Analysing open birth interval distributions

Summary This paper began with the recognition that open birth interval distributions are analogous to age distributions. It then became clear that closed birth interval distributions are, somewhat more loosely, analogous to mortality schedules, and that the relationship between open and closed birth interval distributions could be explored by imitating the formal demography of mortality and age distribution. Pursuing this programme, we develop the formal demography of open and closed birth interval distributions and show that under certain assumptions open interval distributions may be used to estimate closed interval distributions, just as age distributions may be used to estimate mortality. An illustrative application to Indonesian data is given.     

Historical Demography: Achievements and Prospects

Historical demography as a separate discipline came into existence when family reconstruction was first developed for the analysis of a pre-transition population. This paper assesses the significant achievements made in this field of population studies since then. Attention is also paid to equally significant findings obtained from aggregative analysis based on back projection, and to a large body of research results for the period of the demographic transition. In the last part of the paper, new research directions are discussed. Data issues as well as methodological ones are raised. Special attention is given to newly emerging Asian historical demography where different source materials require different methods and techniques, which in turn are expected to broaden the scope of the so far disproportionality fertility-oriented field. Finally, discussions are extended to economic, cultural and institutional aspects of the subject, with a plea not to isolate demographic analysis from other branches of historical research.     

Historical demography: achievements and prospects

Historical demography as a separate discipline came into existence when family reconstruction was first developed for the analysis of a pre-transition population. This paper assesses the significant achievements made in this field of population studies since then. Attention is also paid to equally significant findings obtained from aggregative analysis based on back projection, and to a large body of research results for the period of the demographic transition. In the last part of the paper, new research directions are discussed. Data issues as well as methodological ones are raised. Special attention is given to newly emerging Asian historical demography where different source materials require different methods and techniques, which in turn are expected to broaden the scope of the so far disproportionality fertility-oriented field. Finally, discussions are extended to economic, cultural and institutional aspects of the subject, with a plea not to isolate demographic analysis from other branches of historical research.     

Demography as a Spatial Social Science

Scholars in many social science disciplines have taken note of the re-emerging interest in issues concerning social processes embedded within a spatial context. While some argue that this awakening is refreshing and new and, in fact, long overdue, I demonstrate that spatially focused demographic theories and research agendas clearly predate contemporary interest in these topics. I assert that recent methodological advancements have merely encouraged and brought refinement to the expanding body of spatially oriented population research—research strongly rooted in demographic tradition and practice. Indeed, I make the claim that, until roughly the mid-20th century, virtually all demography in the United States (and elsewhere, but not specifically examined here) was spatial demography. Then, shortly after mid-century, a paradigm shift occurred, and the scientific study of population quickly came to be dominated by attention to the individual as the agent of demographic action. Traditional spatial demography—macro-demography—gave way to micro-demography, and, I argue, most demographers simply abandoned the data and approach of spatial demography. In closing the paper I include a brief discussion of the recent awakening that has come to spatial demographers from developments in other disciplines, principally geography, regional science, and spatial econometrics.     

Spatial Demography: An Opportunity to Improve Policy Making at Diverse Decision Levels

The number of applications of spatial demography has been growing mostly since the 1990s. Ranging from simple visualization to sophisticated spatial analytical techniques, these applications bring a new layer of explanation to demographic phenomena. This paper reviews demographic studies that specifically addressed space with spatial statistical models, and that focused on fertility, mortality, migration, and population models. Additionally, it summarizes different spatial datasets and software freely available, as well as the challenges that exist for the development of spatial demography applications. These challenges include confidentiality issues, scale problems, and the lack of training on spatial analysis in population centers. Although the first and second challenges involve modeling and technical solutions, the latter depends only on demographers’ commitment and willingness to promote change. Several topics for future spatially focused research are also outlined. Finally, the paper makes a strong case regarding the significant contribution that spatial demography can make to the monitoring, evaluation, and implementation of population policies.     

Estimation of average mortality under censoring and truncation

In demography mortality is usually reported through averages over time intervals. If average mortality is estimated from censored or truncated data, then direct methods of estimation may create biases that depend on the censoring or truncation distribution. Such discretization errors may be avoided by estimating survival curves first in continuous time, and then discretizing the estimators. We illustrate the different methods on data of the form obtained from family reconstitution.     

Political demography: Powerful trends under-attended by demographic science

The interconnections between politics and the dramatic demographic changes under way around the world have been neglected by the two research disciplines that could contribute most to their understanding: demography and political science. Instead, this area of ‘political demography’ has largely been ceded to political activists, pundits, and journalists, leading often to exaggerated or garbled interpretation. The terrain includes some of the most politically sensitive and contested issues: alleged demographically determined shifts in the international balance of power; low fertility, population decline, and demographic ageing; international migration; change in national identity; and compositional shifts in politically sensitive social categories and human rights. Meanwhile many governments and non-governmental actors have actively pursued varieties of ‘strategic demography’, deploying fertility, mortality, or migration as instruments of domestic or international policy. Political scientists and demographers could and should use their knowledge and analytic techniques to improve understanding and to moderate excessive claims and fears on these topics.     

