A new method for estimating the level of natural fertility in populations practicing birth control

The natural fertility schedule of a population is the schedule of age-specific marital fertility we would observe if no birth control were being practiced. In natural fertility (no birth control) populations we can observe the natural fertility schedule directly, but in populations practicing birth control the natural fertility schedule is disguised by the marital fertility rates in those age intervals in which control is exercised, the marital fertility rates being below the natural rates. This paper elaborates a method for estimating the natural fertility schedules of populations practicing birth control. Two alternative models are presented, one nonlinear and one linear. The use of these models is then illustrated with reference to the Old Order Amish population of Lancaster County, Pennsylvania. It is shown that for Amish women born between 1860 and 1900 both the nonlinear and linear models yield an estimate of .843 as the ratio between Amish and Hutterite natural fertility schedules.     

Demographic aspects of fertility in Thailand

Abstract Data from a national rural and urban sample survey are analysed in order to examine various demographic aspects of fertility in Thailand. Marital fertility rates found for Thailand are among the highest in Asia. Particularly noteworthy is the persistence of high fertility at older ages of childbearing for rural women. Cumulative fertility shows a pronounced relationship with age at marriage and current marital status. Women who marry at an older age or who experience disruption of their marriages are clearly more likely to have fewer children ever born. Differences in both current and cumulative fertility are strongly associated with residence. Rural women who constitute the vast majority of Thai women, experience the highest fertility, Bangkok-Thonburi women experience the lowest fertility and provincial urban women are characterized by an intermediate fertility level which is closer, however, to the experience of their counterparts in the capital than in the countryside. Rural-urban fertility differences are mitigated but by no means eliminated by differences in infant mortality. In both rural and urban areas a positive association between cumulative fertility and infant morality is evident. Breast-feeding, commonly practised for extended periods-among both rural and urban Thai women, undoubtedly serves to some extent as an intervening variable in this relationship. A comparison of current fertility with cumulative fertility strongly suggests that a decline in marital fertility has been under way recently among urban women, especially those residing in the capital, but not at all among rural women. Although it seems safe to assume that the urban fertility decline results in large part from an increasing use of contraception among urban women, those still in the reproductive ages who were using or had previously used birth control were characterized by higher cumulative fertility than women who had never practised contraception. Evidently couples resort to family planning only late in the family building process after they have already achieved or exceeded the number of children they wish to have.     

Union Transitions Following the Birth of a Child to Cohabiting Parents

Despite a growing interest in the family trajectories of unmarried women, there has been limited research on union transitions among cohabiting parents. Using data from the 2002 National Survey of Family Growth, we examined how family complexity (including relationship and fertility histories), as well as characteristics of the union and birth, were associated with transitions to marriage or to separation among 1,105 women who had a birth in a cohabiting relationship. Cohabiting parents had complex relationship and fertility histories, which were tied to union transitions. Having a previous nonmarital birth was associated with a lower relative risk of marriage and a greater risk of separation. In contrast, a prior marriage or marital birth was linked to union stability (getting married or remaining cohabiting). Characteristics of the union and birth were also important. Important racial/ethnic differences emerged in the analyses. Black parents had the most complex family histories and the lowest relative risk of transitioning to marriage. Stable cohabitations were more common among Hispanic mothers, and measures of family complexity were particularly important to their relative risk of marriage. White mothers who began cohabiting after conception were the most likely to marry, suggesting that “shot-gun cohabitations” serve as a stepping-stone to marriage.     

