Biosocial models: Can demographers ignore them?

Social demographers must take seriously the challenge to dominant theoretical paradigms that is posed by biosocial models. Accumulating empirical evidence documents the significant contribution of biological variables to the determination of social behaviors, including demographic behaviors. The simplest biosocial models may prove inadequate in social demographic research. More appropriate models may need to allow for causal relationships between biological and social determinants, and for effects that are interactive, non-linear, and discontinuous. While the articulation and testing of such models is unattainable at present, considerable insight can be gained by adding selected biological variables to ongoing demographic research. Demographic surveys should incorporate features of behavioral genetic designs. The chief short-term obstacles to the application of biosocial models in demography are disclinary boundaries; that is, the obstacles are institutional, not scientific.An earlier version of this paper was presented at the Workshop on Biosocial Factors, National Institutes of Health, Bethesda, Maryland, 12 October 1994.     

The nature of gender

I explain a biosocial model of women’s gendered behavior (behavior on which the sexes differ). This model integrates a macro sociological theory with a biological theory derived from primate behavior. The sociological model is designed to explain changes in the relationship between sex and behavior over time or between groups. The biological model is designed to explain individual within-sex variance and between-sex variance in gendered behavior in a cohort. Results from an original study are presented to demonstrate that within-sex variance in women’s gendered behavior is explained well by the primate model. I conclude that human nature is gendered. The implications of this conclusion are explored for demographic and other social science research.     

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.     

One step back in understanding racial differences in birth weight

In recognition of the biological and social connections in demographic processes, demographers have integrated biological factors into their models of population variation. This new effort has tended to focus on the analysis of fertility and mortality. Edwin J.C.G. van den Oord and David C. Rowe's article, "Racial Differences in Birth Health Risk: A Quantitative Genetic Approach," published in the August 2000 issue of Demography, is part of this effort. These authors use race as a proxy for genetic variation, which subverts even the most positive attempts to understand the impact of genetic variation on demographic processes. The authors' statistical results restate their anachronistic theory of race using latent variables that are not open to empirical testing. Although new data increase the opportunities for the examination of the relationship between biology and demographic processes researchers must be vigilant not to commit the errors of the past by misusing race as a variable.     

Childbearing Postponement and Child Well-being: A Complex and Varied Relationship?

Over the past several decades, U.S. fertility has followed a trend toward the postponement of motherhood. The socioeconomic causes and consequences of this trend have been the focus of attention in the demographic literature. Given the socioeconomic advantages of those who postpone having children, some authors have argued that the disadvantage experienced by certain groups would be reduced if they postponed their births. The weathering hypothesis literature, by integrating a biosocial perspective, complicates this argument and posits that the costs and benefits of postponement may vary systematically across population subgroups. In particular, the literature on the weathering hypothesis argues that, as a consequence of their unique experiences of racism and disadvantage, African American women may experience a more rapid deterioration of their health which could offset or eventually reverse any socioeconomic benefit of postponement. But because very few African American women postpone motherhood, efforts to find compelling evidence to support the arguments of this perspective rely on a strategy of comparison that is problematic because a potentially selected group of older black mothers are used to represent the costs of postponement. This might explain why the weathering hypothesis has played a rather limited role in the way demographers conceptualize postponement and its consequences for well-being. In order to explore the potential utility of this perspective, we turn our attention to the UK context. Because first-birth fertility schedules are similar for black and white women, we can observe (rather than assume) whether the meaning and consequences of postponement vary across these population subgroups. The results, obtained using linked UK census and birth record data, reveal evidence consistent with the weathering hypothesis in the United Kingdom and lend support to the arguments that the demographic literature would benefit from integrating insights from this biosocial perspective.     

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.     

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.     

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.     

A Comparative Evaluation of Error and Bias in Census Tract-Level Age/Sex-Specific Population Estimates: Component I (Net-Migration) vs Component III (Hamilton–Perry)

While the housing-unit method continues to be the preferred method nationwide for producing small-area population estimates, this procedures lacks a method for making age/sex-specific estimates. This paper reports evaluation research on implementation of component-based methods for estimating census tract populations with age/sex detail. Two alternatives are explored: (1) the Component I method relying upon estimates of births, deaths, and net-migration and (2) the Component III method relying solely upon 1990 and 2000 Census counts. From an April 1, 2000 base, each method is used to make estimates moving forward to an April 1, 2010 estimate that is compared to the results of the 2010 Census. The two methods are compared in terms of accuracy and bias using both absolute and algebraic mean and median percentage errors. Results are reviewed and discussed in light of their implications for applied demographers tasked with making small-area demographic estimates.     

The demography of disadvantage

This paper discusses the contribution that demographers can make to the study of disadvantage. Demographers from Malthus onwards have been interested in analysing disadvantage through the lens of demographic variables, notably fertility, mortality and population growth, and their effect on poverty and welfare, both at an aggregate level and in terms of intra-household differences in well-being. The methodology of demography, including the concern with getting denominators right, cohort analysis and standardization procedures, can contribute to the analysis of disadvantage in many different ways. As examples, this paper highlights two issues: that of inequality of access to quality education, and the social and economic disadvantage faced by Indigenous Australians. The goal of understanding the causes of disadvantage with a view to reducing it may be best served through multidisciplinary efforts, in which demographers should play a role.     

