Preference for Sons,Family Size,and Sex Ratio: An Empirical Study in Korea

This study investigates the effects of son preference on sex ratio and fertility at the family level, utilizing World Fertility Survey data for Korea, whose population is known to have a strong preference for sons and a fairly high level of contraceptive use. The sex ratio (number of males per 100 females) of siblings in small families is considerably higher than in large families. The sex ratio of last-born children in families of any size is markedly higher than that of the previous children. The sex distribution of children for a given family size, if less than five, deviates significantly from the Bernoulli sequence. The observed frequency of all-girl families is especially small in comparison with the expected value. The sex of the last child strongly influences couples' decision making regarding additional births in all steps of family building except for bearing a second child. In increasing their families to moderate size, parents appear to take into consideration the sex distribution of all earlier births.     

Relative cohort size: source of a unifying theory of global fertility transition

Using United Nations estimates of age structure and vital rates for 184 countries at five‐year intervals from 1950 through 1995, this article demonstrates how changes in relative cohort size appear to have affected patterns of fertility across countries since 1950—not just in developed countries, but perhaps even more importantly in developing countries as they pass through the demographic transition. The increase in relative cohort size (defined as the proportion of males aged 15–24 relative to males aged 25–59), which occurs as a result of declining mortality rates among infants, children, and young adults during the demographic transition, appears to act as the mechanism that determines when the fertility portion of the transition begins. As hypothesized by Richard Easterlin, the increasing proportion of young adults generates a downward pressure on young men's relative wages (or on the size of landhold‐ings passed on from parent to child), which in turn causes young adults to accept a tradeoff between family size and material wellbeing, setting in motion a “cascade” or “snowball” effect in which total fertility rates tumble as social norms regarding acceptable family sizes begin to change.     

The momentum of mortality change

Mortality change is not usually assigned much importance as a source of population growth when future population trends are discussed. Yet it can make a significant contribution to population momentum. In populations that have experienced mortality change, cohort survivorship will continue varying for some time even if period mortality rates become constant. This continuing change in cohort survivorship can create a significant degree of mortality-induced population change, a process we call the 'momentum of mortality change'. The momentum of mortality change can be estimated by taking the ratio of e0 (the period life expectancy at birth) to CAL (the cross-sectional average length of life) for a given year. In industrialized nations, the momentum of mortality change can attenuate the negative effect on population growth of declining fertility or sustained below-replacement fertility. In India, where population momentum has a value of 1.436, the momentum of mortality change is the greatest contributor to its value.     

The momentum of mortality change

Mortality change is not usually assigned much importance as a source of population growth when future population trends are discussed. Yet it can make a significant contribution to population momentum. In populations that have experienced mortality change, cohort survivorship will continue varying for some time even if period mortality rates become constant. This continuing change in cohort survivorship can create a significant degree of mortality-induced population change, a process we call the ‘momentum of mortality change’. The momentum of mortality change can be estimated by taking the ratio of e ₀ (the period life expectancy at birth) to CAL (the cross-sectional average length of life) for a given year. In industrialized nations, the momentum of mortality change can attenuate the negative effect on population growth of declining fertility or sustained below-replacement fertility. In India, where population momentum has a value of 1.436, the momentum of mortality change is the greatest contributor to its value.     

Migration and Intergenerational Replacement in Europe

There are long‐standing concerns over low fertility levels in Europe and an increasingly important debate on the extent to which migration can compensate for below‐replacement fertility. To inform this debate, a wide array of indicators have been developed to assess the joint influence of fertility, mortality, and migration on birth replacement and intergenerational replacement. These indicators are based on various models and assumptions and some are particularly data demanding. In this article we propose a simple method to assess how far migration alters the extent of replacement for a birth cohort as it ages. We term the measure the overall replacement ratio (ORR). It is calculated by taking the size of a female birth cohort at selected ages divided by the average size of the cohorts of mothers in the year of birth. We present estimates of the ORR for a range of European countries representing different replacement regimes. We demonstrate that for many countries net migration has become a key factor in their population trends during the last few decades.     

