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Cohort analyses in which the joint effects of aging, historical change and birth cohort membership are estimated for some dependent variable are often desirable on substantive grounds Unless two of these three variables are viewed as indexing identical unmeasured causal factors, any analysis which makes estimates for only two of the three variables is subject to spurious results. But three-way cohort analysis is problematic because age, time period and birth cohort are linearly dependent on each other. Although this con founding makes estimation of some three-way cohort models impossible, this paper demonstrates that estimation is feasible in a number of such models. By exploring estimates derived for some of these models from hypothetical data for which the underlying effects are known, this paper also shows that meaningful three-way cohort analysis is difficult unless the researcher entertains relatively strong hypotheses about the nature of aging, period and cohort effects. [ABSTRACT FROM AUTHOR]

The recent monograph on the status of women in Sociology, has empirically confirmed many of the suspicions about the predoctoral and postdoctoral careers of women in the discipline. However, while pointing an accusing finger or two, the study offers only a short-term perspective on institutional and interpersonal barriers to professional recognition. A perspective spanning a longer period of time and relating primarily to the research role is employed in this paper. Tracing two cohorts of American sociologists from academic origins to destinations allows to observe sex differences in research performance, visibility in the literature, and jobs subsequently attained. Present findings invite speculation about the denial of professional recognition to women. This study has delineated a more balanced approach implemented in a methodology that yields a more empirically differentiated picture of sociology than previously admitted.

This paper evaluates hypotheses which incorporate designated socioeconomic variables and male age specific incidences of labor force participation. Salient independent variables include education, net migration, unemployment, and earnings. The multiple regression method of analysis is utilized with 100 Standard Metropolitan Statistical Areas comprising the basic units of a cross-sectional analysis. Regression results generally substantiate hypotheses and concur with the findings of previous investigators. But, in contrast to earlier studies, education and net migration emerge as leading determinants of area! labor force patterns; and regression results for men in central age groups are impressive both in terms of the frequency of statistically significant relationships and size of co- efficients of determination. These departures from, the results of past research are possibly due to the implementation of a more meaningful and rigorous methodology. [ABSTRACT FROM AUTHOR]

The article cites a study which analyzes a cohort approach to the analysis of migration differentials. The problem to which this article addresses itself is whether or not a cohort approach to the analysis of historical series might yield further insight into association between economic fluctuations and rates of migration. By confining attention to a segment of the native population, in the present case to native white males, for whom intercensal rates of net interstate in-migration have been computed for each intercensal period from 1870 to 1950, the conditions necessary for following the experience of five-year cohorts from decade to decade are set up. The behavior of even cohorts has been examined. The rates of even cohorts reach their major peak at ages 20-24 if the cohorts attained these ages at the end of prosperous decades, but the major peak is at 30-34 if they became 20-24 at the end of a depressed decade and reached 30-34 at the end of the next decade which was in each case a prosperous decade. The rates of a cohort at ages 20-24 are invariably higher than those at 10-14. The pattern of rise and fall echoes the rise and fall of the index of economic activity.

The article focuses on the process of demographic translation. The conventional tables of demographic measurements are age-specific and time-specific. The customary mode of projection uses cohort or age components. Projections of age components tend to be blind to the implied distributional modifications for constituent cohorts. There is little logic to the relationship between the performance of one cohort in one period and the performance of the next cohort in the next period. On the contrary, translation projections can use assumptions about the time path of the cohort mean and variance. Any decent formula is not only an assistance in statistical analysis or practical projection, but also an expression of relationships from diverse frequency distributions. Regardless of the analytic priority of cohorts or periods in time series analysis, the translation formulae give both more meaning by indicating the implications for each of certain kinds of change in the other. The main task of the formal demographer is essentially the transformation of measurements from one shape into another to accommodate diverse analytic or policy purposes. In the present case, the translation formulae demonstrate clearly the relevance of distributional change as a focus for investigation.

Social change often takes the form of many small units, like persons or families, changing from "old-style" to "new-style" behavior, creating a behavioral trend. The rate of change is very important for the further effects. If middle-aged and old people are less likely to change, we get differences between birth cohorts at any given time and, for the population as a whole, delayed response to new conditions. Studies of rigidity and age generally support a fixation model of cohort behavior, and so do data on mobility and age. A tentative model of cohort effects is developed on this basis and the corresponding lag function shown; it implies a pattern of smooth oscillations in the behavioral time series with an average "period" of 25 years or more. The result has nothing to do with the distance between generations as customarily understood, i.e., from birth to marriage and child-bearing. [ABSTRACT FROM AUTHOR]

