Back to home page

United States of America (Wilmington, Delaware) 88

POPULATION RESEARCH AND POLICY REVIEW

1994 - VOLUME 13, NUMBER 4

96.88.1 - English - Susan L.D. ROVI, Department of Sociology, Rutgers University, New Brunswick, NJ (U.S.A.) Taking "no" for an answer: Using negative reproductive intentions to study the childless/childfree (p. 343-365)

In this paper, the author argue for an approach to the study of the childless/childfree based on negative reproductive intentions. To forward this argument, I present the theoretical justification for a concept based on taking 'no' for an answer, demonstrating that such an approach provides both a valid and reliable measure of intended childlessness. Building on earlier work by researchers of childlessness and reacting to their concerns that most studies have not employed either representative sampling or multivariate methods, the author incorporates both in empirical tests of this approach. Using 11 years of the General Social Survey and a Trichotomous Logit Analysis, the resulting model simultaneously assesses the effects of the independent variables on the probabilities that the married women in this sample are childless/childfree. This analysis is generally consistent with hypotheses generated from earlier studies and their findings on the correlates of childlessness, thereby supporting the literature that says the voluntarily childless are a distinct group. In effect, the viability of the concept is substantiated, enabling its use in future research. Because this conceptualization recognizes the dynamics of reproductive intentions, it provides a way to better understand the current social milieu of individuals who say they do not intend to parent. (UNITED STATES, VOLUNTARY CHILDLESSNESS, SURVEYS, METHODOLOGY)

96.88.2 - English - Stephan F. GOHMANN, Department of Economics, University of Louisville (U.S.A.), and Robert L. OHSFELDT, School of Public Health, University of Alabama at Birmingham (U.S.A.) The dependent tax exemption, abortion availability, and US fertility rates (p. 367-381)

The impact of the personal income tax dependent exemption, abortion availability, and other factors on fertility rates is analyzed. US time series data for 1915-88 are used in the empirical model. The results indicate that greater abortion availability in the USA is associated with lower fertility. A higher value of the dependent exemption generally is associated with higher fertility, but the magnitude and significance of the effect is sensitive to specification choice. The results suggest that restricting abortion availability in the USA will increase the fertility rate, but a change in the tax value of the dependent exemption will have a less predictable impact on fertility. (UNITED STATES, FERTILITY DETERMINANTS, TAXES, ABORTION POLICY)

96.88.3 - English - Allan F. ABRAHAMSE, Peter A. MORRISON, The RAND Corporation (U.S.A.), and Nancy Minter BOLTON, Bolton Associates (U.S.A.) Surname analysis for estimating local concentration of Hispanics and Asians (p. 383-398)

Surname analysis is a potentially useful technique for identifying members of particular racial, ethnic, or language communities within a population. We review the existing state of the art for identifying persons of Hispanic or Asian origin, based on surnames distinctive of each group. We describe the logic of surname analysis, profile several available surname dictionaries, and illustrate their applications in local redistricting. Results of our ongoing validation studies suggest promising future directions for improving accuracy and broadening applications. (UNITED STATES, SUB-POPULATION, POPULATION DISTRIBUTION, GEOGRAPHICAL DISTRIBUTION, METHODOLOGY, ETHNIC GROUPS, SURNAME)

96.88.4 - English - Edward G. STOCKWELL, Franklin W. GOZA, Yunan JIANG and Verl O. LUSE, Department of Sociology, Bowling Green State University, Bowling Green, Ohio (U.S.A.)

Trends in the relationship between socioeconomic status and infant mortality in metropolitan Ohio, 1960-1990 (p. 399-410)

This paper presents the results of an ecological analysis of the relationship between infant mortality and economic status in metropolitan Ohio at four points in time centering on the censuses of 1960, 1970, 1980 and 1990. The basic unit of analysis is the census tract of mother's usual residence, with economic status being determined by the percentage of low income families living in each tract. For each period, the census tracts were aggregated into broad income groups and three-year average infant mortality rates were computed for each area, by age, sex, race and exogenous-endogenous causes of death. The most important conclusion to be drawn from the data is that in spite of some very remarkable declines in infant mortality for all socioeconomic groups since 1960, there continues to be a very clear and pronounced inverse association between income status and infant mortality. Indeed, there is some evidence to suggest that it is stronger in 1990 than it was three decades earlier. The general inverse association is observed for both sexes, for whites and nonwhites, and for all major causes of death. At the same time, the data reveal notable variations in the pattern of the relationship over time, as well as several differences between whites and nonwhites in the nature and magnitude of the relationship. Some macro-economic hypotheses are offered to explain these temporal and racial differences in the pattern of the relationship between economic status and infant mortality. (UNITED STATES, METROPOLIS, INFANT MORTALITY, SOCIO-ECONOMIC STATUS)

