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1.

Substantial regularities characterize the transition to stability that follows a shift from one set of vital rates to another. The new vital, rates interact with the population's initial age composition and generate birth waves whose amplitude and attenuation depend on the ratio of ultimate to initial growth and on the new pattern of stable net maternity. A greater change in growth and a later stable net maternity pattern produce larger fluctuations in the number of births. Stabilization begins at the youngest ages and proceeds upward. Sixty years after the shift, the birth waves have largely disappeared and the proportion under age 15 approximates the stable level implied by the new rates. Those patterns are manifest in the stabilization of both observed and Coale‐Demeny model stable populations.

When fertility falls, the new stable population has a larger fraction at all ages above (approximately) 30, with greater changes characterizing the extremes of life. Fifteen years after the fall, there is a trough in the number at ages 0–14. Sixty years after the fall, when the largest pre‐decline cohort is age 60–74 and the smallest post‐decline cohort is age 45–59, there is a surge in the relative size of the elderly population. Thus after two generations, the birth waves produced by a rapid decline in fertility accentuate the effects of population aging.  相似文献   

2.
To date, many arguments to explain altruistic behavior were based on `kin selection'. This note shows that evolution can sustain altruism even if the players are not necessarily genetically linked. Depending on the payoff parameters in a prisoner's dilemma game, there can be four distinct types of equilibria, for each of them the proportion of altruists in the population is described. The author is grateful to an anonymous referee for valuable comments. Responsible editor: Alessandro Cigno.  相似文献   

3.
Population and Environment - The effects from rising temperatures, a symptom of climate change, have become a significant concern. This study finds that one additional day with a maximum...  相似文献   

4.
The registration of vital events in the United States has always been under the authority of State and local areas. The preparation of national birth statistics has been made possible through a co-operative working arrangement between the Federal Government and the States. This paper traces the development of registration systems in the United States from colonial days to the present period. The absence of adequate registration systems throughout the country, during the nineteenth century, led to the use of data collected in the decennial population censuses of 1850–1900 for estimating birth rates. This procedure was abandoned because of the unreliability of the results. Steps leading to the formation of the national birth-registration area in 1915, when it included ten States and the District of Columbia, and. activities resulting in its completion in 1933 are discussed.

A major portion of the paper outlines the nation-wide test of birth-registration completeness conducted in 1940 in conjunction with the decennial census of population. Important results of the test are presented, and the methodology is explained. A similar test is being carried out in 1950. Data derived will be used to focus attention on local areas requiring registration promotion. Correction factors for statistical series based on registered events will also be obtained. The final section of the paper indicates the steps States are taking to improve quality of reporting on the birth record. Changes in the content of the standard certificate of live birth since 1915 are summarized and the statistics tabulated from birth certificates detailed.  相似文献   

5.
The Cebu Longitudinal Health and Nutrition Survey is used to examine the roles of women’s nutrition and infant feeding in determining time from birth to menses and time from menses to conception. The analysis sample includes 2,648 Filipino women followed for 24 months postpartum. Recently devised statistical estimation techniques to control for unobserved heterogeneity and endogeneity are employed in estimating a two-state hazard model. Low body mass index and lower dietary fat intake are associated with increased duration of postpartum amenorrhea. Contraceptive use, high dietary fat consumption, higher parity, and absence of spouse predict a longer waiting time to conception once menses have returned. Simulation of the hazard model is used to examine the effects of the key nutrition and lactation factors.  相似文献   

6.

Problem

Birth preferences, such as mode and place of birth and other birth options, have important individual and societal implications, yet few studies have investigated the mechanism which predicts a wide range of childbirth options simultaneously.

Background

Basic beliefs about birth as a natural and as a medical process are both predictive factors for childbirth preferences. Studies investigating birth beliefs, preferences, and actual birth are rare.

Aim

To test a predictive model of how these beliefs translate into birth preferences and into actual birth related-options.

Methods

Longitudinal observational study including 342 first-time expectant mothers recruited at women’s health centres and natural birth communities in Israel. All women filled out questionnaires including basic birth beliefs and preferred birth options. Two months postpartum, they filled out a questionnaire including detailed questions regarding actual birth.