Population studies of mortality

Population Studies has become the principal outlet for demographic research on mortality. Many of the advances in the measurement of mortality in data-poor countries were reported in its pages. It has also published most of the influential articles which attempted to make a broad-scale assessment of the sources of mortality change. These include special attention to developments in England and Wales and Sri Lanka. Capitalizing on the widespread availability of demographic surveys, articles in the 1980s featured careful analyses of the demographic correlates of child mortality. Such studies have passed the point of diminishing returns, and declines in child mortality have focused increased attention on conditions among adults. Unfortunately, demography has not developed the means for measuring and analysing adult mortality in underdeveloped countries that are equivalent in their power to methods for studying child mortality.     

Population Studies of Mortality

Population Studies has become the principal outlet for demographic research on mortality. Many of the advances in the measurement of mortality in data-poor countries were reported in its pages. It has also published most of the influential articles which attempted to make a broad-scale assessment of the sources of mortality change. These include special attention to developments in England and Wales and Sri Lanka. Capitalizing on the widespread availability of demographic surveys, articles in the 1980s featured careful analyses of the demographic correlates of child mortality. Such studies have passed the point of diminishing returns, and declines in child mortality have focused increased attention on conditions among adults. Unfortunately, demography has not developed the means for measuring and analysing adult mortality in underdeveloped countries that are equivalent in their power to methods for studying child mortality.     

What demographers can learn from fruit fly actuarial models and biology

Historically demographers have viewed the results of actuarial studies of nonhuman species, particularly those on invertebrates such as fruit flies, as largely irrelevant to investigations on human populations. In this paper I present life table data from large scale studies on the Mediterranean fruit fly, and show that they provide important insights into fundamental aspects of mortality relevant to human populations: the trajectory of mortality at older ages, sex mortality differentials, the concept of maximal life span, and demographic heterogeneity and selection. An overriding theme of the paper is the need for demographers to acquire a heightened awareness of new developments in biology including areas such as evolutionary ecology, experimental demography, and molecular medicine.     

Early-life mortality clustering in families: A literature review

Research on early-life mortality in contemporary and historical populations has shown that infant and child mortality tend to cluster in a limited number of high-mortality families, a phenomenon known as ‘mortality clustering’. This paper is the first to review the literature on the role of the family in early-life mortality. Contemporary results, methodological and theoretical shortfalls, recent developments, and opportunities for future research are all discussed in this review. Four methodological approaches are distinguished: those based on sibling deaths, mother heterogeneity, thresholds, and excess deaths in populations. It has become clear from research to date that the death of an older child harms the survival chances of younger children in that family, and that fertility behaviour, earlier stillbirths, remarriages, and socio-economic status all explain mortality clustering to some extent.     

Population theory—A long view

Any attempt to take a long view of population research, its findings, and applications is bound to raise questions about the state of population theory. Recent research on the history of population thought enables us to include a much more complete account of classical and early modern sources, and of parallel and complementary developments in population biology. This paper considers four major shifts in the conceptual and empirical ambitions of population inquiry over the long term. In general, major conceptual developments in ideas about population reflect major shifts in political and biological theory. The nature of population in European science and society was substantially established before demography emerged as a twentieth-century academic discipline focused chiefly on fertility and mortality. A long view suggests that demography is currently in the course of a shift that constructively re-integrates it with the wider field of scientific and historical population thinking.     

Long-term mortality patterns in Chinese history: evidence from a recorded clan population

Human populations have lived on the earth for millions of years, yet the study of population history only began to be established in the mid-twentieth century. In spite of the considerable progress in the study of historical demography which has since been made, there have been hardly any detailed studies of fertility and mortality before the sixteenth century. This study, by analysing a set of Chinese genealogies, examines long-term mortality patterns in a selected clan population over a period of more than 1000 years. The result shows that, in this selected population, mortality fluctuated around a relatively high level and showed no secular change over the very long period studied. The study also provides a comparison between the mortality patterns found in the selected population and those observed in a much larger Chinese lineage population, as well as those recorded among the British elites born between the sixteenth and the early nineteenth century. Based on the findings of this research, the paper presents some tentative suggestions about long-term mortality changes in Chinese history.     

Ever since gompertz

In 1825 British actuary Benjamin Gompertz made a simple but important observation that a law of geometrical progression pervades large portions of different tables of mortality for humans. The simple formula he derived describing the exponential rise in death rates between sexual maturity and old age is commonly referred to as the Gompertz equation—a formula that remains a valuable tool in demography and in other scientific disciplines. Gompertz’s observation of a mathematical regularity in the life table led him to believe in the presence of a law of mortality that explained why common age patterns of death exist. This law of mortality has captured the attention of scientists for the past 170 years because it was the first among what are now several reliable empirical tools for describing the dying-out process of many living organisms during a significant portion of their life spans. In this paper we review the literature on Gompertz’slaw of mortality and discuss the importance of his observations and insights in light of research on aging that has taken place since then.     

