Norman B. Ryder

The process of demographic translation

Resumen“Traslación demográfica” es el establecimiento de interrelaciones entre una serie cronológica de observaciones en sección transversal en períodos de tiempo sucesivos y las series cronológicas del mismo indice, referido. a cohortes sucesivas. Este documento presenta dos tipos de soluciones a este problema y dá algunos ejemplos de cada uno.

Use of oral contraception in the United States 1965.

This is the first report from the Na-tional Fertility Study, 1965, a survey of the reproductive behavior of a national sample of married women, under the age of 55, living with their husbands. The report presents basic data on the use of oral contraception by women under the age of 45, in relation to age, parity, education, race, and religion. The study leads to certain conclusions, as follows. Present, past, and prospective use vary inversely with the age of the woman and directly with the number of years of schooling; the majority of young women with college training have already used the oral contraceptive. Use by Negroes is somewhat less extensive than use by whites, particularly for ages below 25; some of this difference is explainable by concomitant racial differences in educational level. Negroes seem less likely than whites to use oral contraception for timing early births, and more likely, when they do use it, to be attempting to terminate their fertility. The same observation holds for white Catholics in relation to white non-Catholics. Although the extent of use may be lower among Catholics than non-Catholics, the proportion of Catholics who report use is substantial indeed in view of the persisting theological controversy. The prospects for increased use of oral contraception seem very good at present, but they may be limited by further developments in the technology of fertility regulation. Meanwhile the birth rate has declined substantially. Although much sophisticated analysis of other data from the survey will be required to determine the extent of the contribution of oral contraception to this decline, the findings presented here suggest that the contribution is substantial for young married couples. The major effect on the couples eventual number of children may be less than the effect on the time pattern of childbearing; in any event, both lower eventual parity and delayed fertility contribute to a decline in the numbers of births from year to year. Whatever the intent may be, it is apparent that young American couples have adopted a new means for achieving their reproductive goals.

Oral contraception, coital frequency, and the time required to conceive

Using data from the 1965 National Fertility Study (NFS) and from the 1957-1967 Princeton Fertility Study (PFS) the relationship between oral contraceptive use coital frequency and time required for conception is studied. Using NFS data mean monthly coital frequency (calculated by contraceptive method for women classified by age race education and religion) for women aged 25-44 was increased 18-20% for pill users compared to those using other methods a finding consistent with the PFS which observed a 7.5 monthly frequency rate for pill users compared to a theoretical 6.3 rate had they not shifted to pill use. Using data confined to women of similar age who discontinued contraception between June 1961 and September 1965 in order to conceive and adjusting coital frequency by age no difference was found in the time required to conceive between women who have used the pill and women who have used other methods of contraception. 85-87% of all women were pregnant within the first 6 months with a mean waiting time of 2.1-2.3 months; similar knowledge of the ovulatory cycle was found for both groups. Limitations to study results including reliability of measurement of coital frequency and problems of selectivity including age and memory bias are discussed.

Fertility planning status: united states, 1965

Data concerning the planning circumstances of the interval preceding each pregnancy, collected from a national sample of 4810 married women, are used to establish the fertility planning status of each respondent as one of five classes: (1) never-pregnant; (2) number failure; (3) at least one timing failure; (4) at least one timing success; (5) neither success nor failure. For the ever-pregnant women who intended no more children, 32 percent of the exposed were number failures and 62 percent of the rest were timing failures. For the ever-pregnant women who intended more children, 67 percent of the exposed were timing failures. Women not exposed to the risk of timing failure because they claimed to want all of their pregnancies as soon as possible had similar characteristics to women reporting failures; accordingly the reliability of their reports is suspect. The probabilities of failure are well-patterned by race, religion and education: higher for Blacks than for Whites; within the latter, higher for Catholics than for Non-Catholics; and inversely related to education, except among White Catholics. Although uniformly high, the proportions classified as failures are probably under-estimates of the true values for completed families, because of misreporting and continuing exposure to risk, subsequent to interview.

The Character of Modern Fertility

One characteristic shared by all modern indus trialized and urbanized nations is low fertility. From different initial levels, beginning at different times, the birth rates have declined slowly in some industrialized and urbanized countries and rapidly in others, but have now settled down on a common low plateau a little above what is required for replacement. The regulation of fertility has been achieved by widely variant strategies, involving different combinations of nuptiality control, contraception, and abortion. In every case the small family size has represented the intent of the individual couple and not the guidance of government or church. The explanation of fertility decline advanced here places stress on a normative change in the relationship between parents and children under conditions of declining mortality and urban economic development. Although the fertility of modern industrialized and urbanized nations is not expected to change much in the long run, these societies will probably have difficulty in avoiding costly fertility fluctuations and in keeping the reproductive goals of individual couples from eventuating in too little or too much population growth.

The Reproductive Renaissance North of the Rio Grande

The annual numbers of births in the United States and in Canada have increased by more than 70 per cent in the past twenty years. In both countries an important component of this increase has been a change in the timing pattern of births. In addition to the spurious inflation of annual fer tility which such a timing change induces, mean parity for American cohorts has increased by 27 per cent because of a decline in the proportion of women with submodal fertility. The most likely explanation of this is a rise in real per- capita income among those who regulate childbearing.

Fertility and population regulation

Abstract Using data from two sample survey studies of fertility in the United States, the authors report that the mean coital frequency of women taking the pill exceeds the average for women using all other contraceptive methods. However, in time to conception, the data indicate that when all factors are taken into account there is no difference in the time required to conceive between women who had previously used the pill and those who had used other methods of contraception.

The Demographer and His World

Of all the problems which face mankind today, perhaps the greatest is the so-called ‘population explosion’. Over large areas of the world populations are now growing faster than ever before. Often these areas are the poorest, either because they have few resources or lack the capital and knowledge to exploit them. Often too they have political and social systems that appear quite inappropriate to deal with the variety of problems associated with rapid population growth. In this situation, what can the social scientist offer? At first glance the answer might appear to be — not very much. In fact, however, the social scientist can offer a greater understanding of what is involved in the problems associated with population growth. He can define them more precisely, clarify the issues and so lay the foundations for more enlightened policy.