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This paper introduces the concept of the ‘age-profile’, which represents the proportions of cohort populations surviving from birth to a given year. Life tables for Australia and three-dimensional diagrams based on these data are used to illustrate the difference between the ‘age-profile’ values for a given year and the transverse survival values for the same year. The last part of the paper describes areas in which the ‘age-profile’ might be used with reference to its value in representing the experience of cohorts. [ABSTRACT FROM PUBLISHER]

In a previous paper a formula was derived from which the total fertility rate of a group of women could be estimated from the average number of live births to women in the reproductive period. In the present paper the argument is carried further and a method is given by which the total fertility rate may be estimated from the average number of children born to fertile women during the reproductive period. The method given in this paper may, under certain circumstances, have considerable advantages over the previous method suggested. [ABSTRACT FROM AUTHOR]

The duration of time between two successive births or between marriage and first birth is an indicator of the level of fertility of a couple. Potter and Parker (1964) and Singh (1961, 1967) have suggested the Type I Geometric as a distribution appropriate Or representing the length of interval to first conception leading to a live birth. Potter and Parker estimated the parameters of this distribution with the help of the first two moments. Majumdar and Sheps (1970) pointed out the limitations of these moment estimates and gave a method to Obtain maximum likelihood estimates, based on formulas which are too involved for solution without the help of a computer. Singh proposed a continuous probability distribution based on another set of assumptions for the above situation. He outlined a method to obtain best asymptotically normal estimates of the parameters. These estimates are obtained after several iterations starting from any set of consistent estimates. The objective of this paper is to show that it is relatively easier to obtain maximum likelihood estimates of the parameters of the continuous model, which describes the data on duration to first conception as well as does the discrete model. Simple expressions for the moment and maximum likelihood estimates with the corresponding covariance matrices are obtained. Application is made to three sets of data. [ABSTRACT FROM AUTHOR]

The computation of births averted due to a specific family plane fling programme requires special treatment instead of application of the usual population projection technique using conventional fertility rates. The reason for this is that adopters of a family planning method are a selective group from the general population with respect to a number of demographic and biological characteristics, including the initial susceptibility status at the time of adoption. In the present paper a matrix of annual birth probabilities specific to age at adoption of a method and duration since adoption is obtained, One matrix is presented for adopters of IUCD, another for salpingectomy, and a third for vasectomy. These matrices are used to obtain estimates of births averted for India due to IUCDs and sterilizations performed during 1956-69. The results are com- pared with those that could have been obtained by using the usual age- specific marital fertility rates under identical conditions, except for initial susceptibility. The entire work is programmed on a high speed electronic computer. [ABSTRACT FROM AUTHOR]

This paper presents seasonal patterns of conception in New York City and discusses the implications of these patterns. It is intended to investigate variations by month of conception of factors associated with pregnancy. [ABSTRACT FROM AUTHOR]

Fetal wastage and involuntary delays of conception combine to limit the precision with which birth intervals may be planned. In this paper a waiting-time model is used to estimate the expected time to conception following specified past delays of conception. It is assumed that a couple's monthly chance of conception, or fecundability, remains constant while, among couples, fecundability varies as a Pearson Type I curve. The model is applied with reference to three questions. First, knowing the duration of their infertility, what can a couple surmise about the likelihood of being sterile, or, if not sterile, about the additional months they will have to wait for a first conception? Second, among mothers wanting to plan a second conception, how valid is the premise that the time required for this next conception will be about as long as that required for the first? Third, in what manner does a previous history of abortion modify a mother's expectation concerning the time required for a live birth after discontinuing contraception? By assuming that the monthly chance of conception in the absence of contraception, hereafter termed fecundability, varies among couples but remains constant from month to month until Pregnancy for individual couples, one is able to treat conceptive delays as a waiting-time problem. It is the purpose of this paper to present a waiting time model, which, together with assumptions about pregnancy wastage, furnishes some preliminary answers to the questions, posed above.

The paper explains why so many people exercising freedom of choice and living in a world of privatized religion, elect to make use of religious rites of passage, in the form of religious rituals associated with birth, marriage and death, while at the same time rejecting other social forms of religious action. The phenomenon is a complex one and therefore any simple causal explanation will probably be inadequate. Moreover, the undergirding of rites has changed with the course of time, no longer are they upheld by legal or quasi-legal sanctions. Recognition has to be given to the social setting of rites of passage. A crucial mark of differentiation between rites of passage and other rituals is that such rites directly involve, or are intended to involve, family and kin groups, extending even to the local community, that is, participants stand in a socially structured situation. Rites have some religious significance for participants. To actors, occasions related to rites of passage, the birth of a child, marriage and death, are in themselves times of personal importance, although not necessarily of crisis proportions.

