High Fertility Population Research Articles

Population growth and the birth squeeze

Birth squeezes result from an imbalance in the number of males and females in the childbearing ages, and can have a significant impact on the level and distribution of births. To measure the effects of a birth squeeze, the observed male and female age-specific birth rates were distinguished from the underlying fertility magnitudes, which reflect the mutual propensity of males and females of specified ages to have a child. The fertility magnitudes, readily expressible in terms of the birth rates, are nonetheless independent of the age-sex composition of the population, while the birth rates are affected by compositional changes. The two-sex Total Fertility Rate, TFR2, the average of the male and female TFRs, is advanced as a summary measure of fertility independent of the birth squeeze, and a simple index, U, is defined to measure the severity of the squeeze. Analyses involving stable population models, alternative population projections, and the birth squeezes found in contemporary populations documented the importance of the birth squeeze for studies of fertility. In particular, the size of the distortions introduced by the birth squeeze was seen as related to the level of fertility itself. In high-fertility populations, the birth squeeze depresses observed female age-specific birth rates, and thus conventional measures can significantly underestimate the fertility reduction needed to end population growth.

The Onset of Fertility Transition

For many years it has been known that in virtually no human population has the level of fertility ever approached the potential biological maximum. Scholars have long been aware that such factors as constraints on marriage, prolonged breastfeeding, periods of separation or abstinence, abortion, and disease have exerted a restraining influence on fertility. Thus while systematic investigation of the relationships determining fertility levels had to await the work of researchers such as Kingsley Davis and Judith Blake, and John Bongaarts, ' the seeds of two basic ideas-first that the prevailing level of fertility is the outcome of a balance of factors, and second that even in a high-fertility population birth rates could possibly risehave long been germinating. Confronted with the beginnings of widespread rapid population growth in developing countries during the 1930s and 1940s, demographers such as Kingsley Davis, Warren Thompson, Frank Lorimer, and Frank Notestein naturally initially identified the cause of faster growth as improvements in mortality. Although they recognized the two aforementioned ideas, in those early days there was no evidence to suggest that there had been any rise in fertility, whereas there were good reasons for thinking that death rates had declined.2 Moreover, the view that rapid population growth resulted from mortality decline in the presence of high and more or less stable birth rates was consistent with the main descriptive and theoretical statements contained in the early writings on demographic transition theory, of which these scholars were key formulators. In the 1960s, however, there emerged a significant qualification to earlier views. While improvements in mortality were still seen as the primary cause of the acceleration in growth, several writers now maintained that the role of

Age-at-Family Formation and Family Size: A Cross-Cultural Comparison

Demographers suggest that as the less developed societies become modernized, the direction and effect of the determinants of fertility in these societies will become similar to that of the developed societies. This study explores the net influence of age-at-family formation on family size among two high fertility populations in two different social contexts : one a developed setting (Racine in Wisconsin) and the other a developing setting (city of Ahmedabad in India). Age-at-family formation has a strong negative effect on completed family size. The effect is found to be stronger in the case of the population in Racine. For explaining the cross-cultural differences in fertility, the differences in the decision making process related to fertility may be more important than mere structural changes such urbanization and industrialization resulting in similar mean age-at-family formation.

Population Growth May Be Good for LDCs in the Long Run: A Richer Simulation Model

This paper reexamines the theory that high fertility and positive population growth exert a negative effect on output/worker and income/consumer equivalent. A model is constructed that includes all the elements found in other models of population growth in less developed countries (e.g. diminishing returns effect of dependency) but also incorporates other elements such as demand and its effect on investment the shift of labor from agriculture to industry the work-leisure choice and economies of scale. In addition the model substitutes an accelerator investment function for the constant proportion of output function used in other models. The simulation indicates that moderate population growth produces considerably better economic performance in the long-run (120-80 years) than slower population growth although a stationary population perform slightly better in the short-run (60 years). Estimates of the parameters for a representative Asian less developed country suggest that moderate population growth (doubling over 50 years) performs better in the long-run than either fast population growth (doubling over 35 years or less) or slow population growth (doubling over 200 years). The importance of this model rests in its finding that there are some sets of conditions under which fairly high fertility gives better economic performance at some times than low fertility while the opposite is the case under other sets of conditions. Since different parameters produce different rates of optimum population growth no 1 fertility structure can be assumed to be unconditionally better than another. Finally these results imply that a more complex quantitatively based theory of population growth is required.