Proximate determinants of Philippine fertility: 1983 levels and patterns

Data from the 1983 National Demographic Survey are used to analyze the proximate determinants of Philippine fertility in each of the 3 stages of family formation and to identify all of the direct and indirect factors affecting fertility levels and trends. 10,843 ever-married women and 12,771 children were included. The analysis pertains first to the starting patterns of family formation, the age at first birth, and the proximate determinants (age at menarche, age at first marriage/union, conception before first birth, fetal wastage first birth, interval between first marriage and first birth). Further analysis examines birth spacing patterns including the postpartum nonsusceptible period, the exposure interval and stopping patterns. Almost all births occur within marriage, and childbearing begins late at 22.5 years. However, 15.4% of first births are conceived premaritally. The mean age at first birth increases from younger to older cohorts. Urban women were slightly older (23.0 years) at the birth of their first child. Those with education below the 4th grade had first births 3.5 years earlier. Contraceptive use was low at 1.8% before first birth. Younger cohorts were more likely to use birth control and urban wives were more likely to use it than rural wives. 6.4% reported a first pregnancy ending in nonlive births, which were primarily spontaneous abortions (5.2%), stillbirths (1.0%), and induced abortions (.2%). 5.8% report never having been pregnant and 1.1% never having given birth to a live-born child. 20.4% were childless between the ages of 15-24 years, and 4.6% between 25-34 years. Childlessness was slightly higher among urban women (7.1%) than rural women (6.7%). A decreasing age at menarche has appeared; i.e., 13.6 years for the cohort 15-24 years, and 14.0 for the oldest cohort. By age 15, 82.9% had begun menstruating. The mean age at marriage is early at 20.7 years, and older cohorts tended to marry later at 21.4 years. Urban women marry a year later (21.4 years) than rural women. Lower educated women marry 4 years earlier. The mean length between first marriage and first birth was 18.4 months. In the younger cohorts, spacing patterns are shorter. Postpartum susceptibility is short. Return to sexual relations after a birth occurred at 2.8 months. The exposure time required to conceive is fairly long at 16.6 months and is attributed to contraceptive use, since coital frequency is high and temporary separation is infrequent. The average age at last birth is late at 37.6 years.     

Assesssing Cohort Birth Expectations Data from the Current Population Survey, 1971–1981

Data from the fertility supplements to the Current Population Survey from 1971 to 1981 indicate that in the aggregate, the lifetime birth expectations of married women 18 to 39 years old in 1971 will closely approximate their completed cohort fertility. During this period, the youngest group of women, 18 to 24 years old, delayed their childbearing; their short-term expectations (1971–76) were not realized, but they made up enough births in the latter half of the decade to enable them to attain their lifetime birth expectations. In retrospect, the “failure” of birth expectations data to predict the “period” fertility downswing in the 1970s resulted not from poor predictions of married women, but rather from unanticipated marital and subsequent childbearing patterns of women who were single at the beginning of the decade. The authors conclude that birth expectations are useful predictors of completed cohort fertility, if adjustments are made to incorporate changes in the proportions married within the birth cohort.     

Cohort estimates of nonmarital fertility for U.S. Women

Historical trends in U.S. nonmarital fertility have been compiled almost exclusively from vital statistics on births. This paper complements this historical record by providing cohort estimates of nonmarital fertility for cohorts of U.S. women spanning approximately 50 years of cohort experience. Life table estimates using retrospective marital and fertility histories in the June 1980, 1985, 1990, and 1995 Current Population Surveys reveal nonnegligible levels of nonmarital fertility historically. For women born between 1925 and 1929, nearly 1 in 10 had at least one nonmarital birth by age 30. For women born between 1965 and 1969, more than 1 of 4 had one or more nonmarital births by age 30, with roughly 1 of5 white, 3 of 5 black, and 1 in 3 Hispanic women having at least one nonmarital birth by age 30. Life table estimates reveal a twofold increase between ages 20 and 30 in the percentage of women with at least one child outside of formal marriage for all cohorts of white and Hispanic women, and an increase of roughly two-thirds for all cohorts of black women. I also document qualitative differences in nonmarital fertility by race/ethnicity, with the percentage of nonmarital births following a divorce or marital separation for white women approximately twice that for black or Hispanic women. Finally, I introduce a new measure, the cohort nonmarital fertility ratio (CNMFR), which provides a cohort complement to the standard period nonmarital fertility ratio. Conservative estimates reveal a roughly threefold increase in the CNMFR for women born from 1925-1929 to 1950-1954 for both whites and blacks, despite substantially higher levels of nonmarital fertility among black women. Overall, these findings reveal surprisingly high levels of nonmarital fertility for women born since the 1920s and confirm that nonmarital fertility has become an increasingly substantial component of overall U.S. fertility.     