The steady increase in the annual number of illegitimate births since 1940 has led to a widespread public concern for the causes and consequences of illegitimacy. Trends and differentials in the incidence of illegitimacy since 1940 are described in this paper. The analysis is based principally on the illegitimacy rate, which is the number of illegitimate births per 1,000 unmarried women 15-44 years of age. This measure is particularly useful because it relates illegitimate births to the population at risk. All of the measures indicate that the prevalence of illegitimacy has increased over the past 26 years, but there have been several distinct intervals in this period. The illegitimacy rate, for example, nearly doubled from 1940 (7.1) to 1950 (14.1). The rate continued to rise rapidly until 1957 (21.0); since then it has risen only slightly and now appears to be declining. By 1966, the rate was 23.4, or only 11 percent higher than in 1957. The differences in illegitimacy between the white and nonwhite population are wide. Although the measures of illegitimacy have always been higher for the nonwhite than for the white population, this differential has been declining in recent years. Other important differentials in illegitimacy can be seen when the births are classified by age of mother and live-birth order. Socioeconomic status is considered an important factor in accounting for differentials in illegitimacy. Our inability to account satisfactorily for the increasing prevalence of illegitimacy or for the differentials in illegitimacy clearly demonstrates the need for more research. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to evaluate the accuracy of Zipf's hypothesis in estimating interstate migration streams in the United States, and then to determine whether the predictive power of Zipf's hypothesis can be improved by adding additional variables. The three independent variables in Zipf's hypothesis accounted for 57 percent of the variation in interstate migration streams in 1935-1940, 61 percent in 1949-1950, and 68 percent in 1955-1960. The addition of per capita personal income of the states of origin and of destination increased the explained variance by only four percentage points in 1935-1940 and by less than one percentage point in 1949-1950 and 1955-1960. Then, the Petersen-Greenwood hypothesis that interstate migration streams in any period are a function of previous flows was tested by adding cumulative lifetime migration as an independent variable. Over 80 percent of the variation in interstate migration streams was explained by cumulative lifetime mobility, as reflected by state of birth data. The conclusion of the study is that the Petersen-Greenwood hypothesis provides a better estimate of interstate migration streams than does Zipf's hypothesis. Nevertheless, the Petersen-Greenwood hypothesis requires further evaluation to determine whether cumulative lifetime mobility is simply a proxy for some other underlying variable and whether it provides accurate estimates of migration streams for other geographic areas. [ABSTRACT FROM AUTHOR]

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The purpose of this paper is: (1) to test, in two additional states, the applicability of a method devised by Ciocco in studying ‘intercounty movements’ relative to live births and to suggest some possible refinements to his method, and (2) to delineate certain ‘medical areas’ in these two states on the basis of the findings. In order to investigate these phenomena, the live births in each Michigan and Missouri county during 1952 were divided into two components—‘In-Residence’ and ‘Out-Residence’ births. Some possible explanations of variation of the ‘In-Residence’ ratios among the different counties ere examined in relation to three independent variables: (1) number of hospital beds per 1,000 population, (2) number of physicians relative to population, and (3) median family income. Ciocco's method is found to have some usefulness; but it is shown that each state should be examined separately, and other factors should be considered. [ABSTRACT FROM AUTHOR]

In this paper, the authors attempt to add to their store of knowledge concerning population growth by estimating a simultaneous equation model of birth rates in the United States. Their model is based on time-series data for the United States covering the 1910 to 1968 period and consists of four separate equations: a birth rate equation, a permanent income equation, an infant mortality equation, and a female labor participation rate equation. Two variants of the total model are reported. The first is based on the two-stage regression procedure and the second variant is based on three-stage least squares. In both cases, elasticity multipliers are computed as a guide to policy decision making. In general, the two approaches yield quite similar results; nevertheless, there are some differences - therefore, the dual approach is given. The data are generally unadjusted and should therefore reflect both secular and cyclical patterns. The major exception to this rule is our use of permanent rather than measured income for reasons outlined in the paper.

