Age at marriage and timing of the first birth

Summary An attempt has been made to measure the effect of age at marriage of brides on the timing of the first birth. In Australian vital statistics, first nuptial confinements have been tabulated by age of mothers and by single years of marriage duration in single months for the first two years and by single years for all other durations since 1916. A simple technique has been used to link such data with marriage cohorts. The study briefly reviews the prevailing patterns of the timing of first births by mothers' age at marriage and changes in this pattern since the marriages of the 1925/9 period. The analysis shows that after a period of relative stability of family formation patterns in the 1950s and early 1960s, women married in the late 1960s started postponing the first birth beyond the first two years of marriage. It is suggested that a fraction of the decline in total births recorded in Australia since 1972 can be attributed to the postponement of first nuptial confinements by women married in the late 1960s and early 1970s.     

Age and marital status at first birth and the pace of subsequent fertility

Taking care to minimize the truncation bias inherent in cross-sectional data and controlling for other variables, this paper demonstrates the strong effects of both age and marital status at first birth on the pace of subsequent fertility. These effects are particularly strong in the interval immediately following the first birth but persist even into the fourth interval. Important differences are found with respect to the experience of rapid fertility, rather than in the mean lengths of intervals. These results add to the growing attention to the social dimensions of age as a variable in fertility processes.     

Age and birth date reporting in Thailand

Researchers analyzed age and birth data reporting using data on 6775 ever married women 15-49 years old collected between March-June 1987 for the Thailand Demographic and Health Survey. 80% of the women accurately stated their age within 1 year of actual age. Further they could state with at least equal accuracy the birth dates of their children. Moreover the ages of younger children were quite accurate since they stated age in units less than whole years but misreporting increased with children's age. Thus the proportion of children who were really 1 year old but reported to be 1 year old was smaller than that of children who really were 1 year old but reported to be 2 years old. This pattern continued until that time when children's ages were no longer reported in greater detail than whole years. The researchers found that undercounts of younger children occurred when stated age was the basis for age tabulations. Most people in Thailand considered their age to be the difference between the present year and the year of birth. They did not take into account whether the present year's birthday passed or not. This practice resulted in a considerable percentage of the population for whom stated age was 1 year older than completed age. In fact, it was quite common, at least in rural areas, for Thasis to not even acknowledge birthdays. They did tend to know their lunar month and animal birth year, however. In conclusion, this study revealed that age data in Thailand are probably more affected when inquiries occur early in the year than later in the year. The researchers called for constant updating research since the social and cultural dynamics which affect age and birth data reporting are always changing.     

The relationship of the crude birth rate and its components to social and economic development

Using well-known techniques of regression analysis, we decompose the crude birth rate into six analytical components, indicating illegitimacy, the marriage rate, legitimate fertility, and sex and age composition. All the components except sex structure are important in determining differences in crude birth rates across countries of the world. The model is elaborated by showing how economic development affects the crude birth rate through its basic demographic components.     

The imbalance of sex ratio at birth,and its causes and countermeasures in China

This news brief focuses on the sex ratio at birth (SRB) in China, its causes, and remedial efforts. A SRB has been evident since the 1980s. The SRB increased from 108.48 male/100 female births to 116.30 male/100 female births during 1981-94. A normal SRB in China during 1940-94 would have been 107 male/100 female births. The SRB rose every year after 1985, with the exception of 1988. Male births increased, while female births decreased. SRB declined with age. The sex ratio in 1991, was 112.3 for children aged 0-4 years, 108.38 for children aged 5-9 years, and 106.56 for children aged 10-14 years. SRB values were higher in more populous provinces and lower in less populous provinces. SRB values were lower in northwestern China than in southeastern China. SRB values of minorities were lower than the Han ethnic group. A high SRB will increase the proportion single in later years. In 1990, 7.86 million people aged 30-40 years were single, of whom 94.32% were males. The SRB is caused by second, third, or higher birth orders. In 1993, sex ratios were 105.60 for first births, 130.22 for second births, and 126.12 for third births. The imbalance is attributed to a preference for sons as inheritors of blood ties and as family physical laborers. The imbalance is due to strict birth control and people's refusal to report female births. There is a need to increase awareness of the consequences, to increase old-age pensions and social security, to increase women's status, and to prohibit sex determination of a fetus. The family structure should emphasize its consumptive capacity rather than its function as a production unit.     