MARCH 1995 - VOLUME 14, NUMBER 1

96.88.5 - English - Emily ROSENBAUM, Fordham University, Bronx, New York, (U.S.A.) The making of a ghetto: Spatially concentrated poverty in New York City in the 1980s (p. 1-27)

In recent years a debate has arisen over which of two mechanisms - class selective household mobility or spatially focused increases in poverty - has been the driving force in concentrating poverty in certain inner-city neighborhoods. This paper utilizes a multivariate analysis to identify the processes underlying areal income-class transition in New York City during 1978-1987, and the areal characteristics that predict a consistent path of change. By anchoring the analysis at the level of the individual housing unit, this study disentangles the competing mechanisms of poverty concentration and demonstrates that both selective mobility and shifts in income class contribute to areal income-class transition, but that the latter mechanism accounts for a greater amount of change. Further, after controlling for the proportion of minority residents and public housing units in the area, the results show that location in poor areas is associated with poor in-movement, nonpoor out-movement, and downward shifts in the income class among long-term residents. These mutually reinforcing processes lead to continued decline in extreme- and high-poverty areas, while processes in the opposite direction sustain the economic vitality of low-poverty areas. (UNITED STATES, POVERTY, URBAN AREAS, RESIDENTIAL MOBILITY, IMPOVERISHMENT)

96.88.6 - English - Peter L. DOAN, Florida State University, Urban and Regional Planning, Tallahassee, Florida (U.S.A.) Population density, urban centrality, and agricultural intensification in Jordan (p. 29-44)

This paper explores the relationship between population growth, agricultural production, and urban development. Ongoing debate in the literature regarding the relationship between population and economic development is restricted by the limited availability of time series data and the difficulty of evaluating causality using cross-sectional data. This analysis uses the special case of Jordan with its massive refugee flows to evaluate the influence of a sudden and exogenous change in population in urban areas on the intensification of agricultural production. Spearman Rank Order correlations are calculated from time series data to show that the districts which experienced the most rapid population growth and increases in population density also exhibited the largest increases in agricultural intensity. Cross-sectional analysis in which measures of agricultural intensification were predicted by population density and urbanization factors reveals a significant interaction between density and urban centrality, where 'centrality' is an indicator of the accessibility of urban goods to rural communities. The results suggest that population density has a strongly positive effect on agricultural intensity in areas with few urban goods and services available, whereas the influence of population density on agricultural intensity is substantially reduced in areas with a greater diversity of urban goods and services. (JORDAN, POPULATION DENSITY, URBANIZATION, AGRICULTURE)

96.88.7 - English - Moshe HARTMAN and Harriet HARTMAN, Ben Gurion University of the Negev, Beer-Sheva (Israel) Long-term effects of international migration: Lessons from Israel (p. 45-69)

The paper shows that characteristics of immigrants at the time of immigration affect both long-term occupational achievements and income at the end of the labor force career, after age 59. Data representing 174,000 Jewish males 60 and older from a 1985 survey by the Israeli Central Bureau of Statistics are analyzed to show how the timing of immigration, the number of years in the country, age at immigration, country of origin, and educational resources at time of immigration are related to years in the labor force in the host country, occupational achievement, pension entitlement and income after age 59. Both direct and indirect effects are analyzed. The results show the importance of immigration characteristics on long-term socioeconomic adjustment, and the necessity of considering social status over the life course as an indicator of long-term immigrant adjustment. Decomposition of the effect of country of origin pinpoints what characteristics at time of immigration influence social status differences in ethnic groups at older ages. The discussion includes a number of methodological implications for future studies in immigration. (ISRAEL, IMMIGRANT WORKERS, OLDER WORKERS, SOCIO-ECONOMIC STATUS)

96.88.8 - English - Ali A. PAYDARFAR, School of Public Health, University of North Carolina, Chapel Hill, NC (U.S.A.), and Reza MOINI, Statistical Center of Iran, TŽhŽran (Iran) Modernization process and fertility change in pre- and post-Islamic Revolution of Iran. A cross-provincial analysis, 1966-1986 (p. 71-90)

