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.     

美国的人口学兴衰及其决定因素

从社会建构主义视角回顾和分析美国人口学的发展历程,展现人口学在不同历史时期的发展状况。人口学作为一门学科,其学科特色是人口学者们在特定的历史条件下人为建构出来的。人口学本身是不断的调整和发展的,人口学者们应注意到这一现象,不要被人口学所谓的内在学科特色所束缚。     

Reconsidering the Northwest European Family System: Living Arrangements of the Aged in Comparative Historical Perspective

During the past four decades, historians and demographers have argued that historical Northwest Europe and North America had a unique weak‐family system characterized by neolocal marriage and nuclear family structure. This analysis uses newly available micro‐data from 84 historical and contemporary censuses of 34 countries to evaluate whether the residential behavior of the aged in historical Northwest Europe and North America was truly distinctive. The results show that with simple controls for agricultural employment and demographic structure, comparable measures of the living arrangements of the aged show little systematic difference between nineteenth‐century Northwest Europe and North America and twentieth‐century developing countries. These findings cast doubt on the hypothesis that Northwest Europeans and North Americans had an exceptional historical pattern of preference for nuclear families.     

The impact of incomplete geocoding on small area population estimates

Small-area population estimates are often made using geocoded address data in conjunction with the housing-unit method. Previous research, however, suggests that these data are subject to systematic incompleteness that biases estimates of race, ethnicity, and other important demographic characteristics. This incompleteness is driven largely by an inability to complete georeference address-based datasets. Given these challenges, small-area demographers need further, and to date largely unavailable, information on the amount of error typically introduced by using incompletely geocoded data to estimate population. More specifically, we argue that applied demographers should like to know if these errors are statistically significant, spatially patterned, or systematically related to specific population characteristics. This paper evaluates the impact of incomplete geocoding on accuracy in small-area population estimates, using a Vintage 2000 set of block-group estimates of the household population for the Albuquerque, NM metro area. Precise estimates of the impact of incomplete geocoding on the accuracy of estimates are made, associations with specific demographic characteristics are considered, and a simple potential remediation based on Horvitz-Thompson theory is presented. The implications of these results for the practice of applied demography are reviewed.     

Geographic Information Systems and Spatial Data Processing in Demography: a Review

This paper reviews the use of geographic information systems (GIS) software for spatial data processing in demography. The review begins with an introduction to GIS. Next, it traces the three major types of spatial data problems confronting demographers: the geocoding and geoprocessing of microdata, estimation of detailed population surfaces, and combining data aggregated to incompatible zone systems. GIS and non-GIS solutions to these problems are contrasted, with examples from published research. Spatially pre-processed datasets available to demographers are then discussed. The author concludes by noting that the solutions GIS provides to previously intractable data problems in spatial demography might encourage a focus on dynamic processes of population change in local areas.     

An Evaluation of Persons per Household (PPH) Estimates Generated by the American Community Survey: A Demographic Perspective

The American Community Survey (ACS) is a U.S. Census Bureau product designed to provide accurate and timely demographic and economic indicators on an annual basis for both large and small geographic areas within the United States. Operational plans call for ACS to serve not only as a substitute for the decennial census long-form, but as a means of providing annual data at the national, state, county, and subcounty levels. In addition to being highly ambitious, this approach represents a major change in how data are collected and interpreted. Two of the major questions facing the ACS are its functionality and usability. This paper explores the latter of these two questions by examining “persons per household (PPH),” a variable of high interest to demographers and others preparing regular post-censal population estimates. The data used in this exploration are taken from 18 of the counties that formed the set of 1999 ACS test sites. The examination proceeds by first comparing 1-year ACS PPH estimates to Census 2010 PPH values along with extrapolated estimates generated using a geometric model based on PPH change between the 1990 and 2000 census counts. Both sets of estimates are then compared to annual 2001–2009 PPH interpolated estimates generated by a geometric model based on PPH from the 2000 census to the 2010 census. The ACS PPH estimates represent what could be called the “statistical perspective” because variations in the estimates of specific variables over time and space are viewed largely by statisticians with an eye toward sample error. The model-based PPH estimates represent a “demographic perspective” because PPH estimates are largely viewed by demographers as varying systematically and changing relatively slowly over time, an orientation stemming from theory and empirical evidence that PPH estimates respond to demographic and related determinants. The comparisons suggest that the ACS PPH estimates exhibit too much “noisy” variation for a given area over time to be usable by demographers and others preparing post-censal population estimates. These findings should be confirmed through further analysis and suggestions are provided for the directions this research could take. We conclude by noting that the statistical and demographic perspectives are not incompatible and that one of the aims of our paper is to encourage the U.S. Census Bureau to consider ways to improve the usability of the 1-year ACS PPH estimates.     