Findings

Stronger beliefs about birth being natural were related to preferring a more natural place and mode of birth and preferring more natural birth-related options. Stronger beliefs about birth being medical were associated with opposite options. The preferences mediated the association between the birth beliefs and actual birth. The beliefs predicted the preferences better than they predicted actual birth.

Discussion

Birth beliefs are pivotal in the decision-making process regarding preferred and actual birth options. In a medicalized obstetric system, where natural birth is something women need to actively seek out and insist on, the predictive powers of beliefs and of preferences decrease.

Conclusion

Women’s beliefs should be recognized and birth preferences respected.  相似文献   

7.
Gender preference, particularly son preference, is believed to sustain high fertility in many Asian countries, but previous research shows unclear effects. We examine and compare gender-preference effects on fertility in two otherwise comparable populations in Bangladesh that differ markedly in their access to and use of contraception. We expect, and find, stronger effects of gender preference in the population that has more access to contraception and higher levels of contraceptive use. Thus gender preference may emerge as a significant barrier to further national family planning efforts in Bangladesh. We find that if a woman has at least one daughter, the risk of a subsequent birth is related negatively to the number of sons. Women with no daughters also experience a higher risk of having a subsequent birth; this finding suggests that there is also some preference for daughters. Son preference is strong in both the early and later stages of family formation, but women also want to have at least one daughter after having several sons.  相似文献   

8.
The low school attainment, early marriage, and low age at first birth of females are major policy concerns in less developed countries. This study jointly estimated the determinants of educational attainment, marriage age, and age at first birth among females aged 12–25 in Madagascar, explicitly accounting for the endogeneities that arose from modelling these related outcomes simultaneously. An additional year of schooling results in a delay to marriage of 1.5?years and marrying 1?year later delays age at first birth by 0.5?years. Parents’ education and wealth also have important effects on schooling, marriage, and age at first birth, with a woman's first birth being delayed by 0.75?years if her mother had 4 additional years of schooling. Overall, our results provide rigorous evidence for the critical role of education—both individual women's own and that of their parents—in delaying the marriage and fertility of young women.  相似文献   

9.
Health-service researchers, policy analysts, and politicians face several problems in attempting to evaluate health care programs and make relevant policy decisions. The possible rôle of social indicators is discussed in these regards and is applied in an important health care context, the utilization of ancillary health services by the elderly. A Western Canadian research study substantiates the academic and applied value of the social indicators approach with respect to health services planning, research, and policy decision-making.  相似文献   

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BackgroundThere is increasing evidence that fear of birth can have long-term effects on the childbearing woman and the method of birth.AimTo examine differences between five hospitals in Norway in the occurrence of fear of birth, counselling received and method of birth.MethodSource data was from the Norwegian cohort of the Bidens study and retrieved through a questionnaire and electronic patient records from five different hospitals in Oslo, Drammen, Tromsø, Ålesund and Trondheim, which included 2145 women. The Wijma Delivery Expectancy Questionnaire measured fear of birth, and a cut-off of ≥85 was used to define fear of birth.ResultsIn total, 12% of the women reported fear of birth, with no significant differences between the different units. A total of 8.7% received counselling according to hospital obstetrical records, varying significantly from 5.7% in Drammen to 12.7% in Oslo. Only 24.9% of the women with fear of birth had counselling at their hospital. All the units provided counselling for women with fear, but the content varied. Overarching aims included helping women develop coping strategies like writing a birth plan and clearing up issues regarding prior births. A secondary objective was to prevent unnecessary caesarean section. Both primi- and multiparous women who reported fear of birth had a twofold increased risk of a planned caesarean section.ConclusionThere were no differences between five Norwegian hospitals regarding the occurrence of fear of birth. Counselling methods, resources, level of commitment and the number of women who received counselling varied; thus, hospital practices differed.  相似文献   

13.
During the last fifty years there have in many countries been large movements in the growth of labor productivity, real wage rates, the rate of interest, and the household savings ratio. In this paper we use an overlapping generations model to study if demographic shocks, like the baby boom, can generate the kind of movements observed. Simulations show this is indeed the case. We also study the interactions between a pay-as-you-go pension system and demographic disturbances.We are grateful to Laurence Ball, Alex Cukierman and two anonymous referees for helpful comments.  相似文献   

