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By restricting the number of age groups to two and by introducing continued fractions, the dynamics of populations with deterministically changing vital rates are completely specified at all times. Explicit expressions for the sequence of the product of population projection matrices are given. From these, relative age distribution and reproductive values to any desired accuracy are obtained as functions of the vital rates. Thus, the results given in this paper are stronger than any existing weak ergodic theorems. [ABSTRACT FROM AUTHOR]

In this paper we have shown that the statements made in our original paper and disputed by Sloane and Lee are not ". . . . .at least partially in error." Concerning the first two areas of disagreement, Sloane and Lee's analysis did not address the conclusions that we reached and, therefore, could not refute them. In the first instance the observations of Sloane and Lee are useful in understanding how one of the effects we observed occurred, but in the second area the usefulness of their analysis is not at all clear. The third area of disagreement resulted because Sloane and Lee paid insufficient attention to the observed sample relationships and used a statistical test that is inefficient for the type of data used. Of course, our disagreement is not with log-linear methodology, but with its inappropriate application and interpretation by Sloane and Lee. In two instances they used results from the log-linear procedures to address issues that could not be addressed by those particular results, and in another instance they used a log-linear test of statistical significance when a more efficient alternative provides a different picture. The problems associated with the Sloane and Lee analysis illustrate the importance of precise specification of the substantive issues being investigated and the careful interpretation of the substantive implications of the original data and statistical results.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

The central concept of microeconomic theories of fertility is opportunity cost--the product of wife's employment lost due to childbearing and the value of her employment. This paper presents a model for analyzing opportunity cost using panel data. The average loss of employment attributable to a second- or higher-order birth, calculated at around age 2, is over 400 hours per year. This time cost represents an income loss of about $1050 in 1969 dollars. Time cost is independent of such demographic factors as birth order and age of oldest sibling. Neither does time cost depend on husband's wage rate or wife's education or potential wage rate. This indicates that many microeconomic models of fertility have been seriously misspecified. The paper also compares results from static and dynamic models, explores possible problems due to simultaneity bias, investigates the relationship between changes in employment (including time cost) and initial employment level, and identifies the difficulties of theorizing about opportunity cost. [ABSTRACT FROM AUTHOR]

It is well known that the intrinsic rates of growth derived separately for the males and females in a population, when one assumes the continuation of their respective mortality and fertility experiences, usually turn out to be different. Noting that the phenomenon of human reproduction is a product of the cooperation between the two sexes, we have attempted in this paper to define the sex-age-specific fertility rates as a function not only of age but also of time, where the latter is implicitly introduced in the model through the sex composition of the reproductive population. It has been shown that a stable model can then be defined based on such changing sex-age-specific fertility rates and given sets of unchanging mortality rates. The fertility rates stabilize with time, and the common intrinsic rates of growth for the two sexes are found to lie in the interval generated by the corresponding rates of the two one-sex models. Several other interesting relationships among the parameters of this model have been presented in the paper. Among other alternatives, a least square solution has been presented for the values of sex-age-specific fertility rates that are minimally discrepant with the observed rates but are consistent in terms of the parametric estimates they generate. It is interesting to note that a relatively modest adjustment in the sex-age-specific fertility rates is all that it takes to eliminate the inconsistencies generated by the sepafate one-sex models. [ABSTRACT FROM AUTHOR]

The present paper deals with changes over time in the sex composition of a given population. Such changes are generated by the components of population change: natality, mortality, immigration and emigration. The objective of this paper is to propose a model which provides a quantitative statement concerning the effect of each such component on the change in the sex composition of the population. It is shown that the model is applicable to the measurement of sex composition by either the masculinity proportion of the sex ratio. To demonstrate the application of the proposed model, an example based on Canadian data is given. [ABSTRACT FROM AUTHOR]

