American fertility in transition: New estimates of birth rates in the United States, 1900–1910

This article presents new estimates of age-specific overall and marital fertility rates for the entire United States for the period 1900-1910. The estimation techniques are the two-census parity increment method and the own-children method. The data sources are the 1900 census public use sample and tabulations of 1910 census fertility data published with the 1940 census. Estimates are made for the total population, whites, native-born whites, foreign-born whites, and blacks. Low age-specific marital fertility at younger ages is consistent with a view of a distinctive American fertility pattern at this time.     

Combining forward and backward mortality estimation

Demographers often form estimates by combining information from two data sources—a challenging problem when one or both data sources are incomplete. A classic example entails the construction of death probabilities, which requires death counts for the subpopulations under study and corresponding base population estimates. Approaches typically entail ‘back projection', as in Wrigley and Schofield's seminal analysis of historical English data, or ‘inverse’ or ‘forward projection’ as used by Lee in his important reanalysis of that work, both published in the 1980s. Our paper shows how forward and backward approaches can be optimally combined, using a generalized method of moments (GMM) framework. We apply the method to the estimation of death probabilities for relatively small subpopulations within the United States (men born 1930–39 by state of birth by birth cohort by race), combining data from vital statistics records and census samples.     

Census-derived estimates of fertility by duration since first marriage in the Republic of Korea

This paper estimates ever-married birth rates by age and duration since first marriage and ever-married total fertility rates for the Republic of Korea, derived by applying an extension of the own-children method of fertility estimation to the 1975 and 1980 censuses. Since each census provides annual estimates for the 15-year period previous to enumeration, there is a ten-year period of overlapping estimates that facilitates checks for consistency and accuracy. Comparisons are also made with estimates derived from the 1974 Korea National Fertility Survey, which was part of the World Fertility Survey. The method works well, except in its application to the 1975 Census where the evidence suggests considerable misreporting of age at first marriage because of the way the question was asked and coded. Results confirm that ever-married fertility fell substantially in Korea between 1961 and 1980, with a temporary resurgence in the late 1960s and early 1970s. Ever-married fertility rose at younger ages and shorter durations and fell at older ages and longer durations. Ever-married fertility differentials by urban-rural residence and by education were usually in the expected direction, with urban fertility generally lower than rural fertility and the fertility of those with more education usually lower than the fertility of those with less education. Differential ever-married fertility by urban-rural residence and education declined over the estimation period.     

An assessment of the own-children method of estimating fertility by birthplace in Australia

This paper examines the validity of the own-children method of fertility estimates derived from the 1991 Census by a detailed investigation of mortality assumptions, the presence of non-own children, age misreporting and undercount. A comparison of fertility measures derived alternatively from the census using the own-children method and from vital statistics for the period 1987–91 indicates remarkably similar rates for Australia-born women, and plausible results for long established migrant groups. The own-children fertility levels for some recently arrived migrant groups, however, were found to be misleading. It is suggested that the own-children method is useful for the study of differential current fertility in Australia. Revised version of an essay awarded the W.D. Borrie Prize (graduate section), 1997, and presented to the session: Advances in methods for the analysis of demographic data of the 23rd General Conference of the International Union for the Scientific Study of Population, 11–17 October, Beijing. This paper is based on the author’s PhD thesis entitled:Fertility patterns of Australian selected immigrant groups, 1977–91.     

Combining registration-system and survey data to estimate birth probabilities

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

Gender bias in reproductive behaviour in Georgia,Indonesia, and Vietnam: An application of the own-children method

I present a method for estimating indicators of gender bias in reproductive behaviour, using microdata based on the own-children method. The method is first tested on a large sample from India with both birth history and household records. I then apply the method to Georgia, Indonesia, and Vietnam. My estimates demonstrate that the proportion of Georgian couples expressing a preference for sons in their fertility behaviour closely corresponds to the proportion resorting to sex selection at high parities. I show how individual Indonesian provinces provide examples of both son and daughter preference. The method also allows me to date the onset of sex imbalances at birth in Vietnam. The approach based on the own-children method therefore provides a unique tool for estimating the diversity and intensity of gender bias in reproductive behaviour.     

Aboriginal fertility: Trends and prospects

Estimates of Aboriginal fertility compiled from an analysis of 1981 and 1986 Census data on children ever borne by Aboriginal women reveal age-specific fertility rates slightly higher than those of other Australian women at ages above 25, but very much higher rates for younger women. The result is a total fertility ratio more than 50 per cent higher than in the total Australian population, with no more than slight variation between States and Territories. A differential analysis using standardized indices shows considerable differences in levels of fertility of categories of young Aboriginal women classified by education, labour force status and income, and also differences between urban and rural areas. Analysis of prospects for Aboriginal fertility levels confirms the likelihood of continuation in the downward drift in levels of fertility that has been established during the past decade. Comparison of the estimates with another recent set of estimates obtained using the own-children method shows broad conformity in levels of total fertility ratios over time, except in the most recent period, the mid-1980s. Nevertheless, the own-children estimates distort the recent trend and also the age distribution of Aboriginal fertility.     