Birth order (ordinal position) in the nuclear family has been found to be related to a large number of social and psychological factors. Yet the reasons why are not clear. The literature on birth order reflects considerable theoretical confusion. It appears that researchers often discover the significance of birth order accidentally while engaged in other research. As a result their theorizing tends to be frost hoc and to have a disconnected character. There is a need for some system which will aid in the evaluation of existing research findings, and indicate strategic areas for future research. Such a system is introduced, along with some suggestions for research. [ABSTRACT FROM AUTHOR]

The article presents a review of American studies about the physical growth of white children. It focuses on studies concerned with the growth in external bodily dimensions of physically normal human subjects, on research conducted on American white children from birth to eighteen year of age, and on those which were published by its contributors before 1900. The studies reviewed include Samuel Henry Dickson's research on stature and body weight in 1858, Joseph K. T. Van Pelt's study on the maximum diameters of head at birth, and Etienne Evetzky's paper on birth weight of infants and their growth in body weight.

Open live birth intervals have been suggested by some authors as a measure of fertility change, brought about by contraception, especially in the context of developing countries. But some researches made in the past few years have brought out a number of problems that limit the usefulness of the open live birth interval as an indicator of fertility change. In the present paper a computer model (expected values model) has been used to study two problems that arise in the use of open live birth intervals: (i) the dependence of the open live birth interval on age and parity of women and the effect of adjustments such as standardization on open birth intervals, and (ii) the inability of the open birth interval to indicate changing fertility under continuous and long term contraception as against short term contraception. [ABSTRACT FROM AUTHOR]

The article analysis short-run variations in marital fertility in Sweden during the period 1830-1879 in order to explore different models of fertility determination before the secular decline of fertility took place, and to use fertility data to demonstrate a method of studying sociological trends and oscillations. One of the main determinants of aggregate marital fertility, the total number of legitimate births or the legitimate birth rate, is the number of marriages, and fluctuations in that number. It will be shown that if this were the sole determinant the result would be a very high degree of smoothness in the response, fertility. Auto-correlations would be high, much higher than actually observed. So a simple inspection of the response series and the correlogram is sufficient to reject this explanation, even if there were no direct statistical information on the annual number of marriages. But as direct information on marriages is available, this may be used to compute the expected level of aggregate marital fertility assuming a constant fertility schedule by duration of marriage. This turns out to follow the smooth pattern predicted, whilst observed fertility shows much more pronounced short-term variations.

The paper deals with the extremely high birth rate of Roman Catholics in the Netherlands, a rate which is considerably higher than that of Catholics in other countries living under similar circumstances. The fertility of Catholics living on either side of the Dutch-Belgian and Dutch-German frontier was analysed and the same analysis was applied to Protestant frontier districts. One of the important factors making for high fertility proved to be the religious élan of the Catholics, which derived from their position as a strong minority. [ABSTRACT FROM AUTHOR]

This article focuses on the birth statistics of Massachusetts during the nineteenth century. The present paper is a report of an investigation which goes part of the way in surmounting the obstacles to our understanding of the trend of American fertility during the nineteenth century by trying to consider the very difficulty which one of these studies was forced to ignore. The difficulty referred to is the degree of under-registration of births in the statistics collected by States. Economist Joseph J. Spengler did try to take this question into account, but the method he used to answer, it failed to produce meaningful results. It should also be pointed out that whereas Spengler was concerned with all six New England States, this study is concerned only with the birth statistics of Massachusetts, which was the first State to inaugurate a registration system and whose birth records are generally considered to comprise the most reliable American statistics of the last century. The investigation covered the years between 1842, when the system was established, and 1901, making a 60-year period extending through the century.

This paper describes the test made by the United States Bureau of the Census to ascertain the completeness of birth registration in the United States. An outline of the method of procedure is given and some of the results of the test are mentioned. [ABSTRACT FROM AUTHOR]

In this paper the author estimates the compensating variation of income which will be necessary to keep the standard of living of a family constant when a child is born to the family. Various methods of estimation are tried, and an attempt is made to calculate the cost of a child in 1948, after allowances have been made for services provided by the government. [ABSTRACT FROM AUTHOR]

The article presents discussion on four aspects of sociologist B.O. Williams' paper. There may be some doubt as to whether people have reached the age of rationalism. There is, however, agreement that "informed and appraised procedures" should be delivered and supplied to society by the social scientists. Williams describes the method of investigation and said the analysis of probable, future effects must be cast in a theoretical frame of reference, that the venture is speculative and that the essential chain of arguments has been based on deductive reasoning in terms of the problematic approach. The one point where author called attention to is the omission of a consideration of the effects on the birth rate as one of the specific characteristics of the farm population. The only constructive suggestion put forth by Williams is the possible advisability of an admixture of industry, unless the mention of government relief as an alternative to a more desirable solution to be deemed.