Our recent paper in Demography (Gray, Stockard, and Stone 2006) has attracted the close scrutiny of several prominent academics. Three sets of formal comments, authored independently by Ermisch, Martin, and Wu (EMW), appear in this issue of Demography. In this response we argue that the analysis and evidence of our 2006 paper have withstood the scrutiny of EMW. In particular, we find that a substantial part of the rising share of nonmarital births since 1970 is due to a selection effect associated with marriage. This same selection effect also explains how birth rates could rise in both groups, even though their combined birth rate did not. In sum, though we appreciate the opportunity to expand on several key aspects of our 2006 article, we see no reason to substantially revise any of our major conclusions based on the EMW comments. [ABSTRACT FROM AUTHOR]

It is widely believed that structural variables such as inequitable land distribution, lack of rural employment opportunities, and rural-urban wage and amenity gaps influence population movements in developing countries. Yet quantitative evidence is scant. In this paper a multilevel model is used to investigate the effects of individual-, household-, and areal-level factors on rural-urban out-migration in the Ecuadorian Sierra. Data from a detailed survey carried out in 1977-1978 and from government macro-areal statistics are used to investigate factors affecting the out-migration of youths aged 12-25. Preliminary conclusions are presented on the usefulness of multilevel models in studying migration and policy implications for Ecuador. [ABSTRACT FROM AUTHOR]

The observed joint distribution of births and child deaths for a cohort of women at a given point in time depends on the number of children that would have been born had the family experienced no deaths, the number of child deaths experienced, and the proportion of these deaths that are replaced by a subsequent birth. In this paper we estimate the parameters of the assumed distributions of these three events using a minimum distance estimation model and data from the 1970 Brazilian census. The parameter estimates are shown to be similar to those obtained previously using a maximum likelihood estimation model. When the data are subdivided according to women's years of schooling, estimates of probability of a child death and mean and variance of children born if no deaths decrease while estimates of probability of replacement of a dead child increase as years of schooling increase. [ABSTRACT FROM AUTHOR]

In this paper we develop and test a theory of childhood mortality after the first month of life. Parents are assumed to have well-defined family size and sex composition objectives and to face severe budget constraints. In this set of circumstances, it is understandable that they will make allocative decisions that will affect the survival probabilities of children. These decisions and the environmental influences on mortality are the basic forces which determine whether a child will survive through the post-neonatal period. The model is tested with survey data from rural Uttar Pradesh, India. The results are consistent with the hypothetical framework discussed above. The burden of this pattern of choice is felt particularly strongly by female births. [ABSTRACT FROM AUTHOR]

This paper analyzes cross-cohort trends in the age pattern of women at first birth in the United States. The analysis involves fitting the Coale-McNeil marriage model to the age distribution of first birth frequencies for a number of recent white and nonwhite cohorts. Methodologically, the results (a) provide support for the application of the Coale-McNeil marriage model to first birth data, and (b) demonstrate the ability of the model to accurately project first birth fertility for cohorts which have yet to complete their childbearing years. Substantively the results indicate (a) that the proportion of women who will never have a first birth is increasing across cohorts and can be expected to be as high as .25 and .20 for recent white and nonwhite cohorts respectively; (b) that recent nonwhite cohorts have an appreciable number of first births at earlier ages than their white counterparts, as well as a lower mean age at first birth and increasingly less dispersion (across cohorts) in their age at first birth; and (c) that the mean age at first birth and the proportion of first births occurring between ages 25 and 34 is increasing across cohorts of white women but is stable across cohorts of nonwhite women. [ABSTRACT FROM AUTHOR]

This paper is part of a long-term investigation known as the Mormon Historical Demography Project. It examines the capability of a simulation model, originally proposed by John Bongaarts (1976), to fit the natural fertility pattern which characterized the mid-nineteenth century Mormon population. Application of this model permits estimates to be made of the historical timing and age-incidence of fertility limitation. A sensitivity analysis of the model's parameters demonstrates that simple changes in the model's proximate determinants of fertility, excluding contraceptive practices, would be insufficient to account for later transition effects. Thus the results successfully capture the dynamics underlying the Mormon natural fertility pattern as well as offer a framework for future modeling of the transition away from natural fertility. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical model for changing mortality in functional form. This model may be used to obtain cohort forces of mortality and cohort survivorship functions from a period force of mortality and a period life table under conditions of gradually changing mortality if an estimate of the amount of change in mortality is available. An example is given to show how the cohort functions are derived from the period functions. [ABSTRACT FROM AUTHOR]