Effect of Conflict on Age at Marriage and Age at First Birth in Rwanda

Using Rwanda Demographic and Health Survey 2005 data, we estimate a Cox proportional hazard model to identify the determinants of age at marriage and age at first birth and whether these decisions were affected by conflict. We find that women living in clusters accounting for a larger proportion of sibling deaths in 1994, the year of the genocide, were more likely to marry later and have children later compared with those living in clusters accounting for a lower proportion of sibling deaths. Women living in regions with higher levels of under-five mortality were more likely to have their first child earlier compared with women living in regions with lower infant mortality. The age at marriage was probably affected by two reasons: the change in age structure and sex ratio of the population following the genocide, and the breakdown of kinship in the case of women who lost their siblings.     

Age at marriage and marital fertility

In recent years much criticism has been levelled against the use of gross and net reproduction rates as measures of replacement in any period of marked change. In this paper the author considers these criticisms and outlines a method which would yield more information on the problem of replacement and which would also eliminate the influence of varying ages at marriage on fertility when different groups or periods of time are compared. The use of this method is illustrated by an application to the fertility statistics of England and Wales and of different counties.     

Age at marriage and proportions marrying

This paper deals with the recent widespread increase in marriage rates in the Western world. The principal materials used are data on the proportions single in each age group at various times. These data are used to estimate how far the ‘marriage boom’ has reflected decreases in the proportions of persons remaining single throughout life or reductions in the age at marriage of those who do marry. The conclusion is that changes of both types have occurred; the mean age at marriage has been declining in several countries at a rate of more than one-tenth of a year per annum. A number of ancillary technical problems relating to the analysis of nuptiality are discussed.     

Race,intervening variables,and two components of low birth weight

The low birth weight (LBW) gap between blacks and whites has remained largely unexplained in past research. Most previous research on the topic has focused on LBW as a single entity, and without using a causal framework for. analysis. The present study examines the determinants of race differences in the two main components of LBW-preterm birth (PRETERM) and intrauterine growth retardation (IUGR)-within a partially causal framework that includes social and proximate explanatory variables. The data come from the 1988 National Survey of Family Growth. This study asks, first, through what intervening variables do race and other exogenous sociodemographic variables operate to raise the risk of these adverse pregnancy outcomes? Second, what are the determinants of the two components of LBW when all explanatory variables are included in the model? The findings reveal differences in how race (and other exogenous variables) act through downstream variables to affect PRETERM and IUGR, as well as differences in the net determinants of these pregnancy outcomes. The models are better able to account statistically for race differences in IUGR (which is explained by intervening sociodemographic, attitude, and behavior variables) than in PRETERM (which is explained partly by intervening health variables).     

Age at motherhood in Japan

The paper analyzes factors influencing the age of motherhood in Japan, using both cross-sectional and time-series data. Both hazard rate and time series analyses support the hypothesis that better women's earning opportunities, as indicated by their educational attainments and relative pay, encourage Japanese women to marry and become mothers later in their lives. But both these analyses indicate that the trend toward later marriage and motherhood in Japan cannot be fully accounted for by improvements in women's educational attainments and earning opportunities, and the hazard analysis indicates that the strength of the trend increases with a woman's educational attainment.We are grateful to Shigemi Kono, former Director-General of the Institute of Population Problems, for providing us the aggregate data on the first birth probability, and the Population Problems Research Council of the Mainichi Newspapers for permitting us to use their survey data. We also thank Robert D. Retherford and two anonymous referees for helpful comments on earlier versions of the paper, Kazuichiro Iizuka and Rikiya Matsukura for their research assistance, and the American Family Life Assurance Company of Japan for its financial support for the research.     

Age at the onset of menopause and its influencing factors in Turkish women in a rural area

This study was performed to identify menopausal age and its determining factors in women over 40 residing in the Dogubeyazit district of Agri, located in Eastern Turkey. This cross-sectional study was performed on a sample of 1,068 women, selected by simple random sampling among all district health center records of women aged 40 and greater, who were each attributed a random serial number. While 35.6% of the subjects had not yet reached menopause, 60.5% had entered it spontaneously and 3.9% surgically. Average age at spontaneous menopause was 47.4 ± 3.7 years and that of surgical menopause 45.1 ± 5.0. Age at marriage, age of last pregnancy, and the age of the subject’s mother at menopause affected menopausal status. Identifying menopausal age and its determining factors may modify the menopausal status of women and their management of the perimenopausal period.     