The purpose of this article is to formulate some convenient summary measures for describing female lifetime fertility experience and, using these measures, to investigate certain macro-demographic consequences of changes in cohort childbearing patterns. Authors' aim is in part to report some substantive results relating to the effects of fertility changes and in part to illustrate what they think is a promising methodological approach. This article formulates some convenient summary measures of fertility patterns. These measures, which are based on the Gompertz function, are total lifetime fertility, median age of mothers at childbirth, and inter-quartile range of age of mothers at childbirth. Estimates of the parameters of Gompertz function, based on Canadian data, are used to derive, for each of the summary measures, values, which reflect historical fertility experience, and thus give an impression about the range of realistic values for these measures. A simple model of demographic activity, which includes the Gompertz function, is also considered, and this model is used in computer simulation experiments to determine the macro-demographic effects of changes in each of the three summary measures.

This article discusses the trends of childbearing in England and Wales. Unfortunately, the analysis of trends and patterns of fertility of marriage cohorts in England and Wales is marred by the lack of data on the parity-distribution of women at risk. In this paper a computerized model simulating the fertility of a hypothetical marriage cohort in a closed population is described. The model is designed as a non-stationary Markov process. It was programmed for an IBM 360 in FORTRAN IV and applied to England and Wales fertility data of marriage cohorts of the years 1951 to 1970. For each of these cohorts, the programme generated birth-order probabilities, constructed family size frequency distributions, and computed mean length of intervals between marriage and successive births, parity progression ratios and mean family sizes of fertile women. The tables were computed for all women married once only under 45 years of age combined, and for quinquennial age-at-marriage groups up to age 40.

Data are available to study the variation in mortality in this country occurring month by month for fully six decades. Death rates by month have been computed and published for the expanding death-registration area of the United States of 1900-1932 and for the complete nation (48 States and ultimately 50 States) from 1933 to the present. Even a cursory glance at the available data leads to the obvious conclusion that a definite pattern of seasonal variation of deaths exists. This seasonal swing is characterized by a high death rate in the early part of the year dropping to a trough in the summer months, and rising again during the latter part of the year. The general pattern is well recognized, as are similar seasonal curves for various causes of death. Despite the apparent wealth of statistical material at hand relatively little analytical matter has been produced in this country measuring seasonality of mortality as compared with the wide range of data compiled for statistical series portraying the nation's economic operations. Yet seasonal variation is receiving increasing attention in the evaluation of statistics of vital events. The very factors which make seasonal indices so valuable to economists and analysts also have proved to be of service to demographers and public health researchers. Seasonal adjustments provide refined information about current trends; they separate the seasonal components of statistical data from cyclical and irregular fluctuations; they provide indices with which to measure the significance of month to month change. Seasonal variation in the crude birth rate has been analyzed for the period 1933-40 using the link relative method [1]. Seasonal indices for 1948-54 were prepared with the aid of Univac, the high-speed electronic computer of the United States Bureau of the Census, using an adaptation of the standard ratio to moving average method [2]. The indices prepared by the Bureau of the Census became the basis for the regular computation of seasonally adjusted figures of births by the National Vital Statistics Division, U. S. Public Health Service 131. Similarly, marriage data published by the National Vital Statistics Division have been "deseasonalized" with the aid of methods developed by the Bureau of the Census [4]. This paper presents the results of an effort made with the assistance of Univac to eliminate seasonal variation from mortality data. Some of the particular problems encountered in adjusting mortality data, and the attempts to surmount these are described. [ABSTRACT FROM AUTHOR]

The ratio correlation method of estimating county population may be improved with the use of dummy variables and stratification to represent county "type." Unsatisfactory results were derived when the ratio correlation technique was applied to West Virginia counties using only such conventional symptomatic indicators as births, deaths, non-agricultural employment, and automobile registrations, probably due to the relatively unique absolute population decrease 1950-1960 that occurred in many counties. To improve the predictive power of the technique: counties were stratified along the lines recently suggested by Rosenberg; dummy variables were introduced to represent such county characteristics as region or rate of development; and stratification and dummy variables were combined in a single test. The average 1960 estimating error for the 55 counties was reduced from 4.6 to 2.3 percent when dummy variables and stratification were used to supplement the conventional indicators. [ABSTRACT FROM AUTHOR]

The article presents an analysis that deals directly with the level of fertility and, while not attempting an analysis of the long-term primary trend itself, does introduce one factor believed relevant thereto, namely, the desired consumption level of those in early childbearing ages. For the last few years, insight into the experience of a somewhat more homogeneous segment of the younger population--new high school graduates who did not go on to college--is provided by recent surveys of their employment status four months after graduation. Although the size of the group is small and sampling variability consequently greater, there is a striking rise in the employment and labor force figures for married females in this group, a finding at a more microscopic level consistent with the view just expressed. In recent years young persons' incomes have grown only hesitantly, and their unemployment rates have risen. The situation has been most severe among the lowest income segments of these groups.