This paper introduces an analytic framework that can be used to assess the relationships between individual movement differentials and place characteristics, on the one hand, and aggregate mobility levels and city-suburb population change (in size or composition), on the other. Application of this framework using census data for individual metropolitan areas allows the analyst to decompose population changes due to net migration into contributing mobility streams and their component rates which are subject to unique community and individual influences. The paper provides both theoretical and empirical rationale for the framework, illustrates its use with 1970 census data, and discusses its implications for empirical research on city-suburb population redistribution. [ABSTRACT FROM AUTHOR]

In this paper, the actuarial method of multiple decrement life table analysis of censored, longitudinal data is examined. The discussion is organized in terms of the first segment of usage of an intrauterine device. Weaknesses of the actuarial approach are pointed out, and an alternative approach, based on the classical model of competing risks, is proposed. Finally, the actuarial and the alternative method of analyzing censored data are compared, using data from the Taichung Medical Study on Intrauterine Devices. [ABSTRACT FROM AUTHOR]

A population consisting of women who have conceived before a time t ignores all women whose conception time exceeds t. Such a population is considered as a truncated population, and the samples are called truncated samples. Under the assumption that fecundability among women varies according to a Beta distribution (with parameters a and b), the distribution of conception times in a truncated population can be considered as truncated Type I geometric. This paper presents an algorithm to obtain the moment and maximum likelihood estimates of a and b from the truncated samples. Large sample properties of the estimators are also studied. Examples using the Hutterite and the Princeton Fertility Survey data are given. [ABSTRACT FROM AUTHOR]

This paper discusses the mathematical relationship between Schoen's ∇ and an index derived from log-linear models for making compositionally controlled comparisons of the occurrence of an event in a population. The merits of each and the contributions of the log-linear formulation are discussed. [ABSTRACT FROM AUTHOR]

This paper examines the probabilities of first marriage dissolution in Canada, using the marital history data collected from a national sample of women in their reproductive years. It is found that age at marriage, year of marriage, cohabitation before marriage, a premarital birth or conception, urban-rural place of residence, and religiosity are all significantly correlated with marriage dissolution. Religion and education, on the other hand, do not seem to affect the marriage dissolution probabilities when other factors are controlled. Canadian patterns are not too different from patterns in the United States. [ABSTRACT FROM AUTHOR]

When populations get destabilized, the birth rates derived using stable population theory need adjustments. The most recent adjustment suggested by Coale, which is based on the proportion under 15 for both sexes and l5 is found to be very robust. In this paper an alternative adjustment to stable birth rate estimates using the framework of the generalized stable population equations is derived, and the close agreement between the new adjustment and that given by Coale is illustrated for some African countries. A simpler, more robust estimate of birth rate is also deduced from Coale's adjusted birth rate. [ABSTRACT FROM AUTHOR]

This paper examines relationships among six social factors and infant mortality in California in 1978 and seeks to explain social differentials in terms of two intervening variables. Linked birth and infant death records are analyzed to test for interactions among the social factors and mortality and for causal linkages involving the intervening variables. Social factors are related to the risk of infant mortality in a conditional manner; significant interactions involve maternal age and both birth order and marital status, and race/ethnicity and both education and marital status. Birth weight and prenatal care are important intervening variables but do not fully explain the social differentials. [ABSTRACT FROM AUTHOR]

This paper develops and estimates an interactive contextual model of migration in Ilocos Norte, the Philippines. It focuses on how contextual features alter the effects of family class status and community development level on the family's migration decisions. The model estimates show a curvilinear relation between class status and migration, but the pattern differs in accordance with the prevalence of migration from the community in the past. In addition, the effects of socioeconomic development and agricultural commercialization patterns vary with context. These results demonstrate the importance of using interactive models for analyzing the contextual influences on migration. [ABSTRACT FROM AUTHOR]