Change of marital fertility in China from 1964 to 1981]

In 1982 the Chinese National Family Planning Commission conducted a nationwide (excepting Taiwan and Tibet) .001 random sampling of the total population to gather data on the fertility and age structures of married women. In comparing general marital fertility and standardized fertility, findings show that from 1964 to 1970 both rates averaged 225.1/1000. When family planning work began on a wide scale in 1971, the rates steadily declined, reaching 116.7/1000 in 1980. However, in 1967-68 the standard fertility rate rose by 21.34% due to the chaos of the Cultural Revolution, and in 1980-81 the rate increased by 13.2%, indicating that problems still remain in family planning. The total marital fertility rate dropped 2.84/1000 from 1964 to 1981. The rate of decline in rural areas was greater than in the cities, but the cities had a larger percentage decline than the countryside. In the 5-year periods of 1965, 1970, 1975, and 1980, marital fertility rates tended to decline in 1970 and 1975 among women aged 30-40 years because during those periods greater control was placed on women having multiple children. For 1980 and 1975, combined total rates for 15-19 year olds dropped 17.1%, but the combined total rates of 30-49 year olds dropped by 61.2%, indicating that in recent years the drop in marital fertility is mostly among those over 30 years of age.     

Schooling,marriage, and age at first birth in Madagascar

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.     

Does It Matter What She Wants? The Role of Individual Preferences Against Unmarried Motherhood in Young Women’s Likelihood of a Nonmarital First Birth

Most young people in the United States express the desire to marry. Norms at all socioeconomic levels posit marriage as the optimal context for childbearing. At the same time, nonmarital fertility accounts for approximately 40 % of U.S. births, experienced disproportionately by women with educational attainment less than a bachelor’s degree. Research has shown that women’s intentions for the number and timing of children and couples’ intent to marry are strong predictors of realized fertility and marriage. The present study investigates whether U.S. young women’s preferences about nonmarital fertility, as stated before childbearing begins, predict their likelihood of having a nonmarital first birth. I track marriage and fertility histories through ages 24–30 of women asked at ages 11–16 whether they would consider unmarried childbearing. One-quarter of women who responded “no” in fact had a nonmarital birth by age 24–30. The ability of women and their partners to access material resources in adulthood were, as expected, the strongest predictors of the likelihood of nonmarital childbearing. Nonetheless, I find that women who said they would not consider nonmarital childbearing had substantially higher hazards of fertility postponement and especially of marital fertility, even after controlling for race/ethnicity, mother’s educational attainment, family of origin intactness, self-efficacy and planning ability, perceived future prospects, and markers of own educational attainment and work experience into early adulthood.     

Baby boomlet for older mothers?

In recent years, a number of celebrities have begun childbearing after age 35. The phenomena of older first-time mothers has received a great deal of attention in the popular press. Are these celebrities indicative of a national trend? Does the increase in fertility portend a reversal of the declines in fertility which have been occurring since the baby boom? The present paper uses central and cumulative birth rates for cohorts of American white women born between 1882 and 1953 to investigate childbearing between ages 35 and 50. While there has been a noticeable upsurge in first birth rates for cohorts in their mid to late 30s in recent years, overall central birth rates for women in their 30s are among the lowest on record, with cumulative birth rates at record low levels. A major reason for this is that these women are having relatively few third and higher order births. These cohorts will need to have a relatively high proportion of births in their older years of childbearing in order to reach replacement level. However, attaining replacement level is unlikely because such a high proportion of women have remained childless at ages 35–40 and a relatively low proportion are having three or more children.     

The relationship between childbearing and transitions from marriage and cohabitation in Britain

In this article, we describe a general framework for the analysis of correlated event histories, with an application to a study of partnership transitions and fertility among a cohort of British women. Using a multilevel, multistate competing-risks model, we examine the relationship between prior fertility outcomes (the presence and characteristics of children and current pregnancy) and the dissolution of marital and cohabiting unions and movements from cohabitation to marriage. Using a simultaneous-equations model, we model these partnership transitions jointly with fertility, allowing for correlation between the unobserved woman-level characteristics that affect each process. The analysis is based on the partnership and birth histories that were collected for the 1958 birth cohort (National Child Development Study) aged 16-42. The findings indicate that preschool children have a stabilizing effect on their parents 'partnership, whether married or cohabiting, but the effect is weaker for older children. There is also evidence that although pregnancy precipitates marriage among cohabitors, the odds of marriage decline to prepregnancy levels following a birth.     