The article presents a model for birth projections that contains birth probabilities for women, using age, cohort, and number of previous births as its essential parameters and including additional parameters that are psychological, economic, and sociological in origin. The article has three parts. First, the rationale is given for selecting these birth probabilities as the essential parameters. Second, the general procedure for estimating these parameters is given; this will involve the introduction of new parameters, both biological and social. Third, the general procedure will be illustrated in certain simplified special cases. In the course of the article, a number of relationships have very poor empirical estimates. From this perspective, one could argue that the article defines a program of research upon birth projections rather than a finished produce. From various cumulative distributions the author obtains cumulative births by multiplying the number of persons in each sample category by the number of children associated with that category save for the 7-and-up category that requires a special procedure.

This article focuses on trends in the fertility of married women of different social groups in certain rural areas of North Carolina. The trends in the fertility of living married women may be determined by means of a simple survey in which the following basic items of information are obtained for each married woman: first, age, or year of birth; second, age at time of marriage or year of marriage; and third, age at time each birth occurred or the year in which each birth occurred. Supplementary data regarding residence, color, occupation, tenure, education, relief status, etc., are, of course, necessary for analyzing the rates. Women who migrated from the areas studied have not been included in this study, while those migrating to the areas have been. The effect of this procedure is problematical. It is possible that the women who migrated to the cities had lower birth rates, in earlier years, than the women who remained in the country areas studied; and, hence, that a small downward bias would appear in the secular trend of the fertility rates of the women who remained in the areas.

The application of benefit-cost analysis to fertility, as suggested by Leibenstein and Becker, is another example of the power of micro-economic theory. However, it is important in the development of the theory of fertility to incorporate differences in economic environment, as reflected by the community of residence of the population. This proves to be the significant contribution of the demographers and sociologists to the theory of fertility differentials. The theoretical and econometric analysis of fertility presented in this paper casts doubt on much of the explanation of fertility differentials traditionally expounded by demographers. In our results, the most significant and consistent partial correlation between birth rates and level of living was a positive relationship for the farm population. This is in direct contrast to the inverse relationship between fertility and income that was believed to be well established by demographers. The difference in our results and the analyses by demographers is probably explained by the fact that the latter did not adequately account for the joint and partial effects of both community residence and level of living upon birth rates. The partial correlation between birth rates and the level of living index was weaker for the urban than the rural farm community but, nonetheless, positive. We feel that this may be, in part, a consequence of having to use a proxy for the urban level of living index since no index comparable to the one for rural farm was available. It is also likely that the heterogeneity of the urban area relative to the farm area will tend to weaken the results of a study at this level of aggregation. For the rural farm area a negative partial correlation was found for birth rates and the level of living index. This result is similar to the one found by demographers for the total population and may be explained by the same reasoning we have used to explain their total result, i.e., the simple correlation is a result of a blending of two different social groups with significantly different behavior patterns with respect to fertility. If these two groups were separable, we feel confident that the result predicted by theory would once more be forthcoming. A very important difference between our results and the analyses of fertility by demographers is the conclusion about race. Demographers explained the correlation between birth rates and race in this country as due to differences in population distribution by community residence for whites and nonwhites and the apparent fact that Negroes in a rural farm community were more fertile than whites in the same community. However, in our study, after accounting for both community residence and level of living, we found that race was not a statistically significant variable and, in fact, subtracts from the variance explained. Infant mortality rates proved to have a positive effect on birth rates confirming Weintraub's hypothesis that families react to bring their actual family size into line with their desired family size. The ratio of males to females in an area proved to be positively correlated with birth rates. This variable may be a proxy variable for the age composition of an economic area. The greater the proportion of people aged 15 or younger, the higher the sex ratio. Hence, the sex ratio may reflect a young population and pick up the higher fertility of younger women. Since age specific fertility data were not available by state economic area, it was not possible to standardize for this source of variation. [ABSTRACT FROM AUTHOR]