This paper, analyzes movements among household types. Persons in one household may join another type. Correspondingly, a household's structure may change when someone joins it. Data are from the Panel Survey of Income Dynamics, spanning `1968-1980. The individuals followed in the survey generated spells analyzed with a multivariate competing risk hazard model. We develop a map of the flow among household types and of the economic and demographic profiles of individuals making the transitions. We find wide variability in the stability of household types and marked racial differences in the relative stability and pattern of destination choices. [ABSTRACT FROM AUTHOR]

Survival analysis can be used to study the association between a set of explanatory variables and the age at which an event of interest, say weaning, occurs. As retrospectively reported age data often contain serious reporting errors, many analysts prefer to use current status data. In this paper, the authors discuss two approaches to fitting survival models to current status data from the Pakistan Fertility Survey. A generalized linear model approach, using constrained maximum likelihood estimates, proves computationally expensive, so a transformation of the baseline hazard is modeled, using spline function. [ABSTRACT FROM AUTHOR]

This paper compares several methods of generating confidence intervals for forecasts of population size. Two rest on a demographic model for age-structured populations with stochastic fluctuations in vital rates. Two rest on empirical analyses of past forecasts of population sizes of Sweden at five-year intervals from 1780 to 1980 inclusive. Confidence intervals produced by the different methods vary substantially. The relative sizes differ in the various historical periods. The narrowest intervals offer a lower bound on uncertainty about the future. Procedures for estimating a range of confidence intervals are tentatively recommended. A major lesson is that finitely many observations of the past and incomplete theoretical understanding of the present and future can justify at best a range of confidence intervals for population projections. Uncertainty attaches not only to the point forecasts of future population, but also to the estimates of those forecasts' uncertainty. [ABSTRACT FROM AUTHOR]

In this paper, we model unmarried teenagers' decisions about their pregnancy outcome by considering that the teenager contrasts her expected utility (1) as a married mother, (2) as an unmarried mother, or (3) after abortion. We use cross-sectional data on 297 California teenagers aged 13-19 who were pregnant for the first time between 1972 and 1974. Both Anglo and Mexican-American girls are included. We find that pregnant girls who are eligible for or are receiving public assistance are more likely to give birth and remain unmarried. Teenagers with greater time values are more likely to choose abortion, and Mexican-American girls are more likely to carry their pregnancies to term. [ABSTRACT FROM AUTHOR]

This paper examines biases that may occur when models of couple behavior are estimated using one partner's report of own and of spouse's desired family size rather than independent reports obtained from both partners. When estimates of random measurement error are incorporated in a model of couple fertility expectations, proxy reports are valid indicators of spouse desires. In particular, there is little evidence that proxy reports are affected by systematic errors arising from projection of own beliefs onto the spouse. For desired family size, random measurement error in both proxy and self reports is of far greater concern than is systematic error. [ABSTRACT FROM AUTHOR]

This paper presents estimates of delayed childbearing and permanent childlessness in the United States and the determinants of those phenomena. The estimates are derived by fitting the Coale-McNeil marriage model to survey data on age at first birth and by letting the parameters of the model depend on covariates. Substantively, the results provide evidence that the low first birth fertility rates experienced in the 1970s were due to both delayed childbearing and to increasing levels of permanent childlessness. The results also indicate that (a) delayed childbearing is less prevalent among black women than among nonblack women; (b) education is an important determinant of delayed childbearing whose influence on this phenomenon seems to be increasing across cohorts; (c) education is positively associated with heterogeneity among women in their age at first birth; (d) the dispersion of age at first birth is increasing across cohorts; (e) race has an insignificant effect on childlessness; and (f) education is positively associated with childlessness, with the effect of education increasing and reaching strikingly high levels for the most recent cohorts. [ABSTRACT FROM AUTHOR]