How frailty models can be used for evaluating longevity limits: Taking advantage of an interdisciplinary approach

In this paper we discuss an approach to the analysis of mortality and longevity limits when survival data on related individuals with and without observed covariates are available. The approach combines the ideas of demography and survival analysis with methods of quantitative genetics and genetic epidemiology. It allows us to analyze the genetic structure of frailty in the Cox-type hazard model with random effects. We demonstrate the implementation of this strategy to survival data on Danish twins. We then evaluate the resulting lower bounds for biological limits of human longevity. Finally, we discuss the limitations of this approach and directions of further research.     

Promises and Pitfalls of Using Digital Traces for Demographic Research

The digital traces that we leave online are increasingly fruitful sources of data for social scientists, including those interested in demographic research. The collection and use of digital data also presents numerous statistical, computational, and ethical challenges, motivating the development of new research approaches to address these burgeoning issues. In this article, we argue that researchers with formal training in demography—those who have a history of developing innovative approaches to using challenging data—are well positioned to contribute to this area of work. We discuss the benefits and challenges of using digital trace data for social and demographic research, and we review examples of current demographic literature that creatively use digital trace data to study processes related to fertility, mortality, and migration. Focusing on Facebook data for advertisers—a novel “digital census” that has largely been untapped by demographers—we provide illustrative and empirical examples of how demographic researchers can manage issues such as bias and representation when using digital trace data. We conclude by offering our perspective on the road ahead regarding demography and its role in the data revolution.     

Johann Peter Süssmilch: A German Prophet in Foreign Countries

The clergyman Johann Peter Süssmilch (1707–1767), chaplain to King Frederick II of Prussia, deserves to be called the father of German demography and was recognized as such in his own lifetime in his country of origin and throughout Europe, except possibly in France and Italy. In his Göttliche Ordnung (1741 and 1761–2), he attempted to explain the regularity of vital phenomena as being due to divine intervention. His conception of a ‘divine’ order soon gave way to that of a ‘natural’ order. His life tables, though incorrect, continued to be used by insurance offices well into the nineteenth century. His views about the relationships between mortality on one hand, and fertility and nuptiality on the other led to controversies between Malthus, Sadler and other scholars. Later, his ideas were given a broader economic and social interpretation. Whether as the last representative of ‘primitive’ demography, or the first scientific scholar of the subject, he contributed to the triumph of political arithmetic throughout Europe.     

What is applied demography?

Applied demography has recently gained recognition as an emergent specialization among practicing demographers. We argue that applied demography is intrinsically distinct from basic demography because it exhibits the value-orientation and empirical characteristics of a decision-making science while the latter exhibits the value-orientation and empirical hallmarks of a basic science. Distinguishing characteristics of applied demography are based on the context in which it places precision and explanatory power relative to time and resources as well as the fact its substantive problems are largely exogenously-defined, usually by customers. The substantive problems of basic demography, on the other hand, are largely endogenously-defined, usually by academic demographers. Moreover, basic demography is primarily concerned with offering convincing explanations of demographic phenomena and tends to view time and resources as barriers to surmount in order to maximize precision and explanatory power. This context is very different from the one in which applied demography is embedded, which views explanatory power and precision in terms of doing what is necessary to support practical decision-making while minimizing time and resources. We examine this conceptualization of applied demography in terms of the methods and materials that fall within its purview and discuss some important consequences, including research agendas and training programs. We conclude by posing several important but unanswered questions about the actual and potential scope of applied demography and discuss some of the implications inherent in these questions.An earlier version of this paper was presented at the annual meeting of the Southern Demographic Association, 20 October 1995, Richmond, Virginia, USA.     

The development and use of demographic models

In this review, we first examine two classical demographic models - conventional life tables and stable populations - and a modern generalization of stable population theory; we then discuss mathematical models of conception and birth. These models involve purely mathematical relations in formal demography as opposed to empirical regularities. Next we consider model age schedules of mortality, nuptialitiy, marital fertility, fertility, and migration that are explicitly based on such empirical patterns. We close this empirical section with a discussion of model stable populations, which are based on model life tables. We next examine the use of demographic models in forecasting future mortality, nuptiality, and fertility and in population projection. Following a discussion of microsimulation models, which gives us the opportunity to mention model age schedules of post partum amenorrhoea and of sterility, we close with observations about the purposes and uses of demographic models.     

Famine,Maternal Nutrition and Infant Mortality: A Re-examination of the Dutch Hunger Winter

During the Dutch Hunger Winter (1945), a unique, documented example of mass famine in an industrialized population, total reproductive loss (fetal and infant mortality) among most exposed mothers remained relatively low. This is explained by highly favourable fetal mortality and unfavourable infant mortality. The author traces the pattern of low fetal mortality to the higher levels of ‘embodied health status’ of famine mothers. The high infant mortality of the famine area testifies to the severity of the food and fuel shortage, yet another factor held down the rate of stillbirth. This other factor, it is argued, has a socio-economic character, it is the intrinsic ‘embodied’ nutritional status of the regional population, arising from favourable opportunities for growth and development among successive generations of mothers. This explanation highlights the importance of maternal vitality, (a synthetic, historically variable and culturally determined phenomenon) as a neglected feature of historical demography.