New strategies for slowing population growth

Growth of world population over the next 100 years, until the year 2100, will produce an estimated 11.5 billion people. The past focus on reducing rapid population growth exclusively through family planning has not been sufficient. Population policy needs to be broadened to include health care, education, and poverty reduction. The population policy recommendations of Population Council Vice-President John Bongaarts and Senior Associate Judith Bruce were to reduce unwanted pregnancies by expanding services that promote reproductive choice and better health, to reduce the demand for large families by creating favorable conditions for small families, and to invest in adolescents. The Population Council 1994 publication "Population Growth and Our Caring Capacity" outlined these issues. Another similar article by John Bongaarts appeared in the journal "Science" in 1994. In developing countries, excluding China, about 25% of all births are unwanted; 25 million abortions are performed for unwanted pregnancies. The provision of comprehensive family planning programs will go a long way toward achieving a reduction in unwanted pregnancies. In addition, changes are needed in male control over female sexuality and fertility and in cultural beliefs that are obstacles to use of contraception. Stabilization of population at 2 children per family will not occur unless there is a desire for small families. In most less developed countries, large family sizes are preferred. Governments have an opportunity to adopt policies that reduce economic and social risks of having small families. This can be accomplished through the widespread education of children, a reduction in infant and child mortality, improvement in the economic and social and legal status of women, and provision of equitable gender relations in marriage and child rearing. The rights of children to be wanted, planned, and adequately cared for need to be supported. These aforementioned measures will help to reduce fertility, provide support for small families, and justify investment in social development. Population momentum will keep population growing for some time even with replacement level fertility. Investment in adolescents through enhancement of self-esteem and promotion of later childbearing can lengthen the span between generations and slow population momentum. Population policies will be more effective when human rights are protected.     

Cohort Differences in Parental Financial Help to Adult Children

In this article, we examine birth cohort differences in parents’ provision of monetary help to adult children with particular focus on the extent to which cohort differences in family structure and the transition to adulthood influence these changes. Using data from the Health and Retirement Study from 1994 to 2010, we compare financial help to children of three respondent cohorts as the parents in these birth cohorts from ages 53–58 to 57–62. We find that transfers to children have increased among more recent cohorts. Two trends—declining family size and children’s delay in marriage—account for part of the increase across cohorts. However, other trends, such as the increase in the number of stepchildren and increasing child’s income level, tend to decrease the observed cohort trend.     

On the tempo of childbearing in England and Wales

Abstract The paper describes a computerized model developed to simulate the fertility of a hypothetical marriage cohort in a closed population. The model was applied to England and Wales fertility data of marriage cohorts of the years 1951 to 1970. For each of these cohorts, the computer was programmed to construct five series of tables showing birth-order probabilities, family size frequency distribution, mean length of intervals between marriage and successive births, parity progression ratios and mean family sizes of fertile women. The results showed that the fertility of the cohorts of women who married between the middle 1950s and the early 1960s was character ized by a declining trend in the frequency of childlessness and by a dramatic increase in the proportion of marriages with two or more children. Since 1964 or so, there has been a downward trend in duration-specific birth-order probabilities. The analysis suggests that the recent drop in fertility may well prove to be the effect of an upward shift in the timing of births as well as a fall in completed fertility.     

A demographic perspective on the Muslim world

A demographic perspective is relevant to understanding the position of Muslims in today’s world. This paper examines the size and growth of Muslim populations, and whether most Muslims live in overwhelmingly Muslim countries. It also examines indices of poverty and human development for Muslimmajority countries, and the growth of the youth population; finally, it examines the key components of population growth: mortality and fertility. Mortality has declined sharply over the past 15 years in many Muslim countries, though not in all, and Muslim countries are no longer prominent among the ‘outliers’ with higher mortality than expected on the basis of their income levels. Fertility rates are also declining sharply in a number of major Muslim-majority countries, raising interesting issues about attitudes of different schools of Islamic jurisprudence, village-level religious leaders and ordinary Muslims towards contraception and abortion, as well as the role of socio-economic development and family planning programs in fertility declines. Despite these declines, past high fertility in many Muslim-majority countries leaves as a legacy a rapidly growing adolescent population and a burgeoning, inadequately educated labour force.     