Age-specific population growth rates were introduced to demographic analysis in earlier work by Bennett and Horiuchi (1981) and Preston and Coale (1982). In this paper, we derive a method which uses these growth rates to transform what may be a set of incompletely recorded deaths by age into a life table that accurately reflects the true mortality experience of the population under study. The method does not rely on the assumption of stability and, for example, in contrast to intercensal cohort survival techniques, is simple to implement when presented with nontraditional intercensal interval lengths. Thus we can obtain mortality estimates for less developed countries with defective data, despite departures from stability. Further, we assess the sensitivity of the method to violations in various assumptions underlying the procedure: error in estimated growth rates, existence of non-zero net intercensal migration, age dependence in the completeness of death registration, and misreporting of age at death and age in the population. We demonstrate the use of the method in an application to data referring to Argentine females during the period 1960 to 1970. [ABSTRACT FROM AUTHOR]

Most research on married women's labor force participation relates characteristics of individual women to their probability of labor force participation. Some studies relate characteristics of geographic areas to average labor force participation rates in those areas, although these aggregate level analyses are usually gross tests of ideas about individual-level processes. Here we take a quintessentially sociological perspective and seek to understand how characteristics of geographic areas structure the relationship between properties of individual women and their probabilities of labor force participation. Our analysis has two steps. In step one, we fit individual-level probit models of married women's probability of labor force participation. A separate model is fitted in each of 409 areas using 1970 Census data, and the relationship between individual characteristics and labor force participation is found to vary substantially across areas. In step two, we attempt to explain areal variation in the effects of women's children on their labor force participation. We hypothesize that the effect of children on their mothers' labor force participation is a function of the cost and availability of childcare , and of the "convenience" of jobs for working mothers in the places where the mothers live. Measures of childcare cost, childcare availability and job convenience are developed. Weighted least squares analyses of probit coefficients from the first stage are, in general, very consistent with our findings, and suggest that the approach taken in this paper is likely to be a fruitful one for future studies. [ABSTRACT FROM AUTHOR]

The purpose of this paper is twofold: (a) to provide a complete self-contained exposition of estimating life tables with covariates through the use of hazards models, and (b) to illustrate this technique with a substantive analysis of child mortality in Sri Lanka, thereby demonstrating that World Fertility Survey data are a valuable source for the study of child mortality. We show that life tables with covariates can be easily estimated with standard computer packages designed for analysis of contingency tables. The substantive analysis confirms and supplements an earlier study of infant and child mortality in Sri Lanka by Meegama. Those factors found to be strongly associated with mortality are mother's and father's education, time period of birth, urban/rural/estate residence, ethnicity, sex, birth order, age of the mother at the birth, and type of toilet facility. [ABSTRACT FROM AUTHOR]

This paper introduces an empirical indicator designed to measure the temporal stability of regression models used to produce subnational population estimates. Analusis of 67 counties in Florida centers on 1970 total population estimates generated from ratio-correlation and difference-correlation models. Comparisons are made between eight different regression specifications and employ a quantitative measure of relative estimate accuracy. The major findings of this study are that (a) variable measurement and type are important determinants of estimate accuracy, and (b) although temporal stability of the coefficients impacts estimation errors, the influence is not as pervasive as is suggested in the literature. [ABSTRACT FROM AUTHOR]

Analyzing data from a fifteen-year follow-up survey of high school students originally surveyed in 1957-58 and resurveyed in 1973-74, this paper examines the effects of the timing of marriage and first birth on subsequent childspacing, holding constant the effects of other variables that may be sources of spuriousness. The results suggest that age at first marriage has a causal effect on the occurrence of a short first birth interval and that age at first marriage and premarital pregnancy interact in their effect on the occurrence of a short second birth interval. Age at first marriage has no causal effect on the spacing of the second birth for those whose first child was maritally conceived. The spacing of the first birth, however, appears to have a causal effect on the spacing of the second. [ABSTRACT FROM AUTHOR]

