographic system, suggesting a much larger potential role for individual agency than was previously thought.     

A multi-dimensional model for projecting family households--with an illustrative numerical application

"This paper develops a multi-dimensional model for projecting households and population. The model is constructed to ensure consistency between the demographic events occurring to males and females as well as to parents and children. The model permits projection of characteristics of households, their members, and population structure, using data that are usually available from conventional sources. Unlike the traditional headship-rate method, our model can closely link the projected households with demographic rates. The model includes both nuclear and three-generation households, so that it can be used for countries where nuclear households are dominant and for countries where nuclear and three-generation households are both important. The illustrative application to China, although brief, provides some policy-relevant information about future trends of Chinese household size, structure, and the age and sex distribution of the population, with a focus on the elderly."     

Population estimates from longitudinal records in otherwise data-deficient settings

Existing methods for estimating population parameters in settings of data deficiency do not provide techniques for analysis of commonly available longitudinal data. In setting where complete population data is unavailable, longitudinal data recorded for only a subset of the total population are often available (e.g., event registers, genealogies). In this article we present and evaluate models which derive population parameters for the population subgroup underlying such longitudinal data. Using the distribution of individual times until first recorded event within a measurement interval, population parameters are estimated which provide basic denominator data for analyzing event occurrence. The models which we derive are especially suited to records which may include migration and population growth trends. The use of the models is demonstrated and evaluated through an application to genealogical records for a nineteenth-century population. Possible extensions of these models and their major limitations are also discussed.     

Estimating the Expectation of Life at Old Ages: Comments on the Article by Mitra

Family reconstitution studies assess demographic behaviour for that section of the population that remains in the parish of their birth. Although there has been considerable discussion of whether or not these non-migrants are representative of the population as a whole, the distorting effects of migration censoring have not been adequately considered. This paper shows that even when the demographic behaviour of non-migrants is identical to that of the general population, migration-censoring will significantly bias family reconstitution results. In particular, existing family reconstitution studies underestimate both age at marriage and life expectancy. The paper assesses the potential magnitude of bias introduced by migration, and suggests several new techniques for correcting the errors.     

Population Association of China (PAC)

In the past 3 years, the Population Association of China, an independent, academic, and nongovernment organization established in February 1981, organized demographers throughout China to tackle the population problems that emerged in the course of the nation's socioeconomic development. Thus, by organizing and promoting exchanges, the Association did help to push forward the vigorous development of population science. Now PAC has over 500 individuals and organized units as members. It has 90 council members and 19 permanent council members. Its annual tasks and research priorities are discussed and decided by the permanent council, and then implemented in various departments and localities by its council or association members. The Population Association has organized various academic activities among demographers to study the characteristics of different periods. 1983 is an important year for the reform of social and economic systems in China. The new situation and problems brought about by the reform are bound to affect the control of population growth. Consequently, the Association decided to emphasize the control of population growth in rural areas. At the same time, the Association advocated a style of study which required people to delve into the realities of life and to investigate and study these realities thoroughly. For this purpose, 3 discussions were either financed or authorized by the Association in a single year. At the symposiums, demographers and field workers, proceeding from their country's reality and by applying the Marxist point of view, tried to find effective solutions to the demographic problems. As a result, they produced a number of valuable academic reports. In the last few years, PAC played an important role in international academic activities and exchanges. Reviewing the past and looking ahead to the future, PAC will further unite China's demographers to make new contributions to the development of the country's population science and the control of her population growth.     

Minimal Household Units: A New Approach to the Analysis of Household Formation

In this paper a new method for the analysis of household formation and the composition of households is described. The components, or building blocks, which combine to form households are identified and these have been called ‘minimal household units’. The focus of the analysis is on whether a minimal household unit sets up as a separate household or, if not, with whom it is shared. An economic theory of household formation is outlined, and a probit model is used to guide the estimation of the effects of economic and demographic characteristics of the minimal household unit on the probability of being a separate household, economic factors, such as the unit's income, and other social and demographic characteristics of the unit's members are shown to have a significant influence on the probability of its being a separate household.     

Inverse Projection and Back Projection: A Critical Appraisal,and Comparative Results for England, 1539 to 1871

Inverse projection and back projection are two methods for exploiting long historical series of births and deaths to produce estimates of population size and age structure, net migration, and vital rates. While inverse projection requires extraneous information on population size at scattered dates, back projection does not. In this paper I argue that back projection attempts an impossible task, and can only arbitrarily select one demographic past from among an infinite set of equally plausible and acceptable ones, which are also consistent with the input data. Inverse projection, on the other hand, is more modest in its goal, but is robust and straightforward. In an important and outstanding book, Wrigley and Schofield use back projection to reconstruct English demographic history from 1539 to 1871. In this paper, inverse projection is used to replicate their reconstruction under assumptions that are in important respects weaker, although these estimates are contingent on independent population size estimates for 1541 and 1696. The results buttress Wrigley and Schofield's reconstruction. However, it is argued that their data and reconstruction cannot offer independent evidence for the general levels of population before the mid-eighteenth century; rather, they help us to interpolate among benchmarks for which we have extraneous evidence, and contingent on these benchmarks, fill in the rich details of the demographic past.     