A fertility survey in the Maltese Islands

In order to determine whether fertility is declining in Malta, a sample was taken by the Maltese Central Statistical Office in mid-1955, along the line of the Family Census of 1946 in Great Britain. The size of the sample was 10,000, and the response very good. The sample shows no noticeable decline in fertility since the marriage cohorts of the beginning of the century. Some decline is noticeable int he fertility of the later durations of marriage, but completed family size remained more than 6 for the cohorts of the 1920's. This contrasts with the declining fertility shown by the enquiry in Great Britain, and the figure of 6 is in fact much greater than the completed families born to cohorts in Great Britain at the end of Queen Victoria's reign. Fertility seems in fact to be still rising in Malta for the first 18 months of marriage; and the first decade of marriage continues to show an average of 4 births. It seems therefore that the recent decline in the birth rate is to be attributed to changes in the populatino structure rather than in marital fertility. The continued high fertility implies a very rapid rise in population in the absence of emigration.     

Sub-Saharan Africa: population pressures on development

The population of sub-Saharan Africa, estimated at 434 million in 1984, is expected to reach 1.4 billion by 2025. The birth rate, currently 48/1000 population, continues to increase, and the death rate, 17/1000, is declining. Rapid population growth has curtailed government efforts to provide adequate nutrition, preserve the land base essential for future development, meet the demand for jobs, education, and health services, and address overcrowding in urban areas. Low education, rural residence, and low incomes are key contributors to the area's high fertility. Other factors include women's restricted roles, early age at marriage, a need for children as a source of security and support in old age, and limited knowledge of and access to modern methods of contraception. Average desired family size, which is higher than actual family size in most countries, is 6-9 children. Although government leaders have expressed ambivalence toward development of population policies and family planning programs as a result of the identification of such programs with Western aid donors, the policy climat is gradually changing. By mid-1984, at least 13 of the 42 countries in the region had indicated that they consider current fertility rates too high and support government and/or private family planning programs to reduce fertility. In addition, 26 countries in the region provide some government family planning services, usually integrated with maternal and child health programs. However, 10 countries in the region do not support family planning services for any reason. Unfortunately, sub-Saharan Africa has not yet produced a family planning program with a measurable effect on fertility that could serve as a model for other countries in the region. Social and economic change is central to any hope of fertility reduction in sub-Saharan Africa. Lower infant and child mortality rates, rising incomes, higher education, greater economic and social opportunities for women, and increased security would provide a climate more conducive to fertility decline. Given the limited demand, great sensitivity must be shown in implementing family planning programs.     

A model of voluntary childlessness

Demographers and sociologists have studied why women remain childless for more than two decades; however, this specific choice of zero fertility has not interested economists. Permanent childlessness, in developed countries, can concern up to 30 % of the women in a cohort. Childlessness rates can be positively related to average fertility for some cohorts of women. This paper provides an explanation for this using an endogenous fertility model where individuals have different preferences for children. The main mechanism considered goes through the intergenerational evolution of preferences: I show that a reduction in the gender wage gap, or an increase in the fixed cost of becoming a parent, has a negative effect on both fertility and childlessness. The reduction of childlessness is due to a composition effect: small families shrink more than larger families, and this reduces childlessness.     

Completing the Demographic Transition

Despite ongoing declines in fertility in many countries, the population of the world is experiencing a period of rapid expansion, and its size is expected to reach 10 billion by the end of the demographic transition. Three causes of this growth are identified and quantified: 1) fertility above the replacement level of two surviving children per woman, 2) continuing declines in mortality, and 3) population momentum resulting from a young age structure. A set of simple analytic expressions is proposed for estimating these factors from standard demographic indicators. Population momentum is shown to be the main cause of future growth in most countries and regions.     