This paper examines the utility of viewing migration in the context of work careers and family life cycles. We do this by studying migration as a discrete state, continuous time process. We find that the inverse relationship between age and migration is due almost completely to the effects of family life cycle and work career variables. Further, we find that job- or location-specific resources, prestige and wage deter migration. [ABSTRACT FROM AUTHOR]

The "two-sex problem" is one of attempting to preserve the essential character of male and female rates of marriage (or birth), since the expression of those rates is influenced both by the age-sex composition of the population and the underlying age-sex schedule of preferences. The present paper focuses on marriage and advances a theoretically based, realistic, and conceptually simple solution. In the continuous case, where exact male and female ages are used, equation (11) provides a mathematical relationship which equates the sum of the male and female marriage propensities of the observed population with that of the model. When discrete age intervals are used, the two-sex consistency condition is given by equation (14) which equates observed and model population rates calculated using the harmonic means of the number of persons in the relevant male and female age groups. The harmonic mean consistency condition is shown to be fully sensitive to the competitive nature of the "marriage market." When compared with alternative approaches to the two-sex problem in the context of data for Sweden, 1961-64, the simple harmonic mean method yields results fairly similar to those of the other methods. None of the two-sex methods do particularly well at predicting the actual distribution of marriages, however. The likely reason is that the underlying marriage preferences changed, a circumstance which emphasizes the importance of carefully conceptualizing how observed behavior can be decomposed into the effects produced by age-sex composition and those produced by the underlying preferences. [ABSTRACT FROM AUTHOR]

The proportional hazards life table is a recently developed approach to the analysis of survival data when mortality risks vary among individuals. It assumes that at a given age (or duration since the start of a life) the force of mortality is a constant (specific to that age) multiplied by a proportionality factor which is determined by the characteristics of the individual and does not change unless these covariates do. In this paper, the method is reviewed for the case where the covariates are fixed at the start of the lifetime and illustrated by an application to marital dissolution in the United States. [ABSTRACT FROM AUTHOR]

This paper reports a mildly restricted procedure for using a theoretical causal ordering and principles from path analysis to provide a basis for modifying regression coefficients in order to improve the estimation accuracy of the ratio-correlation method of population estimation. The modification is intended to take into account temporal changes in the structure of variable relationships, a major element in determining the accuracy of post-censal estimate. The modification of coefficients is conservative in that is uses rank-ordering as a basis of change. Empirical results are reported for counties in Washington state that demonstrate the increased accuracy obtained using the proposed procedure. [ABSTRACT FROM AUTHOR]

This paper uses married couples' anticipated consequences of having a (another) child to predict their reproductive intentions. Parity-specific models identify different variables as predictors of reproductive behavior at different parities but do not yield interpretable patterns of difference by parity. Parity-specific models are not significantly stronger predictors of reproductive behavior. Generally, wife-only models are distinctly superior to husband-only models. Two-sex models are usually better predictors than one-sex models but not enough better to justify the additional cost. [ABSTRACT FROM AUTHOR]

A study is made of the effects of associated causes of death, and of dependency among causes of death, by observing the relative importance of one cause of death when another is eliminated under various competing risk models. Two disease pairs, cancer and infectious disease and stroke and ischemic heart disease, are selected for analysis because they represent different types of disease dependence. Crude probabilities of death for each disease are calculated for the U.S. white male population in 1969. Next, the effects of the complementary disease in a pair are hypothetically eliminated in one of three ways: (a) a standard competing risk adjustment for cause elimination when deaths are singly caused (Chiang, 1968), (b) lethal defect-pattern of failure computations for multiply caused death when no causal order is inferred (Manton et al., 1976), and (c) relative susceptibility, computations for multiply caused deaths when causes are ordered (Wong, 1977). The paper closes with a discussion of the relative merits of the three types of adjustments. [ABSTRACT FROM AUTHOR]

It is generally accepted that socioeconomic differentials in fertility are minimal among urban couples with nonfarm origins -- two generation urbanites. In this paper, we replicate Duncan's (1965) analysis to see if the two generation urbanite hypothesis holds for more recent cohorts of American women. In four cohorts of women, drawn from three recent fertility surveys, we find no support for the two generation urbanite hypothesis. It appears that the links between farm background, socioeconomic status and fertility were different for the low fertility cohorts of women born in the early 1900's and the more recent cohorts of women who experienced the baby boom. [ABSTRACT FROM AUTHOR]