Recent trends in multiple-caused mortality 1968 to 1982: Age and cohort components

Declines in mortality at advanced ages have been observed recently in the United States. These declines have been related to a reduction in the risk of major circulatory diseases, such as stroke and heart disease. In this paper we examine the contribution of two additional major factors in those declines. The first is the effect of conditions associated with circulatory diseases. This effect can be examined by using multiple-cause mortality data in which all conditions reported by the physician on the death certificates are recorded. The second is the contribution of cohort mortality differentials to temporal changes. If major cohort differentials are identified, we may be able to determine if recent declines in mortality are likely to continue-and to what levels. Such insights would be useful both in improving projections of the size and age structure of the U.S. elderly population and its entitlement groups and in helping to identify future patterns of needs for preventive and other health services.     

Age at baptism in pre-industrial England

Abstract The adequacy of English parish registers as demographic sources has been a subject for much debate.(1) Most attention has been directed to the problem of how far the population at large continued to use the sacraments ofthe Established Church in the late eighteenth and early nineteenth centuries, especially in areas affected by urban growth or Nonconformity. But the more general problem of how far the ecclesiastical registers of ceremonies are acceptable substitutes for registers of vital events also deserves some attention.     

Age at baptism in pre-industrial England

The adequacy of English parish registers as demographic sources has been a subject for much debate.¹ Most attention has been directed to the problem of how far the population at large continued to use the sacraments ofthe Established Church in the late eighteenth and early nineteenth centuries, especially in areas affected by urban growth or Nonconformity. But the more general problem of how far the ecclesiastical registers of ceremonies are acceptable substitutes for registers of vital events also deserves some attention.     

Sex ratio at birth for urban and rural areas

Previous studies show that sex ratio at birth in China's urban areas is usually higher than that of rural areas. The higher proportion of 1st births in urban areas was once taken to explain the cause for the higher sex ratio. The data of the 1982 fertility sampling survey show that the sex ratio at birth during the period from 1964 to 1981 remains higher in the urban areas (108.0) than in the rural areas (107.8). Further studies are yet needed on the differentials in sex ratios at birth between urban and rural areas and on their causes. The sex ratio in 1981 of the 29 provinces, municipalities and autonomous regions in China's mainland was 108.5, somewhat higher than that of most countries in the world. 2 things account for the occurrence. 1 is that, biologically, certain particularities may exist in the sex ratio at birth of China's population, for the ratio varies with ethnic groups, nationalities and regions. The other is that, sociologically, female infants may be underreported in some areas and the phenomenon of infanticide left over by history still exists in some isolated cases. These surveys suggest that a certain specific characteristic does exist in the sex ratio at birth of China's urban areas, but they also contribute to the explanation of the higher sex ratio at birth of the total population of the country.     

Age of entry into marriage and the date of the initiation of voluntary birth control

It is widely known that modern economic development has been accompanied by the initiation and spread of effective limitation of fertility, and that generally the populations which experienced development at a late date also had a belated reduction in childbearing. Here a surprising relation is found between (and within) broad regions: the areas in which traditional age of entry into marriage was late were the areas in which marital fertility was reduced first.     

Age at Arrival and Life Chances Among Childhood Immigrants

This study examines the causal relationship between childhood immigrants’ age at arrival and their life chances as adults. I analyze panel data on siblings from Norwegian administrative registries, which enables me to disentangle the effect of age at arrival on adult socioeconomic outcomes from all fixed family-level conditions and endowments shared by siblings. Results from sibling fixed-effects models reveal a progressively stronger adverse influence of immigration at later stages of childhood on completed education, employment, adult earnings, occupational attainment, and social welfare assistance. The persistence of these relationships within families indicates that experiences related to the timing of childhood immigration have causal effects on later-life outcomes. These age-at-arrival effects are considerably stronger among children who arrive from geographically distant and economically less-developed origin regions than among children originating from developed countries. The age-at-arrival effects vary less by parental education and child gender. On the whole, the findings indicate that childhood immigration after an early-life formative period tends to constrain later human capital formation and economic opportunities over the life course.     

外出经历对农村妇女初婚年龄的影响

本文应用事件史分析方法，讨论了农村妇女初次外出时间与初婚年龄的关系。所用数据来自２０００年安徽、四川省４个县的问卷调查。研究发现，农村妇女的外出经历及外出时间对她们的初婚年龄有显著影响。在控制了其他变量的情况下，婚前曾经外出的妇女初婚年龄较大。婚前外出的流入地为外省或城市的妇女，初婚年龄大于其他婚前外出过的妇女。本研究结果显示农村到城市的劳动力流动有助于提高农村年轻妇女的初婚年龄。