White and nonwhite trends in first birth timing: Comparisons using vital registration and current population surveys

The magnitude of racial differences in first birth timing vary greatly depending upon the data sources from which they are estimated. Vital registration data (Heuser 1976; with updates from the National Center for Health Statistics 1974–1990) show that in recent years nonwhites have higher risks of a first birth at virtually all ages compared to whites. As a result very large and historically novel differentials in childlessness are forecast using these data (see Rindfuss et al. 1988; Chen & Morgan 1991; Morgan & Chen 1992). However, retrospective fertility history data collected from the 1980, 1985 and 1990 Current Population Surveys (CPS) suggest much smaller racial differences in completed childlessness and isolate racial differences in probabilities of first births at young ages. Differences also exist between theses two series for whites prior to the mid-1960s but not afterwards. Reasons for these differing estimates are suggested and examined. We conclude that a substantial portion of the differences result from an accumulation of biases in the vital registration estimates that affect primarily estimates of first birth timing. Thus, the CPS data provide a more firm basis for racial comparisons of first birth timing.     

Sampling variability of own-children fertility estimates

This paper develops methodology for estimating standard errors and confidence intervals for own-children estimates of age-specific birth rates and total fertility rates. The methodology applies to systematic samples of households, which are treated as simple random samples of women. The assumption of simple random selection, together with the treatment of sample subgroup size and reverse-survival ratios as constants instead of random variables, imply that sampling variability is slightly underestimated. The methodology is applied illustratively to fertility estimates based on the 1970 census of the Philippines.     

Multidimensional Life Table Estimation of the Total Fertility Rate and Its Components

Using discrete-time survival models of parity progression and illustrative data from the Philippines, this article develops a multivariate multidimensional life table of nuptiality and fertility, the dimensions of which are age, parity, and duration in parity. The measures calculated from this life table include total fertility rate (TRF), total marital fertility rate (TMFR), parity progression ratios (PPR), age-specific fertility rates, mean and median ages at first marriage, mean and median closed birth intervals, and mean and median ages at childbearing by child’s birth order and for all birth orders combined. These measures are referred to collectively as “TFR and its components.” Because the multidimensional life table is multivariate, all measures derived from it are also multivariate in the sense that they can be tabulated by categories or selected values of one socioeconomic variable while controlling for other socioeconomic variables. The methodology is applied to birth history data, in the form of actual birth histories from a fertility survey or reconstructed birth histories derived from a census or household survey. The methodology yields period estimates as well as cohort estimates of the aforementioned measures.     

Age at last birth and its components

This paper examines the ways in which the behavior of twentieth century cohorts of American women changed simultaneously in the three components of fertility that determine age at last birth--age at first birth, spacing between subsequent births, and parity progression ratios of subsequent births--to produce changes in the timing of the completion of childbearing. It decomposes changes in the mean age at last birth among cohorts and between whites and nonwhites to changes in these three components. To perform these analyses, we developed and applied a method to estimate the distributions and means of ages and last births, birth intervals, and parity progression ratios from age- and parity-specific fertility rates available from vital statistics data. Results show that the cohorts increased and decreased their age at first birth, birth intervals, and parity progression ratios of lower and higher birth orders in almost every possible combination so as to achieve a relatively young age at final birth.     

The number of illegal migrants of Mexican origin in the United States: Sex ratio-based estimates for 1980

This article reports the results of applying a sex ratio-based method to estimate the number of undocumented Mexicans residing in the United States in 1980. The approach centers on a comparison between the hypothetical sex ratio one would expect to find in Mexico in the absence of emigration to the United States and the sex ratio that is in fact reported in preliminary results from the 1980 Mexican Census. The procedure involves, inter alia, assuming a range of values for the sex ratio at birth and for census coverage differentials by sex in Mexico. Even the combinations of these values most likely to result in large estimates suggest that no more than 4 million illegal migrants of Mexican origin were residing in the United States in 1980.     

What’s happening to the age at first birth in the United States? A study of recent cohorts

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.     

Models for the estimation of the probability of dying between birth and exact ages of early childhood

Abstract This paper develops two models, each of which is designed to estimate the probability of surviving from birth to selected exact ages of early childhood: namely ages two, three and five. The models are designed for use in areas with deficient registration systems. They require, as input, statistics which can be derived from retrospective data supplied by census or survey respondents. The first model, the age model, converts statistics on the proportion dead of children ever born to women in age groups 20-24, 25-29 and 30-34 into estimates of q2, q3 and q5. The second model, the marriage model, converts statistics on the proportion dead of children ever born to women of five-year marriage duration intervals into these estimates. The models can be used independently or simultaneously. These models were developed from data generated by a large number of empirical fertility and mortality schedules. Regression analysis was used to determine the parameter values of the relationships specified, and several sets of equations for estimating values of qa, for a = 2, 3 and 5 comprise the final product of the paper. It should be noted that the conceptual basis for the models was first derived by William Brass. The data generated for the regression analysis provided an opportunity to test the original Brass estimated model. We are able to report that the model performed well over the wide range of fertility and mortality conditions included in the test.     