Seasonal patterns in conception rates have been documented in several recent studies. In this paper, a mathematical model of the reproductive process is developed through which the impact of such variation in conception rates is assessed. It is found that the effect on fertility can be quite substantial, but that the birth rate when seasonal variation is occurring is approximated well by the birth rate calculated when conception rates are constant at their mean. These results indicate that further documentation of seasonality in conception rates and exploration of the causes of these patterns and their change is an important area for demographic research. [ABSTRACT FROM AUTHOR]

To influence the number of children ever born to a woman, socioeconomic variables must operate through behavioral and biological mechanisms such as the age at marriage, the level of fertility in the absence of deliberate fertility control, and the level of control exerted to reduce fertility within marriage. In this paper, we propose a new measure of cumulative fertility which is standardized for the age-fecundity relationship and for exposure to the risk of conception associated with duration of marriage. A simple model of fertility behavior which incorporates some of the mechanisms through which socioeconomic factors may affect fertility is developed and applied to data from the United States to demonstrate the properties of alternative measures of family size. The results indicate that use of the new measure allows more precise estimates of socioeconomic fertility relationships than would be obtained with children ever born or by sample stratification. [ABSTRACT FROM AUTHOR]

A previous residential mobility model (Speare, 1974) assumes an additive relationship between residential satisfaction, desire to move, and mobility. This paper elaborates the model and applies it to intercounty migration. An interaction between community satisfaction and expectations to migrate is hypothesized which distinguishes four groups of decision makers. A survey in Durham, North Carolina and a unique mobility follow-up over eight years provide the data to test the model and the interaction. Furthermore, using various time periods for identifying migrants offers some methodological insights. Results support Speare's general formulation but only after the interaction is taken into account. A three-year migration interval is found to be appropriate. [ABSTRACT FROM AUTHOR]

The interval between marriage and the first conception leading to a live birth plays an important role in the determination of fertility components. Several probability models (Potter and Parker, 1964; Singh, 1961, 1964, 1967) based on varying sets of assumptions relating to this interval have been propounded in the recent past. All of them are based on the assumption that the females under study are susceptible to conception at the time of marriage. However, in certain situations, where some of the females already pregnant at the time of marriage report to have conceived within a short interval following marriage, this condition is not satisfied and these models become unsuitable. A probability distribution which is an inflated form of the continuous model proposed by Singh, for the time of the first conception leading to a live birth, is presented in this paper. It describes reasonably well the data on first conception times in the context of premarital conceptions. Simple expressions for the maximum likelihood estimators of the parameters involved in the model are obtained and a method for finding the asymptotic covariance matrix of the estimators is outlined. The model is applied to four sets of data. [ABSTRACT FROM AUTHOR]

Because of bias of unknown sign and extent introduced by age misreporting when calculating the singulate mean age of marriage in the usual manner, Van de Walle has suggested a fairly robust estimator based on stable population structure. Unfortunately not much is known about the properties of this estimator. Various demographers have argued informally that it indeed estimates the SMAM; others feel that it instead estimates the mean age of marriage in a cohort, the mean age of marriage in the stable population, or the singulate median age of marriage. In this paper the properties of this estimator are examined. Further, extensions of the Van de Walle estimator based on regression are shown to be significantly superior to the estimator alone. [ABSTRACT FROM AUTHOR]

Several authors have argued that increased work opportunities for women have helped to produce a reduction in the average age at marriage in the United States. This paper tests this proposition on data for the 100 largest SMSA's in 1960. Using ordinary least-squares regression, we find that areas of relatively attractive female employment opportunities had relatively low proportions of women ever married in the age interval 22-24. Other variables significantly related to the proportion married in an SMSA are its sex ratio, percent Catholic, and number of inhabitants. A decline in the sex ratio and improvements in female employment opportunities appear to have been equally influential in producing declines in proportions married between 1960 and 1970. [ABSTRACT FROM AUTHOR]