The World Fertility Survey: charting global childbearing

Interviewing some 350,000 women in 42 developing countries and 20 developed countries representing nearly 40% of the world's population, the World Fertility Survey (WFS) is in a unique position to document the historic 1970s slowdown in global population growth. This Bulletin describes efforts begun in 1972 to ensure high quality, internationally comparable, accessible data, the data's importance for policymakers, planners and researchers, and major findings available by early 1982 from directly assisted WFS surveys in 29 developing countries and contraceptive use data from WFS-type surveys in 16 developed countries. Marital fertility has declined in all developing regions except Africa but still averages from 4.6 children/woman in Latin America to 6.7 in Africa, while preferred family size ranges from 3.0 children in Turkey to 8.9 in Senegal--far above the average 2.2-2.5 children/woman needed to end developing countries' population growth in the long run. However, women ages 15-19 prefer nearly 2 children fewer than the oldest women ages 45-49; 3.8 vs. 5.7 on the average. Nearly 1/2 (48%) of married women surveyed in 27 countreis said they wanted no more children. Preventing all unwanted births would reduce birth rates up to 15 births/1000 population in these countries. Overall, 32% of married, fecund women in developing countries are using contraception compared to an average 72% in 16 developed countries. Education, literacy, and more available family planning services increase contraceptive use. Age at marriage is rising in Asia, but this factor alone has little effect on fertility. Infant mortality is higher in many developing countries than previously thought. Breastfeeding is an important restraint on fertility in most developing countries but is declining among more educated, employed, and urban women which could raise fertility if not compensated for by gains in contraceptive use.     

The changing relationship between family size and educational attainment over the course of socioeconomic development: Evidence from Indonesia

Many studies from developed countries show a negative correlation between family size and children’s schooling, while results from developing countries show this association ranging from positive to neutral to negative, depending on the context. The body of evidence suggests that this relationship changes as a society develops, but this theory has been difficult to assess because the existing evidence requires comparisons across countries with different social structures and at different levels of development. The world’s fourth most populous nation in 2007, Indonesia has developed rapidly in recent decades. This context provides the opportunity to study these relationships within the same rapidly developing setting to see if and how these associations change. Results show that in urban areas, the association between family size and children’s schooling was positive for older cohorts but negative for more recent cohorts. Models using instrumental variables to address the potential endogeneity of fertility con rm these results. In contrast, rural areas show no significant association between family size and children’s schooling for any cohort. These findings show how the relationship between family size and children’s schooling can differ within the same country and change over time as contextual factors evolve with socioeconomic development.     

The Middle East population puzzle

An overview is provided of Middle Eastern countries on the following topics; population change, epidemiological transition theory and 4 patterns of transition in the middle East, transition in causes of death, infant mortality declines, war mortality, fertility, family planning, age and sex composition, ethnicity, educational status, urbanization, labor force, international labor migration, refugees, Jewish immigration, families, marriage patterns, and future growth. The Middle East is geographically defined as Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen, Gaza and the West Bank, Iran, Turkey, and Israel. The Middle East's population grew very little until 1990 when the population was 43 million. Population was about doubled in the mid-1950s at 80 million. Rapid growth occurred after 1950 with declines in mortality due to widespread disease control and sanitation efforts. Countries are grouped in the following ways: persistent high fertility and declining mortality with low to medium socioeconomic conditions (Jordan, Oman, Syria, Yemen, and the West Bank and Gaza), declining fertility and mortality in intermediate socioeconomic development (Egypt, Lebanon, Turkey, and Iran), high fertility and declining mortality in high socioeconomic conditions (Bahrain, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), and low fertility and mortality in average socioeconomic conditions (Israel). As birth and death rates decline, there is an accompanying shift from communicable diseases to degenerative diseases and increases in life expectancy; this pattern is reflected in the available data from Egypt, Kuwait, and Israel. High infant and child mortality tends to remain a problem throughout the Middle East, with the exception of Israel and the Gulf States. War casualties are undetermined, yet have not impeded the fastest growing population growth rate in the world. The average fertility is 5 births/woman by the age of 45. Muslim countries tend to have larger families. Contraceptive use is low in the region, with the exception of Turkey and Egypt and among urban and educated populations. More than 40% of the population is under 15 years of age. The region is about 50% Arabic (140 million). Educational status has increased, particularly for men; the lowest literacy rates for women are in Yemen and Egypt. The largest countries are Iran, Turkey, and Egypt.     