The Great Emigration of 1841: Recruitment for New South Wales in British Emigration Fields

A survey of papers reporting the use of ethnographies in three population journals and an examination of two case studies show that the criticisms made by anthropologists and others of demographers’ use of ethnographies are well founded. In their use of these accounts, demographers tend to present an excessively static view of social organization, to use ethnographic evidence selectively to support other findings, to be indifferent to how long ago an ethnography was produced, to take for granted the validity of the ethnographic evidence, to ignore the broader historical context in which the ethnography was produced, and to be unaware of the ways in which demographic evidence can be used at all stages of the research process. The adoption of anthropologists’ suggestions for establishing the plausibility and credibility of ethnographic evidence could improve the value of the contribution made by these studies to demographic research and theory.     

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.     

Chinese genealogies as a source for demographic research: A further assessment of their reliability and biases

Genealogy is the written record of family or lineage members descended from a common ancestor or ancestors. These materials have long been used by demographers in their investigation of past demographic behaviour. Most available genealogies, however, are the records of members of surviving patrilineages. Among the many reasons why these patrilineages have avoided extinction is the fact that they have usually experienced favourable demographic conditions.. In consequence, their genealogies could be a biased data source if used in the study of the history of the whole population. This paper examines this issue, using evidence on the historical experience of the Chinese population and computer micro-simulation.     

Developmental Idealism and Cultural Models of the Family in Malawi

This paper examines the extent to which developmental idealism has been disseminated in Malawi. Developmental idealism is a set of beliefs and values about development and the relationships between development and family structures and behavior. Developmental idealism states that attributes of societies and families defined as modern are better than attributes defined as traditional, that modern societies help produce modern families, that modern families facilitate the achievement of modern societies, and that the future will bring family change in the direction of modernity. Previous research has demonstrated that knowledge of developmental idealism is widespread in many places around the world, but provides little systematic data about it in sub-Saharan Africa or how knowledge of it is associated with certain demographic characteristics in that region. In this paper, we address this issue by examining whether ordinary people in two settings in Malawi, a sub-Saharan African country, have received and understood messages that are intended to associate development with certain types of family forms and family behaviors. We then examine associations between demographic characteristics and developmental idealism to investigate possible mechanisms linking global discourse about development to the grassroots. We analyze data collected in face-to-face surveys from two samples of Malawian men in 2009 and 2010, one rural, the other in a low-to-medium income neighborhood of a city. Our analysis of these survey data shows considerable evidence that many developmental idealism beliefs have been spread in that country and that education has positive effects on beliefs in the association between development and family attributes. We also find higher levels of developmental idealism awareness in the urban sample than we do in the rural sample, but once dissimilarities in education and wealth between the two samples are controlled, awareness levels no longer differed between urban and rural respondents. We explore how these beliefs intersect with longstanding local values and beliefs in Malawi.     

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.     

Demography and the environment

Demographers' interest in the environment has generally been enmeshed in broader issues of population growth and economic development. Empirical research by demographers on environmental issues other than natural-resource constraints is limited. In this paper, I briefly review past demographic thinking about population and the environment and suggest reasons for the limited scope of demographic research in this area. Next, I describe more recent demographic research on the environment and suggest several newer areas for demographic research. Finally, I consider the future of research on the environment in the field of demography.     

On the use of the truncated Gompertz distribution and other models to represent the parity progression functions of high fertility populations

The Gompertz distribution, developed from the mortality “law”; long used by actuaries and demographers promises to be a useful distribution for many other demographic purposes as well. The continuous distribution can also be adapted to represent discrete data commonly encountered in demographic work, and maximum likelihood estimates of the two parameters are easily calculated using formulae developed in this paper, whether those data be continuous or discrete, truncated below or provided with observations in a final open‐ended interval.

The distribution is unimodel. The use of the truncated form of the distribution, however, allows the researcher to fit it to a wider range of observed distributions, including many for which the density function is monotonic decreasing.

Empirical studies using parity progression data of two high fertility populations indicate that the truncated Gompertz distribution in its discrete form provides a good overall picture of the parity distribution. Interestingly, the simple method of partial sums, commonly employed to fit the Gompertz function, appears to provide parameter estimates which are close to those estimated by maximum likelihood.     