The purpose of this paper is to examine some of the possible causal links between modernization forces and fertility patterns of the Iranian provinces during three time periods, 1966, 1976 and 1986. A modernization scale was constructed using Iranian census data. Six indicators of industrialization, urbanization and universal education were used to develop the scale. The ratio of children under 5 years per women 15 to 44 years old was used as a measure of fertility. The findings show that modernization has proceeded upward in an almost consistent pattern in all the provinces during 1966-1986. The Islamic Revolution and Iran-Iraq War not only did not disrupt the modernization trend, it seems that both events accelerated the rate of change. The modernization indicators, individually and collectively, were significantly and inversely correlated with fertility ratios. However, the fertility ratios of the provinces substantially increased in the decade of 1976 to 1986. Our thesis is that the elimination of the national family planning program which happened in the early part of the post-Islamic Revolution had significant effect on the fertility increase of the period 1976 to 1986. The current active family planning program of the Islamic Republic of Iran suggests that the fertility rate of Iran, very likely, will decline in the near future if the current modernization trend and fertility regulation policy continue. (IRAN, PROVINCES, MODERNIZATION, FERTILITY, FAMILY PLANNING PROGRAMMES)

96.88.9 - English - Dominique MEEKERS, Population Research Institute and Department of Sociology, The Pennsylvania State University, University Park, PA (U.S.A.), Anastasia GAGE, Demographic and Health Surveys, Macro International, Inc., Calverton, MD (U.S.A.), and Li ZHAN, Population Research Institute and Department of Sociology, The Pennsylvania State University, University Park, PA (U.S.A.)

Preparing adolescents for adulthood. Family life education and pregnancy-related school expulsion in Kenya (p. 91-110)

Pregnancy-related school dropouts have become a matter of public concern throughout sub-Saharan Africa. In most cases, schoolgirls who become pregnant either have to resort to unsafe illegal abortions, or they face official school expulsion. Because girls who drop out of school due to pregnancy usually do not return to school to complete their education after the birth of their child, their opportunities for socioeconomic advancement are limited. Many African governments have included family life education programs in the school curriculum in an attempt to educate adolescents about the consequences and responsibilities associated with sexual activity. The high rates of schoolgirl pregnancies suggest that these programs have their shortcomings, and indicate that educational policies should attempt not only to reduce the incidence of schoolgirl pregnancies, but also to assist pregnant schoolgirls to complete their education. In this paper, we use data from a sample of 154 Kenyan primary and secondary schools to study differentials in the extent to which various types of schools are affected by pregnancy-related school dropouts, and to examine the opinions of the head teachers regarding teaching about contraceptive methods and readmittance of pregnancy-related dropouts. (KENYA, ADOLESCENT PREGNANCY, EDUCATIONAL DROPOUTS, FAMILY LIFE EDUCATION)

96.88.10 - English - Robert WORTHAM, North Carolina Central University, Durham, NC (U.S.A.) Prospects for fertility reduction and projections for future population growth in Kenya (p. 111-135)

In 1979 Kenya's annual rate of natural population growth was 3.8%. Data from the 1989 Kenya Demographic and Health Survey indicate that significant decreases in fertility levels were experienced during the 1980s. Factors associated with conditions supportive of high fertility in Kenya are discussed, and progress toward attaining significant fertility reduction thresholds during the 1980s is assessed. Findings from recent fertility surveys are presented, and 1969-1989 national level family planning data are evaluated. Four population projections for 1985-2025 are presented and analyzed. One projection is based on official government growth targets; two are based on estimates provided by the United Nations and the Population Reference Bureau, and a fourth projection is based on the assumption that Kenya will attain an annual natural population growth rate of less than 1% by the year 2025. Each projection assumes that fertility declines will be experienced. Kenya's prospects for reducing the annual population growth rate to 1% within the next sixty years and a cost-sharing development policy are addressed briefly in the concluding section. Recent data suggest that Kenya will probably not complete the demographic transition before the year 2050, but Kenya should continue to move through the transition stage. (KENYA, DEMOGRAPHIC TRANSITION, FERTILITY DECLINE, NATURAL INCREASE, POPULATION PROJECTIONS)

JUNE 1995 - VOLUME 14, NUMBER 2

96.88.11 - English - Thomas J. ESPENSHADE and Dolores ACEVEDO, Office of Population Research, Princeton University, Princeton, NJ (U.S.A.) Migrant cohort size, enforcement effort, and the apprehension of undocumented aliens (p. 145-172)