Costs and benefits of children: implications for population policy

Family size preferences are strongly affected by parents' perceptions of the value, economic contributions, and costs of children. Better understanding of these factors can help policy-makers to improve the effectiveness of population IEC campaigns, design strategies to persuade couples to have smaller families, assess the relationship between economic development and family size preferences, and devise national population policies and family planning programs that reflect individual choices. Parents in high-fertility countries are more likely to perceive children as productive investments than those in low-fertility countries. Parents in the former countries maintain children are an economic advantage or provide practical assistance in the household; they are less likely to emphasize the psychological advantages of children. As economic development occurs, and parents no longer value children for their economic contributions, psychological and social reasons become more important. Changing fertility preferences is more complex than providing couples with family planning services. Similarly, efforts to persuade families that large families are a burden are successful only when families are already interested in reducing their family size. Efforts to persuade couples to have smaller families are likely to be more successful if there are alternative sources of old-age support available, for example, from increased household savings, public or private pensions, or greater contributions from 1st and 2nd children. Investments in education and training, especially for women and children, would also support these goals.     

World population in transition

The world's population growth rate peaked at slightly over 2%/year in the late 1960s and in 1986 is down to 1.7% and falling. Annual numbers added continue to rise because these rates apply to a very large base, 4.9 billion in 1986. According to UN medium variant projections, world population growth will peak at 89 million/year in the late 1990s and then taper off until world population stabilizes in the late decade of the 21st century at about 10.2 billion. Close to 95% of this growth is occurring in less developed countries (LDCs) of Africa, Asia (minus Japan), and Latin America. LDC fertility rates are declining, except in sub-Saharan Africa and parts of Latin America and South Asia, but most have far to go to reach the replacement level of 2.1 births/woman. Fertility is below replacement in virtually all more developed countries. For LDCs, large numbers will be added before stabilization even after attainment of replacement level fertility because of the demographic momentum built into their large and young population bases. This complicates efforts to bridge gaps between living standards in LDCs and industrialized countries. From a new debate about whether rapid population growth deters or stimulates economic growth, a more integrated view has emerged. This view recognizes the complementary relationship between efforts to slow population growth and other development efforts; e.g., to improve health and education, upgrade women's status, increase productivity. Most effective in the increased contraceptive prevalence and fertility declines seen in many LDCs has been the combination of organized programs to increase access to family planning information and supplies with socioeconomic development that enhances the desire for smaller families.     

Family sizes of children and family sizes of women

This paper demonstrates the relation that obtains between the average family size of women and the average family size of offspring of those women. It estimates the value of these two measures for cohorts of American women aged 45–49 in various years from 1890 to 1970. It shows that children born during the post-war baby boom actually derived from smaller families than those born during the low-fertility 1930’s; that under current patterns a woman would have to bear an average of almost two children fewer than were borne by her mother merely to keep population fertility rates constant from generation to generation; and that average family size for nonwhite children exceeds that for white by 50 percent, although the racial difference in family sizes of women is only 19 percent.     

A fertility analysis of New Zealand marriage cohorts

New Zealand annual returns of non-Maori live legitimate births 1913 to 1955 were tabulated longitudinally by marriage duration and birth order. The figures were used as numerators of fertility rates of forty marriage cohorts, specific for duration and birth order ; the twenty-four oldest cohorts had virtually completed fertility. For the denominators of the rates, the cohorts of initial size (estimated by a method similar to that described by P. H. Karmel) were survived by observing changes over time through divorce, death, widowhood, war-widowhood, and net external migration. The aim was to provide a set of data of the best possible approximation on variations of cohort fertility.

Total cohort rates, cumulated for twenty years’ duration of marriage, and segmental rates of relevant sub-periods are given for parities o to 7+. Total rates of the cohorts of completed fertility yielded values of family size, and were also used for parity progression ratios (by L. Henry’s formula). Segmental rates permitted a study of changes in timing maternities.

The analysis, which needs as a corollary a nuptiality analysis, is concerned, so far with past experience. It confirms the decline in number and proportion of large families. Both the parity progression ratios, and segmental rates of cohorts of as yet incomplete fertility, suggest some recent recovery in three- and fourchild families. For total fertility, such recovery might even be more significant than the observed decline in large families. On the other hand, birth-order specific changes in timing suggest lengthening of intervals among older cohorts as a trend upon which is superimposed the fluctuation due to postponement of, and recovery of a portion of postponed maternities. A construction of hypothetical timing patterns for incomplete cohorts by a simplified method of projection does not lead very far without support of observations on spacing that differentiate for family size.