Cultural and Socioeconomic Influences on Divorce During Modernization: Southeast Asia, 1940s to 1960s

The conventional model of a rising divorce rate during the process of modernization is a staple element of the sociological theory of the family. This generalization is challenged, however, by traditional high‐divorce societies, primarily in Islamic Southeast Asia, which have experienced a decline in divorce with modernization. In this study, based on micro‐level survey data, the authors explore the social roots of marital disruption in Indonesia and Malaysia and in another Southeast Asian society, Thailand, which has not been identified as a high‐divorce society. Comparable survey data from the 1970s (from the World Fertility Survey) allow for an in‐depth analysis of traditional patterns of divorce before the rapid modernization of recent decades. Two major findings emerge from the multivariate analysis. First, there is a common pattern across all three societies of higher levels of divorce among “traditional” women—those who live in rural areas, marry at young ages, and have lower levels of education. Second, the authors find significant sociocultural (ethnic, regional, religious) differentials in divorce within each country that cannot be explained by demographic and socioeconomic composition. They present an interpretation of how moderately high levels of divorce were accommodated in traditional Southeast Asian societies.     

An evaluation of demographers' use of ethnographies

A survey of papers reporting the use of ethnographies in three population journals and an examination of two case studies show that the criticisms made by anthropologists and others of demographers' use of ethnographies are well founded. In their use of these accounts, demographers tend to present an excessively static view of social organization, to use ethnographic evidence selectively to support other findings, to be indifferent to how long ago an ethnography was produced, to take for granted the validity of the ethnographic evidence, to ignore the broader historical context in which the ethnography was produced, and to be unaware of the ways in which demographic evidence can be used at all stages of the research process. The adoption of anthropologists' suggestions for establishing the plausibility and credibility of ethnographic evidence could improve the value of the contribution made by these studies to demographic research and theory.     

Assessing the Need for a New Medical School: A Case Study in Applied Demography

This case study illustrates how applied demographers operate in a politically charged context of competing interests—here, justifying the decision to locate a new public medical school in one medically underserved region rather than another. We show how to use demographic and other data to gauge the magnitude of future demand for physicians; formulate demographic assumptions about the future to serve decisionmakers’ needs; and frame information to help improve decision making through objective analysis. We detail the steps in projecting future physicians per capita using a method based on the economic concept of physician demand rather than the social concept of need. Our method is computationally simple, intuitive, and easily understood by policymakers. Our case study offers applied demographers a practical approach to physician workforce planning and can be used as an instructional exercise for students, assigned to replicate these projections elsewhere and distill their implications.     

The Limits to Low Fertility: A Biosocial Approach

In light of 30 years of below‐replacement fertility in many industrialized societies, demographers are asking whether fertility could drop even further, or whether there is a “floor” below which it will not fall. A key unanswered question is whether there may be a variable biological component to fertility motivation which ensures that we continue to reproduce. Drawing on evidence from evolutionary biology, ethology, quantitative genetics, developmental psychobiology, and psychology, the article argues that our evolved biological predisposition is toward nurturing behaviors, rather than having children per se. Humans have the unique ability to be aware of such biological predispositions and translate them into conscious, but nevertheless biologically based, fertility motivation. It is likely that we have already reached the limits to low fertility since this “need to nurture,” in conjunction with normative pressures, ensures that the majority of women will want to bear at least one child. A sketch for a biosocial model of fertility motivation is outlined.     

Areal Interpolation of Population Counts Using Pre-classified Land Cover Data

The need to combine spatial data representing sociodemographic information across incompatible spatial units is a common problem for demographers. A particular concern is computing small area trends when aggregation zone boundaries change during the trend interval. To that end, this study provides an example of dasymetric areal interpolation using the pre-classified land cover data available through the US Geological Survey’s National Land Cover Dataset (NLCD) program. Areal interpolation of population estimates is preferable to traditional reaggregation techniques, and the use of land cover data as a weighting factor in interpolated estimation has been shown in earlier studies to be highly accurate. In this study, the NLCD data set performs well and, because it requires no classification, it compares favorably with other land cover data sets for areal interpolation when considered on the basis of accuracy, precision and ease of use.     

Combining registration-system and survey data to estimate birth probabilities

With the widespread availability of event-history data, demographers have increasingly eschewed registration-system data in favor of survey data. We propose instead using survey and registration-system data in combination, via a constrained maximum-likelihood framework for demographic hazard modeling. As an application, we combine panel survey data and birth registration data to estimate annual birth probabilities by parity. The general fertility rate obtained from registration-system data constrains the weighted sum of parity-specific birth probabilities. The variances about the parity-specific birth probabilities are halved when registration-system data are used to constrain the estimates. Other demographic applications are discussed.     

Estimating Nantucket’s Effective Population

Population Research and Policy Review - This paper extends demographers’ traditional approaches to estimating local populations using symptomatic data. We augmented those approaches in order...