This article examines macro-structural conditions that affect time trends in aggregate probabilities of undocumented alien apprehension along the Mexico-US border. We show that the number of migrants attempting to cross the border illegally in a given period and the level of effort expended by the INS to apprehend undocumented migrants are principal determinants of apprehension probabilities. Our findings differ from those in earlier work by Donato, Durand, and Massey who argue that individual, household, and community factors are not significant predictors of apprehension probabilities and conclude that escaping INS detection at the border is essentially a random process unrelated to personal traits or to enforcement provisions of the 1986 Immigration Reform and Control Act. Although Donato et al. recognize that apprehension probabilities are affected by the size of the US Border Patrol budget and the number of personnel, they omit these larger structural factors from consideration. Instead, they introduce annual dummy variables to control for macro-structural forces. This approach is unsatisfactory because it confounds the effects of numbers explanatory factors. We conclude that one implication for future research is that it is worth modeling the effects of individuals' characteristics on apprehension probabilities by including as predictors an estimate of the flow of undocumented migrants and measures of INS border enforcement effort. Controlling explicitly for three macrostructural conditions may disclose the importance of some individual-level factors that would otherwise be obscured. (UNITED STATES, MEXICO, ILLEGAL MIGRATION, MIGRATION LEGISLATION, POLICE)

96.88.12 - English - Karen A. WOODROW-LAFIELD, Center for Social and Demographic Analysis, State University of New York at Albany, Albany, NY (U.S.A.)

An analysis of net immigration in census coverage evalution (p. 173-204)

National surveys monitored growth in the foreign-born population for the 1980s, especially net undocumented migration's continuing role, but the 1990 census portrayed an even larger foreign-born population than these surveys. Undercoverage in 1990 could have been higher than initially presented because preliminary studies may have insufficiently accounted for decadal net immigration. Assumptions intended to maintain a high undocumented undercount performed poorly when census counts of foreign-born residents became known. Any point estimate for net undocumented migration, calculated as a residual, is likely to be biased by assumptions and data gaps for components of calculating net legal immigration, especially in the direction of underestimation. A reasonable statement is that at least 2.1-2.4 million undocumented residents were enumerated in the 1990 census. The number of unenumerated undocumented residents may easily have ranged between 0.5 million and 3.0 million, and a narrower range of 1 million to 2 million is plausible. Despite the importance of undocumented migration measurement for census evaluation and policy purposes, differences among various undocumented estimates are more likely to stem from discrepancies in universe, reference dates, or individual judgement, rather than analytic refinement. Better measurement of the foreign-born population or its census coverage would aid in setting upper limits on net undocumented migration. (UNITED STATES, ILLEGAL MIGRATION, MIGRATION BALANCE, UNDERESTIMATION, POPULATION CENSUSES)

96.88.13 - English - C. Jack TUCKER, Department of Sociology, Winthrop University, Rock Hill, SC (U.S.A.), Larry LONG, Housing and Household Economic Statistics Division, US Bureau of the Census, Washington, DC (U.S.A.), and Jonathan MARX, Department of Sociology, Winthrop University, Rock Hill, SC (U.S.A.)

Seasonality of children's residential mobility: A research note (p. 205-213)

Parents are often advised to schedule changes of residence for the summer so that children do not change schools during the regular school year. But very little research has been done on seasonality of children's moves and whether families that move 'off season' differ from those that move in the summer. The child supplement to the 1988 National Health Interview Survey offers an opportunity to examine the degree of seasonality of children's mobility and to analyze characteristics that increase or decrease the probability of moving during the summer months. We find that many variables included in studies of differential mobility exhibit seasonal effects, but in a multivariate model age of child (beyond 7 or 8 years old), long-distance moves, a highly educated mother, and race that is not Black most strongly raise the odds of moving in the summer. (UNITED STATES, RESIDENTIAL MOBILITY, CHILDREN, SEASONAL FLUCTUATIONS, MIGRATION DETERMINANTS)

96.88.14 - English - Glenn V. FUGUITT, Department of Rural Sociology, University of Wisconsin-Madison, Madison (U.S.A.), and Timothy B. HEATON, Department of Sociology, Brigham Young University, Provo, Utah (U.S.A.)