The effect of marital status at first birth on marital dissolution among adolescent mothers

The sequencing of marriage and first birth was expected to play an important role in the stability of marriage among adolescent mothers. We hypothesized that adolescent women who married prior to conception would have the lowest rates of marital disruption, followed by those who married between conception and birth. Adolescent women who gave birth prior to marriage were expected to suffer the highest rates of marital dissolution. The results provide partial support for our hypotheses. There is little difference in the probability of separation between adolescent mothers who had a postmarital conception and those who had a premarital conception but married before the birth. Having a premarital birth, however, significantly increases the probability of marital dissolution. We also hypothesized that marital status at first birth would have less effect on the probability of marital dissolution for blacks than for whites. This, too, is generally supported by our findings. Among black females, those with a premarital birth are the first to suffer a marital disruption, but by the end of ten years there is little difference in the probability of separation among the three marital status groups. In contrast, among white females, those with a premarital birth are the first to experience a disruption, and this differential persists over all subsequent marriage duration intervals. Thus, the sequencing of marriage relative to birth has similar short term effects for whites and blacks, but the effect for blacks is evident only in the short term. Ten years after the marriage, black adolescent mothers have similar rates of marital stability regardless of the sequencing of marriage. This is consistent with the findings of previous research and with our hypothesis; with the black family pattern of lower rates of marriage, higher rates of illegitimacy and higher divorce rates, the sequencing of marriage has no long lasting consequences on marital stability. Finally, our predicted decline in the effect of marital status at first birth over historical time also finds partial support. For white females there has been a change in the effect of marriage-first birth sequencing on separation over time. In the period encompassed by the women in our study, white adolescent mothers who married subsequent to the birth have been the most likely to experience a separation at all marriage duration intervals, but this differential narrows as age at interview declines. Among black females there has been no change in the effect of a premarital birth over time.(ABSTRACT TRUNCATED AT 400 WORDS)     

Outsourcing of Housework and the Transition to a Second Birth in Germany

The struggle that women face in reconciling their work and family roles is one of the main explanations proposed for the rapid decline in fertility rates in some developed countries. This study examines the role of the outsourcing of housework in reducing such role incompatibility and in increasing fertility among women in Germany—a country with below-replacement fertility rates, which enacted a series of large-scale schemes from the beginning of the 1990s that give incentives to households to outsource housework. Based on Goode’s role strain theory and by using data from the German Socio-Economic Panel, this study analyzed whether women who outsourced housework after the birth of their first child had a higher probability of having a second child. A survival analysis of 3990 person years demonstrates that, controlling for observables, the outsourcing of domestic labor is positively associated with a higher probability of a subsequent second birth in German women.     

Marital dissolution,remarriage, and childbearing

Earlier models of fertility hypothesize that marital dissolution and remarriage influence subsequent childbearing. This issue is examined by comparing the fertility of those in disrupted marriages with that of those in stable marriages. The results indicate that, by transferring women into a nonmarried status, marital dissolution decreases childbearing. The data also suggest that discord reduces fertility even before separation occurs—separated women had reduced fertility during the two years just before separation. It was found that marital dissolution without remarriage operates to truncate childbearing, thus decreasing family size. Dissolution followed by remarriage, however, lengthens the childbearing span of whites and has no influence on average family size; remarrying white women are able to make up for the childbearing lost between marriages. For nonwhites, we found that dissolution and remarriage increase the average time to childbirth, but, even more importantly, these events greatly decrease the number of children born.     

Models of contemporary Dutch family building

Summary Recent data suggest that the level of use of oral contraceptives in the Netherlands is perhaps the highest in the world. Moreover, the greatest recent change in family building patterns is the tendency of newly weds to postpone their first birth. A micro-simulation model was developed to test the effect on fertility of such a change. An attempt was made to employ input data compatible with conditions obtaining in the Netherlands, and the distributions of family building patterns were based on recent survey evidence. The aim was not to duplicate Dutch fertility, but rather to estimate the range over which marital duration-specific fertility can be expected to vary with an increase in the proportion of couples who space their first birth. Such an increase was found to lower fertility dramatically after five years of marriage, although completed fertility was seen to vary very little. This result indicates the care that must be taken in ascribing a decline in the fertility of the early years of marriage to an overall fertility decline.     

Explaining the Gender Wealth Gap

To assess and explain the United States’ gender wealth gap, we use the Wisconsin Longitudinal Study to examine wealth accumulated by a single cohort over 50 years by gender, by marital status, and limited to the respondents who are their family’s best financial reporters. We find large gender wealth gaps between currently married men and women, and between never-married men and women. The never-married accumulate less wealth than the currently married, and there is a marital disruption cost to wealth accumulation. The status-attainment model shows the most power in explaining gender wealth gaps between these groups explaining about one-third to one-half of the gap, followed by the human-capital explanation. In other words, a lifetime of lower earnings for women translates into greatly reduced wealth accumulation. After controlling for the full model, we find that a gender wealth gap remains between married men and women that we speculate may be related to gender differences in investment strategies and selection effects.     