Helpless Dependents or Active Independents: A Cluster Analysis of Elders in China

The current study aimed to gain a better understanding of Chinese seniors’ demographic information as well as their attitudes toward old-age support as an indicator for their subjective well-being related to their retirement preparation. Particularly, the variation of demographic and attitudinal characteristics within the population was examined. The data was based on a sample of the Chinese senior population, aged 60 and over in 2006 from 20 provinces and metropolitan areas in China. A two-step cluster analysis was used in the current study and the auto-clustering algorithm indicated a two-cluster solution. Both demographic information and attitudinal responses were used for the clusters. The results showed that Chinese seniors’ attitudinal and behavioral traits were relevant to the classification with regard to their retirement preparedness. The current study demonstrated that Chinese seniors were a heterogeneous group that could be divided into two basic, distinct segments, namely, helpless dependents and active independents. Each different group of seniors may raise different key issues in meeting their needs for retirement management.     

European Demographic Forecasts Have Not Become More Accurate Over the Past 25 Years

Nowadays, demographers, population statisticians, and population forecasters have richer data, more refined theories of demographic behavior, and more sophisticated methods of analysis than they had two or three decades ago. This scientific progress should have made it easier to predict demographic behavior. But analyses of the errors in older forecasts show that demographic forecasts published by statistical agencies in 14 European countries have not become more accurate over the past 25 years. The findings demonstrate that scientific progress in population studies during the previous two to three decades has not kept up with the trend toward less predictable demographic behavior of populations in European countries. There is no reason to be more optimistic about US Census Bureau forecasts. Population forecasts are intrinsically uncertain, hence should be couched in probabilistic terms.     

Short-term, population-based forecasting in the public sector

There has recently been a tremendous expansion of the range of problems to which the demographic perspective is applied. Development of a new population-based method to solve the problem of forecasting income assistance caseloads for the state of Washington represents yet another effort in which the demographic perspective helps solve two major public-policy problems: (1) providing accurate and useful forecasts of caseloads, and (2) creating a dynamic model with which to analyze alternative policy proposals. When forecasting or examining the caseload history, it is also common to look at these caseload levels as a time-series. A caseload grows and shrinks as time passes because new members enter the caseload from a population of potential clients while other members exit the caseload. Population-based forecasting, as reported here, is really quite a novel approach to forecasting public assistance caseloads. In most situations, simple extrapolations of past trends or econometric time-series models are used. Characteristics associated with entries and exits can be used to develop dynamic models of current and future caseload changes. For budgeting purposes, these models can be readily translated into average annual caseload levels and can be directly used to examine policy alternatives and programmatic options. Entry and exit rates and volumes can be related to historical, current, and anticipated changes in economic, social, and programmatic conditions to develop models of caseload behavior, and ultimately, forecasts of caseload levels that are used for budget development.     

延续香火的理想与普遍绝嗣的现实——基于家谱的人口数据

延续香火、专宗接代②是传统社会人们的普遍愿望和理想,然而,由于传统时代人口的高死亡率和极短的预期寿命,延续香火的理想对于大多数人来说难以实现,绝嗣现象普遍存在。本文依据家谱的人口信息,通过构建虚拟的家族支脉,考察了清代两百余年间家族支脉的繁衍状况。结果显示,仅有13.61%的人在经历了两百余年的生存竞争后,能够拥有自己的后代,而其他大多数都已绝嗣,传嗣的理想和现实之间存在巨大的落差。     

Geopolitical Aspects of Population in the Twenty‐First Century

Over the second half of the twentieth century rapid population growth in the less developed countries has redrawn the global demographic map. Many once‐poor countries have also experienced strong economic growth, which in combination with the demographic change has yielded marked shifts in the world's economic balance, with far‐reaching geopolitical implications. At the same time, low fertility in much of the developed world presages a future of population shrinkage, accompanied by pronounced population aging. In per capita terms, the economic advantages of the developed countries will likely persist for many years, but their actual and potential falls in population may accentuate their loss of relative economic power and eventually lead to marginalization of their international standing and influence. Preventing population shrinkage will be an urgent task for them, requiring either large‐scale immigration (likely to be ruled out) or raising the birth rate. Existing pro‐family policies have had at best modest effects on fertility levels. Two novel approaches are described that would plausibly have greater impact. One would counteract the disproportionate influence of older voters in the electorate by granting voting rights to all citizens, allowing custodial parents to vote on behalf of their children. The second would reform the public pension system to reestablish the link between the financial security of retired persons and the number of children they have raised to productive adulthood.     

Countries with Rapid Population Growth and Resource Constraints: Issues of Food,Agriculture, and Development

Recent long‐term demographic projections suggest a fast deceleration of global population growth and the eventual peaking of world population later in this century at about 9.2 billion, roughly 50 percent above the present level. Some low‐income and food‐insecure countries, however, have projected populations in 2050 that are multiples of present ones. In some of these countries agriculture must play a leading role in their development efforts because they have high economic dependence on that sector. For those among them that have scarce agricultural resources, a prima facie case can be made that the high population growth rates projected may not be compatible with the development potential offered by such resources. Their demographic projections may need to be revisited, taking into account such inadequate potential. The global demographic slowdown notwithstanding, the “population explosion”‐related issues pertaining to food and agriculture will not become irrelevant but will be become increasingly localized.