The impact of migration on the nonmetropolitan population age structure, 1960-1990 (p. 215-232)

In this paper we examine the short-run impact of migration on the age composition of nonmetropolitan areas. Changes in age structure can have important consequences at the local level, and the influence of migration is particularly notable because it is highly age-graded, with different migration patterns found in various types of nonmetropolitan communities. Here we compare the impact of migration on age structures in metropolitan and nonmetropolitan areas across the last three decades. Within nonmetropolitan areas we also compare counties with colleges, commuting counties, agricultural counties and retirement counties. We conclude that several factors influence the impact of migration on age structure. Impacts will be greater in smaller than in larger population groups, and in areas that specialize in economic functions that impinge on a particular age group. But in general, migration adds young people to metropolitan areas and older people to nonmetropolitan areas. Differential impacts may be lessened in periods, such as 1970-80, when substantial population redistribution was underway. Nevertheless, prior and present fertility and mortality trends, and the cumulative history of migration well exceed the impact of migration on age in any ten-year interval. (UNITED STATES, AGE DISTRIBUTION, MIGRATION)

96.88.15 - English - David A. SWANSON, Arkansas Institute for Economic Advancement, University of Arkansas at Littlle Rock, and NIMH Center for Rural Mental Healthcare Research, University of Arkansas for Medical Sciences, Little Rock, Arkansas (U.S.A.), and Jeff TAYMAN, San Diego Association of Governments, San Diego, CA (U.S.A.)

Between a rock and a hard place: The evaluation of demographic forecasts (p. 233-249)

Forecasting, in general, has been described as an unavoidable yet impossible task. This irony, which comprises the 'rock' and the 'hard place' in the title, creates a high level of cognitive dissonance, which, in turn, generates stress for those both making and using forecasts that have non-trivial impacts. Why? Because the forecasted numbers that are invariably accorded a high degree of precision inexorably reveal their inevitable imprecision when the numbers forming the actuality finally take place and the numbers comprising the forecast's errors are precisely measured. The current state of the art in demography for dealing with the 'rock' and the 'hard place' is a less-than-successful strategy because it is based on an acceptance of accuracy as the primary evaluation criterion, which is the source of cognitive dissonance. One way to reduce cognitive dissonance is to change the relationship of the very cognitive elements creating it. We argue that forecast evaluations currently focused on accuracy and based on measures like RMSE and MAPE be refocused to include utility and propose for this purpose the 'Proportionate Reduction in Error' (PRE) measure. We illustrate our proposal with examples and discuss its advantages. We conclude that including PRE as an evaluation criterion can reduce stress by reducing cognitive dissonance without, at the same time, either trivializing the evaluation process or substantively altering how forecasts are done and presented. (METHODOLOGY, PROJECTIONS, EVALUATION)

96.88.16 - English - Steve H. MURDOCK and Md Nazrul HOQUE, Department of Rural Sociology, Texas A & M University, College Station, TX (U.S.A.) The effect of undercount on accuracy of small-area population estimates: Implications for the use of administrative data for improving population enumeration (p. 251-271)

The effects of underenumeration on the accuracy of alternative methods of population estimation have not been sufficiently analyzed. Although the US Bureau of the Census has decided not to adjust either the counts or its estimates for underenumeration in 1990, the extent to which local population estimates may account for underenumeration is of importance both for those who may wish to adjust existing estimates and in anticipation of future census adjustments. This paper examines the accuracy of small-area population estimation methods with and without adjustment. Mean Percent Errors, Mean Absolute Percent Errors, and Mean Percent Absolute Differences between local estimates for 1990 and 1990 adjusted and unadjusted census counts are computed. Population estimates for 1990 made using housing unit, ratio correlation, and component methods are compared for 451 counties and 2,633 places in the states of California, Florida, Texas, and Wisconsin. An analysis of the data for counties shows little indication that local estimates more accurately estimate the adjusted than the unadjusted population counts. The results for places show clear improvements in accuracy for places in Florida and Texas. Implications of the findings for issues related to undercount adjustment and local population estimates are discussed. (UNITED STATES, POPULATION ESTIMATES, UNDERENUMERATION, LOCAL COMMUNITIES)

SEPTEMBER 1995 - VOLUME 14, NUMBER 3

Biosocial models of demographic behavior

96.88.17 - English - Bob WELLER, National Institutes of Health, Bethesda, MD (U.S.A.) Biosocial models of demographic behavior: An introduction (p. 277-282)

A workshop on biosocial models of demographic behavior was organized to provide information to members of the Social Sciences and Population Study Section (SSP), the group entrusted by the National Institutes of Health (NIH) with the responsibility for conducting the first level of peer review of demographic applications submitted to NIH for possible funding. Some of the variables studies by demographers are biological, e.g., fertility, fecundity, morbidity, and mortality, so demographers are not unaware of biological variables. However, they tend to treat biological variables as something to be explained by social, economic, and psychological factors rather than to be integrated into an explanatory paradigm. This workshop contains papers that focus upon various stages of the life cycle and explore the importance of biosocial variables in explaining selected aspects of human behavior. (METHODOLOGY, MODELS, BIOLOGY, SOCIOLOGY, BEHAVIOUR, DEMOGRAPHIC RESEARCH)

96.88.18 - English - David W. FULKER and Stacey S. CHERNY, Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado (U.S.A.)