On the analysis of family continuation probabilities which are composition-specific

A technique is proposed for ascertaining a population's preference for certain combinations of sons and daughters on the basis of actual fertility behavior. For completed families, we work with the probability of continuing to a higher parity given a particular combination of sons and daughters, which is independent of Lexian or other variation in the sex ratio at birth. Multiplicative models are applied to these probabilities. An illustration of these models is given for a high fertility population which shows no evidence of any kind of sex-related preference.

Recent fertility declines in Hong Kong: the role of the changing age structure

Abstract The birth rate in Hong Kong fell rapidly from 1961 to 1966: from 35·5 in 1961 to 25·8 in 1966 1 These rates are based on corrected estimates of population and of births made after the 1966 census. They differ somewhat from rates published before that, because the earlier rates had not been adjusted for some underregistration of births and had been calculated on larger population bases than proved to be justified by the census. - a decline of27%. Such a decline deserves special attention, because there are only a few examples of such trends in poor, high-fertility populations since World War II. We have just begun to find evidence of such declines in a few of the other rapidly developing countries of Asia: Taiwan, Korea, Singapore, and Malaysia.

Interrelationships of Some Fertility Measures in Pakistan

Unlike mortality or migration, the fertility behaviour of a population largely determines its age distribution1. A high fertility population maintains a broad-based age pyramid by adding continuously a large number of persons at the first year of life. In such a population the dependency ratio of children (say persons under 15 years) remains high relative to the size of its working age population (say those aged 15-64 years). A decline in fertility reduces this ratio and restructures the age distribution to make it more favourable to economic growth2 [4]. For this reason the study of human fertility occupies a singularly important position in the demographic literature today. In this paper the fertility of the population of Pakistan is examined. The purpose of the paper is to evaluate several fertility measures obtained from data collected through the Population Growth Estimation project in Pakistan3. The interrelationships of these measures in terms of their practical utility to planners for action programmes will be examined. Further, the possible impact on fertility resulting from a rise in the age at marriage in Pakistan will be discussed. An effort will also be made to identify the demographic differentials, relevant to planners, in the two provinces of the country

The decline of fertility: Innovation or adjustment process

Abstract In Western society the process of fertility decline is often regarded as an innovation process. The assumptions behind this approach seem rather questionable, and the diffusion lags or gradients of limited importance. Both Swedish and other European data are used as illustrations. It is suggested that the decline be treated within the wider sociological perspective of a time-consuming adjustment or change process, not necessarily starting from a position of completely uncontrolled fertility within marriage. The situation in to-day's high fertility populations is briefly discussed against this background.

The Significance of Age-Patterns of Fertility in High Fertility Populations

Information on perception of family planning and reactions to it in a Kwahu matrilineage in Ghana is based upon 3 6-month periods of fieldwork. The attempt is made to relate both perception and practice of birth control to some structural aspects of conjugal and sexual behavior in the lineage concerned. The population of this survey is 2 main sections of 1 matrilineage consisting of about 75 living adults 60 of whom are either women in their childbearing years or mean younger than 65. Due to a wide geographical dispersion only 38 of the 60 were interviewed along with 4 people closely related to the lineage by paternal descent or affinity. On the basis of the interviews it appears that perception of family planning and subsequent reaction to it is associated to a very specific conjugal situation in the lineage. The low status and instability of customary marriage the high incidence of premarital and extramarital relations and the matrifocal quality of most sexual unions have contributed to the following: 1) irreversible methods of birth control will be difficult to accept; 2) birth control is essentially practiced outside of marriage and consequently associated with secretive practices; and 3) the practice of birth control will essentially depend on the decision of the woman. The practice of birth control is an entirely new phenomenon in the lineage and still basically limited to the younger generation. Ghanas present family planning effort remains unaware that a sizable group in need of contraceptives are in no position to identify with their promoted image of a small planned nuclear family. Additionally it is unreasonable of the program to deny contraception to those individuals who are unmarried. (AUTHORS MODIFIED)