In this article, I make the case for using an integrative approach to health, broadly defined as social, emotional, mental, and physical well-being; for studying health among the young as an important marker for future health and well-being across the life course; and for understanding health disparities among the young as both causes and consequences of social stratification. An integrative approach bridges biomedical sciences with social and behavioral sciences by understanding the linkages between social, behavioral, psychological, and biological factors in health. It is furthermore vital that integration occur in all steps of the research process: in theory, design, data collection, and analysis. I use the National Longitudinal Study of Adolescent Health, or Add Health, as an example of an integrative approach to health and of the importance of adolescence and the transition to adulthood years for setting health trajectories into adulthood. Evidence is also presented on the linkages between health trajectories during adolescence and the transition to adulthood and social stratification in adulthood. [ABSTRACT FROM AUTHOR]

I estimate the frequencies of interracial kin relations, an important indicator of the isolation of racial groups in the United States. I use two techniques to estimate the size and heterogeneity of extended families. First, I develop a simple model that takes account only of kinship network sizes and intermarriage levels by race. This model allows a crude estimation of the frequency of multiracial kinship networks. Second, I produce more precise empirical estimates using a new hot-deck imputation method for synthesizing kinship networks from household-level survey data (the June 1990 Current Population Survey and the 1994 General Social Survey). One in seven whites, one in three blacks, four in five Asians, and more than 19 in 20 American Indians are closely related to someone of a different racial group. Despite an intermarriage rate of about 1%, about 20% of Americans count someone from a different racial group among their kin. [ABSTRACT FROM AUTHOR]

The ability of classical stable population theory to determine the equilibrium growth rate and age structure of a population from its vital rates in a single period depends on assuming that the observed maternity rates are equilibrium rates. This paper resolves the two-sex problem by replacing the fixed, age-specific fertility schedule of classical stable population theory by two basic relationships: a "birth matrix" and a "mating rule." Placing certain restrictions on the birth matrix and the mating rule (BMMR), I establish that under certain plausible conditions, the BMMR model solves the two-sex problem by allowing matings and births to adjust to changes in population structure. The BMMR model thus provides an equilibrating mechanism in place of a fixed maternity schedule of classical stable population theory. [ABSTRACT FROM AUTHOR]

Building upon an idea presented by Espenshade, Bouvier and Arthur (1982) about the eventual stationarity of a population subjected to a net reproduction rate of less than one and a constant stream of immigration, this note reports the consequences upon the birth trajectory for all possible values of the net reproduction rate. It has been shown that when the net reproduction rate is equal to one, the number of births increases linearly with time. As may be expected, the increase is exponential for values of net reproduction rate greater than one. [ABSTRACT FROM AUTHOR]

Multivariate analysis of the 1974 Malaysian Fertility and Family Survey tests the hypothesis that an inverse relationship between women's work and fertility occurs only when there are serious conflicts between working and caring for children. The results are only partly consistent with the hypothesis and suggest that normative conflicts between working and mothering affect the employment-fertility relationship in Malaysia more than spacio-temporal conflicts do. The lack of consistent evidence for the hypothesis, as well as some conceptual problems, lead us to propose an alternative framework for understanding variation in the employment-fertility relationship, both in Malaysia and elsewhere. This framework incorporates ideas from the role incompatibility hypothesis but views the employment-fertility relationship as dependent not just on role conflicts but more generally on the structure of the household's socioeconomic opportunities. [ABSTRACT FROM AUTHOR]

A simplified model is presented for the measurement of inter-live birth interval distributions. Comparative analyses of "effective fecund- ability," the mean length and variation of postpartum infecundity, and the parity progression ratio based on this measurement model are presented using data from U.S. marriage cohorts and from an Indian sample. Parity differentials in these reproduction parameters are investigated, and the ramifications for fertility estimate and projection discussed. [ABSTRACT FROM AUTHOR]