Fertility and economic activity of women in Guatemala city, 1964

Data from a five percent census sample reveal that in Guatemala City in 1964 economically active women, especially domestic servants, had lower cumulative fertility than inactive women, partly because larger proportions of them had never married and were childless. However, even among ever married mothers there was a substantial differential, which was not due to differences in age at first birth. With respect to all women, cross tabulation and regression analysis show that age, marital status and educational attainment were more strongly associated with fertility than was activity status, but the latter also had a significant net association. Selection for sterility was not likely. Being contrary to expectations expressed in the literature, the very low fertility of the domestics received further attention. Live-in domestics had considerably lower fertility than those who lived out, which was also the case in the United States in 1960. These data and other evidence strongly suggest that this differential is due to a widespread employer preference for single or childless women. The concept of role incompatibility is therefore inapplicable to domestic servants. These findings add to the considerable evidence showing lower fertility among economically active women in large urban places in Latin America.     

A decomposition of trends in the nonmarital fertility ratios of blacks and whites in the united states, 1960–1992*

We use a method of standardization and decomposition developed by Das Gupta to update Smith and Cutright’s analysis of demographic factors responsible for increases in the nonmarital fertility ratio (illegitimacy ratio) among blacks and whites in the United States. We create standardized rates for each year between 1960 and 1992, and consistent, exhaustive decompositions of the nonmarital fertility ratio for any interval during this period in terms of four components: (1) the age distribution of women of reproductive age, (2) the proportion of women unmarried at each age, (3) the age-specific birth rates of married women, and (4) the age-specific birth rates of unmarried women. Nonmarital fertility ratios are much higher among blacks than among whites, but both increased monotonically from 1960 to 1992. During the last 10 years, each increased by nearly 10 percentage points. Increases in the proportion of women not married, at all ages, account for the preponderance of the increase in black nonmarital fertility ratios. Increasing rates of unmarried childbearing, however, have played a role during the most recent decade (1983–1992). For whites, from 1960 until 1975, declines in marital fertility were most important in producing increases in the proportion of children born out of wedlock. Since then, these proportions have increased primarily because of increases in unmarried women s birth rates, and secondarily because of declines in the proportion of women who are married. These trends are consistent with arguments that emphasize declining economic incentives to marry and reduced access to, and acceptability of, abortion.     

The change of fertility and factors impacting it in Shanghai City in the past thirty years]

In 1981 a 3% random sampling of women born between 1931-66 was taken in Shanghai to study their menstrual and marital histories, pregnancies, contraceptive use, education, and occupation. In the last 30 years the fertility rate and the rate of natural population increase began to decline beginning around 1957-58. The changes in fertility rate fall into 3 periods: 1) between 1958-61 the fertility rate fell from 238.6/1000 to 159.2/1000, averaging 26.5/1000 annually; there was a slight period of stability from 1961-63; 2) between 1963-67 it fell from 155.8/1000 to 56.3/000, averaging 24.9/1000 annually and between 1967-68 there was a slight increase; and 3) between 1968-74 it fell from 63.2/100 to 26.4/1000, averaging 6.1/1000 annually. The fertility rate of various age groups also declined during the last 30 years. The average number of children for married women was 1.92. Factors influencing the fertility rate include: 1) birth control policy: the changes in the fertility rates were dominated by the birth control policy; for instance, from 1956-60, after late marriages were officially advocated, the average age at 1st marriage for men was 1.64 years older than before; between 1962-64, those women with more than 3 children were sterilized. 2) Education: the higher the educational attainment, the later was the age at 1st marriage, the more effective was the use of contraceptives and the lower the standard was for fertility; 3) occupation: the type of job influenced the age at marriage, as well as the frequency of miscarriage and live births; 4) attitude towards children: the total number of children women reported they would like averaged out to be 1.7; 5) urban and rural differences: the fertility rate for Shanghai City was not only lower than for Shanghai County, it fell at a faster rate; 6) changes in the age structure of fertile women affected the fertility rate; and 7) others: nutrition, the ability to propagate, age at 1st marriage, plus economic and social factors all affected fertility.