14.
An investigation into the timing of first births in relationship to the date of marriage in Massachusetts confirmed the finding of previous national and local birth timing studies that first births likely to have been conceived before the marriage of their parents constitute a substantial proportion of all first births. The differential frequency of premaritally conceived births among various subgroups appeared to account for the variation noted in the overall timing patterns of first births after marriage. Data were gathered through linkage of certificates of birth of a sample of legitimate first children with the marriage record of their parents. Analysis of the marriage-first birth interval by maternal age and race, type of marriage ceremony, and occupation of the bride and groom were conducted and comparisons with previously published data were made. Separate consideration was given to the frequency and characteristics of those births likely to be premaritally conceived and those likely to have been conceived after the wedding.  相似文献   

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16.
The influence of women’s birth parity and accumulated market skills on their current labor force participation and birth expectations is examined within a sequential choice framework, Analysis of household data from the 1973 Philippines National Demographic Survey suggests these patterns: (a) women who have accumulated larger families work less in the current period and anticipate fewer additional births; (b) women with more past work experience tend to work more hours in the current period; and (c) work experience appears to have only a weak negative effect on birth expectations among older women.  相似文献   

17.
We used six waves of the National Longitudinal Survey of Youth-Child Data (1986-1996) to assess the relative impact of adverse birth outcomes vis-à-vis social risk factors on children's developmental outcomes. Using the Peabody Individual Achievement Tests of Mathematics and Reading Recognition as our outcome variables, we also evaluated the dynamic nature of biological and social risk factors from ages 6 to 14. We found the following: (1) birth weight is significantly related to developmental outcomes, net of important social and economic controls; (2) the effect associated with adverse birth outcomes is significantly more pronounced at very low birth weights (< 1,500 grams) than at moderately low birth weights (1,500-2,499 grams); (3) whereas the relative effect of very low-birth-weight status is large, the effect of moderately low weight status, when compared with race/ethnicity and mother's education, is small; and (4) the observed differentials between moderately low-birth-weight and normal-birth-weight children are substantially smaller among older children in comparison with younger children.  相似文献   

18.
A theoretical model is developed in which the market for teachers is linked to the time path of fertility in the general population. The model is simple in its components but when the components are combined they form a complex long-memory dynamic system. Simulation experiments are carried out to investigate the effects of changes in fertility rates on supply/requirements imbalances in the teachers' market, the median age of teachers, and other variables. The model (and by implication, the real-world system) is found to be highly volatile in response to fertility variations.This study was supported by a grant from the Social Sciences and Humanities Research Council of Canada. The authors are grateful for the able research assistance provided by Guy Brockington and Renqun Wang and for the helpful comments of the referees.  相似文献   

19.
Serious psychological distress and falls are two major public health problems among the elderly. This study aims to test the hypothesis that although serious psychological distress can increase the risks of falls among the elderly, it tends to affect elderly women more than elderly men. Data of this study are from the 2011 California Health Survey Interviews (CHIS). We extracted a sample of 13,153 respondents aged 65 and older for this study, including 8,087 females and 5,066 males. We tested both unadjusted and adjusted interaction effects using bivariate and multivariate logistic regression analysis. Elderly women with serious psychological distress had the greatest likelihood of falls as compared to men with serious psychological distress and men and women without serious psychological distress. With respect to the covariates, limitations of physical activity and poor self-rated health status, Asian race, and older age were more likely to be associated with falls. This study provides further information on sex disparities of falls among the elderly such that serious psychological distress has a greater impact on falls for elderly women than elderly men. Thus, the findings of our studies suggest that mental health services and intervention can be useful to prevent falls for elderly women.  相似文献   

20.
Cohen  Joel E. 《Demography》1975,12(1):35-55
Demography - Based on parish registers, demographic histories of Crulai (France), Tourouvre-au-Perche (France), and Geneva (Switzerland) established the childhood mortality experienced by complete...  相似文献   

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