Genetic and environmental influences on cognition during childhood (p. 283-300)

The basic methodology of behavior genetics is described in the context of the twin and sibling/adoption design. Results of applying this model to cross-sectional data on cognitive development throughout the lifespan are presented. Results from a large longitudinal twin and adoption study of general intelligence are presented to illustrate the use of the basic behavior genetic model in studying the causes of continuity and change in development. A special model is presented for the study of abnormal behavior occurring at the extremes of the distribution and an adaptation of the model is discussed for the study of genetic linkage or the mapping of quantitative trait loci (QTL). Results of applying this model to a sample of twins and kindred siblings indicated the presence of a major QTL for dyslexia on chromosome 6. The purpose of the paper is to illustrate the scope of behavior genetic methodology in studying individual differences in behavior in a biosocial context. (METHODOLOGY, GENETIC MODELS, BEHAVIOUR, TWINS, ADOPTION)

96.88.19 - English - David C. ROWE, University of Arizona, Tucson, Arizona (U.S.A.) Biosocial models of deviant behavior (p. 301-313)

This article describes biological influences on criminality. It presents illustrative data suggesting a biological sex difference in criminality and heritable differences in this trait among individuals. Next, methods of isolating environmental influences are described, including shared environmental effects, gene x environment interactions, and nonshared environmental effects. Using research designs that include just one level of genetic relatedness (e.g., full siblings) is scientifically a poor choice. Using environment-friendly behavior genetic research designs is both proper and would offer many avenues for environmental analysis. (METHODOLOGY, MODELS, BIOLOGY, SOCIOLOGY, GENETICS, DELINQUENCY, ENVIRONMENT)

96.88.20 - English - Kenneth M. WEISS, Penn State University, University Park, Pennsylvania (U.S.A.) Implications of genetic variation within and between human populations (p. 315-325)

Human variation is extensive both within and between populations. This variation affects all traits, including the susceptibility to disease and responses to the environment. For social and political reasons, we tend to think of our species or our own national population as being divided into meaningful groups variously called by such terms as 'races', or 'ethnic' groups, and there is often an implicit assumption that these groups are relatively homogeneous within and very different between. Examples are given to show that there are major differences in the frequency of genetic susceptibility to various diseases between some such groups, but that the amount of variation among individuals is extensive even within such groups. Population subdivision can be useful for studying disease, but human variation is a general phenomenon tied to groups via their population and geographic history, not value-based categorical differences. (POPULATION GENETICS, RACES, MORBIDITY)

96.88.21 - English - Toni P. MILES, Biobehavioral Health Program, and Center for Special Populations and Health, and Christine HIMES, Population Research Institute, The Pennsylvania State University, University Park, Pennsylvania (U.S.A.) Biological and social determinants of body size across the life span. A model for the integration of population genetics and demography (p. 327-346)

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. (BIOLOGY, DEMOGRAPHY, AGEING, OBESITY)

96.88.22 - English - J. Richard UDRY, Carolina Population Center, University of North Carolina at Chapel Hill, NC (U.S.A.) Policy and ethical implications of biosocial research (p. 347-357)

Social scientists are often concerned that research about the biological causes of behavior will encourage biologically-based public policy. Biosocial research models, jointly examining both social and biological causes of behavior, prevent simplistic biological thinking Public policy is concerned with bringing about social change. Biological models of behavior primarily explain individual differences, and are not useful for guiding policies directed toward producing social change. When we allow our social ethics to prevent us from asking certain research questions, we will produce politically correct research results. We fall into such strategies because we imagine that ethics can be deduced from the nature of the world. (BIOLOGY, SOCIOLOGY, POLITICS, ETHICS, RESEARCH)

96.88.23 - English - John B. CASTERLINE, Research Division, The Population Council, New York (U.S.A.) Biosocial models: Can demographers ignore them? (p. 359-371)

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 disciplinary boundaries; that is, the obstacles are institutional, not scientific. (BIOLOGY, SOCIOLOGY, MODELS, DEMOGRAPHIC RESEARCH)

Back to home page