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.     

A comparison and latent variable test of two fertile ideas

Perhaps the two most important recent strands in the economics of fertility have been developed by Becker and Easterlin. Both suggest possible biases due to unobserved variables. Becker earlier emphasized changing shadow prices for child quantity and quality and, more recently, intergenerational serially-correlated endowments, all with given preferences. Easterlin has focused on intergenerational serially-correlated preferences. Some demographers have suggested that the Becker and Easterlin approaches are converging and may not be identified from each other.We demonstrate that while the Becker endowment and Easterlin taste models can be expressed in terms of the same variables, it is possible to identify each of the models because of different signs in a latent variable system that uses information from individuals, siblings, and cousins. Estimates of this model are consistent with the Easterlin, but not the Becker formulation. But neither model results in significant income coefficient estimates.The authors thank NIH for research support and Alan Mathios for excellent research assistance. The usual disclaimer applies.     

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.     

New frontiers in demography and social psychology

The topics of demography are those of human fate: birth, illness, marriage, occupation, and death. The methods of demography therefore relate global rates to major events, submerging the individual decision. The social psychologist observes the regularities of people's behavior in different social conditions and builds models from individual decisions. Since he looks at patterns independent of the event, the kind of event does not matter, and he tends to concentrate on trivial events which are amenable to research.To the degree that man has obtained control over his environment, he is able to look at demographic events as less than fate. Social conditions have also given more control to the individual over many events over which he had no control previously, such as choice of a marriage partner or an occupational career. Thus, the classical methods of demography are frequently insufficient to deal with demographic data, and abrupt changes may occur because of vagaries of individual decisions. The more the demographic trends can be affected by individual decisions, the more the methods of social psychology become useful in understanding changes in population composition.The possibilities of micro-demography, of building up demographic trends from individual decisions, become stronger as more individual control can be exerted over the events. Such disparate events as control of infectious disease, air pollution, birth control, civil rights, and changes in the educational system and occupational structure have given individuals more control over different demographic variables, made the study of individual decisions with demographic consequences important, and led to joint efforts by demographers and social psychologists.     

Research Note: What Counts as a House? Comparing 2010 Census Counts and Administrative Records

As a tool for fulfilling data needs for small area (subcounty) analysis, demographers are increasingly turning to administrative records such as building permits and tax assessor records as a source of data for use in producing small area demographic estimates. While Census counts are considered to be the “gold standard,” administrative records provide a fine level of spatial detail and a valuable source of information for intercensal years. However, there is uncertainty about the quality of administrative records data for use in estimation. This analysis builds upon earlier research by comparing administrative records-based housing unit estimates developed during the 2000s decade with housing counts from the 2010 Census in San Diego County. Results show that both administrative records and Census counts have strengths and weaknesses that should be understood by the data user.     

Biological and social determinants of body size across the life span

The accuracy of demographic models designed to project future trends of population-level health and disease can be improved by incorporating biological data. One barrier to this process are quantitative characteristics of the data themselves. Biological data are characteristically time-dependent phenomena that behave in a nonlinear fashion. To develop accurate projections of the morbidity, disability, and mortality experience among future cohorts in late life, research needs to focus on development of models that create the opportunity to distinguish all-or-none, boundaries, and latency aspects of biological factors driving demographic phenomena, development of methods to identify time-dependent effects, and development of genetically informative samples. This presentation focuses on the biology of adult body size, its behavior as a variable in statistical analyses, and strategies for the incorporation of this variable into demographic models of population aging in the United States. First, several examples of generally observed quantitative characteristics of biological variables are reviewed. To illustrate the nonlinear character of biological data, three general patterns of change with aging are presented. Next, issues concerning the measurement of body size are discussed. Scenarios describing body size over the adult life span are described. By the end of this process, recommendations for starting a dialogue between researchers interested in biological endpoints (individual weight change, disease risk) and those interested in demographic outcomes (population-level disease and disability issues) using body size will be presented.     

What population studies can do for business

Demographers have a fundamental role to play in planning for the future. They possess a wide range of skills concerning the number, diversity and spatial distribution of the population, which are of value to business concerns. The role of demographers in analysis of census data is of special value. This paper discusses the specific skills acquired by demographers and provides examples of how these skills can be very useful and important in planning in both the private and public sectors. Finally the future of demographic training in Australia is considered by contrasting the APA membership with that of the PAA and considering the need for developing more teaching in demography at Australian tertiary institutions. The role of the APA in improving the status of demography as an important tool for corporate planning for the future is also emphasized.     

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.     

Economic analysis of age at first marriage

A subject of great interest to demographers is to relate the timing of demographic events to individual characteristics and environmental variables. Static models of marriage tend to give corner solutions, the choice of marriage or remaining single. This article develops an economic model of marriage which gives interior solutions to the optimum age at first marriage and which does not include an explicit argument about the age at marriage in the utility function. In theoretical analysis, life cycle model is modified to capture different aspects of the decision of when to get married. Results from empirical analysis support implications derived from the theoretical analysis.     

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.