A qualitative study of the impact of adverse birth experiences on fathers

BackgroundBeing present during labour and birth can, for some fathers, result in feelings of fear, uncertainty, anxiety, and helplessness. Witnessing birth complications or adverse events may cause immediate and long-term anxiety and stress. In turn, this experience can impact on men’s sense of self and identity as a man and father and can affect his relationship with his infant and partner. The aim of this study was to explore the immediate and longer-term impact of witnessing a complicated or adverse birth experiences on men in heterosexual relationships and their role as a father.MethodsAn interpretive qualitative approach informed the design of this study. A total of 17 fathers, one from New Zealand and sixteen from Australia participated through face to face, telephone and email interviews. The ages of the men were between 24 to 48 years, and the time since the adverse birth experience ranged from 4.5 months to 20.5 years.FindingsThematic analysis revealed three major themes representing men’s experiences of witnessing a complicated birth or adverse event; ‘Worst experience of my life’, ‘Negotiating my place: communicating with health professionals’ and ‘Growing stronger or falling apart’. Men were unprepared and feared for the lives of their infants and partners, they expected and wanted to be involved in the birth and the maternity care journey, instead they were pushed to the side and excluded from the labour and birth during times of emergency. Being excluded from part or all of the birth perpetuated worry and vulnerability as, at times, men were left not knowing anything about what was happening to their partners. Midwives and other health professionals’ support was important to the way fathers adjusted and processed the complications of the labour and birth event. This experience impacted on their own mental health and their relationship with their baby and partner.ConclusionFindings demonstrate that following a complicated or adverse birth experience, men questioned their role as a father, their place in the family and their role at the birth. There is a need to include and inform the expectant father that help is available if they experience negative feelings of hopelessness or despair. Maternity services and care providers need to involve fathers so that they feel part of the maternity care system and journey which may mitigate feelings of helplessness.     

Estimation of vital rates by means of monte carlo simulation

Monte Carlo simulation has been used to estimate age-specific fertility and mortality rates for a small population,the French-derived isolate of Northside on St. Thomas, U. S. Virgin Islands. Estimates were based on data collected in a household census and genealogical survey and on birth, death, and marriage records for the years 1916to 1966. During this 50-year period (in which the population size increased from 202 to 657), the numbers of births and deaths were too, small to estimate age-specific rates directly, and in addition, death registration was incomplete. Mortality rates were estimated using a simulation program in which mortality was the only stochastic variable. A model mortality schedule was chosen which most accurately reproduced the growth pattern of the population over the 50-year period. To estimate fertility rates, a more complex simulation model was used in which fertility, nuptiality, and mortality were random variables with probability distributions. Preliminary estimates of fertility were made from the birth records and used as input to this simulation program. Birth probabilities were adjusted empirically from one set of simulation runs to the next, until population growth rates, as well as other demographic characteristics, were similar in the real and simulated populations. The birth rates which produced the best fit to the real population data were taken as the estimated age-specific fertility schedule. To reproduce the real population age structure more closely, secular changes in birth probabilities were applied.     

Estimating birth stopping and spacing behavior

A decomposition of age-specific marital fertility rates into indices related to spacing and stopping is developed by using Coale and Trussell's indices and the first few parity progression ratios. This approach leads to estimates of the mean birth interval among low-parity births that can be used to address the issue of fertility control early in marriage. In this way the model addresses several of the most serious limitations of Coale and Trussell's approach. The usefulness of the proposed indices is demonstrated by applications to historical data from the United States and Europe.     

Translation Formulae for Non-repeatable Events

China's one-per-hundred population survey, conducted in mid-1987, provides the first nation-level data with which to study recent fertility change in China. Using a recently developed extension of the ‘own-children’ method of fertility estimation, period parity progression ratios are computed from the survey data. Comparison with similar statistics computed from the 1982 one-per-thousand fertility survey provides a rigorous check on the quality of the results. The level of fertility so measured rose by 13 per cent between 1985 and 1987, compared with an increase of eight per cent in conventional total fertility ratios. Nearly 90 per cent of the increase was due to rising levels of progression from first to second birth. There can be little doubt that this, in turn, was due to a relaxation in the one-child family policy. Overall levels of progression to births of higher orders have been declining since 1982, but the evidence suggests that this is so only because of stringent government efforts to control births of third and higher orders.