This paper replicates an earlier study of the determinants of the speed of admission to Pacific State Hospital. Data from both the 1960-61 and 1965-66 cohorts of applicants are compared. There was a dramatic change in the variables that differentiate admissions from nonadmissions. The degree of retardation becomes the primary consideration for admission in 1965-66 cohort in contrast to the family income which appeared to be most predictive of early admission in 1960-61 cohort. It is suggested that some implications of the structural and normative changes in both hospital and the community are related to these findings. [ABSTRACT FROM AUTHOR]

This article follows on the report to previous research concerned with the effectiveness of pacifist tactics in modifying an adversary's behavior in a bargaining game, in which details of game procedures are presented. The present studies focus on the potential effects of two "outsider" or third- party influences on the pacifist-adversary relationship: first, of adversary-cohorts (teammates) who provide encouragement in opposition to the pacifist, and second, by contrast, of an onlooker whose presence exposes the bargaining process to a party not directly involved in the outcomes. To establish the proper context for the follow-on nature of the present paper, the previous findings are reviewed. The rationale for bringing pacifism into the laboratory is, of course, control. Outside the laboratory, pacifists rarely function in isolation from others seeking the same ends; and the contamination is most marked when, more often than not, the pacifist shares a common cause with violent militants. In these circumstances, it is virtually impossible to determine the effectiveness of pacifism per se.

This paper expands the conceptual apparatus of family life cycle analysis and illustrates its usefulness by applying it to a population. There is a normatively sanctioned life cycle that a female born into American society is expected to follow as she moves from birth to death: she is expected to survive through childhood, marry, bear and rear children, and survive jointly with her husband until her Children leave the home. Paul Glick, in several articles, has calculated mean ages at which these Various events are experienced. The life cycle analysis proposed here, however, focuses on the distribution of women according to type of life cycle experienced. Starting with a cohort of 100,000 females, six alternative life cycle possibilities are differentiated and the number who follow each of the types is calculated. Types are: (1) abbreviated, the female dies before she is exposed to the risk of marriage; (2) spinster, the woman is exposed to the risk of marriage but does not marry; (3) barren, the woman marries but remains childless; (4) dying mother, the women has children but dies before the last one leaves home; (5) widowed mother, the women has children and survives until they leave home, but her husband dies before that event; and (6) typical, the woman marries, has children, and survives jointly with her husband until the last one leaves home. Applying this approach to several cohorts of native-born Massachusetts women born at different times some striking changes appear. For examples the number of women from a birth cohort of 1000,000 who follow the typical life cycle increases from 21,000 for the cohort born in 1830 to 57,000 for the cohort born in 1920. The demographic, social and economic implications of a change of this magnitude are of considerable consequence. [ABSTRACT FROM AUTHOR]

Data representing `social strategies of family formation' of the female birth cohorts with completed fertility and enumerated in the censuses of England and Wales, 1911 and 1951, and in the 1946 Family Census are presented here. These data include simple estimates of numbers and percentages controlling or attempting to control fertility as well as estimated parity distributions of those controlling fertility in the various separately identified cohorts and sub-cohorts; and all the estimates are given by age at marriage. The most spectacular change over time is the consistent increase in estimated percentage controlling or attempting to control fertility in the successive cohorts represented. Among women in the cohort born 1831-45 less than 20% controlled or attempted to control fertility; but more than 72% of the women in the cohort born 1902-06 controlled or attempted to control fertility according to these estimates. There is some increase over time in the percentage marrying at ages under 20 years, and there is also some support for the hypothesis that the increase in early marriage is associated with the spread of fertility control. The percentage childless among those controlling or attempting to control fertility appears to decrease overall, although in some social status groups it increases over time. On the other band, actual fertility as measured by the proportion with exactly three or with three or more live births decreases over time in all the social status categories. [ABSTRACT FROM AUTHOR]

This study is based on a data record developed for 7,609 mortgage originations by one of Pittsburgh's leading mortgage lenders through the resources of the Federal Savings and Loan Insurance Corporation. Cohort analysis is used to construct continuous delinquency rates for mortgages made from 1961 through 1972 on single-family homes located within the Pittsburgh SMSA. This grouping technique combines mortgages with like combinations of characteristics and allows annual delinquency rates to be calculated on the mortgages in each cell. These rates are then regressed on the variables used in the construction of each cohort. Because any collinearity that may exist between the explanatory variables in the ungrouped data is eliminated through the construction of cohorts for all possible combinations of variables, if at least some of the unusual combinations can, in fact, be found in the sample, this technique is designed to yield coefficients whose statistical significance can be tested precisely. [ABSTRACT FROM AUTHOR]

The purpose of this study is to develop an alternative method to the traditional cohort survival technique for long-run forecasting of public school enrollment by small area. In the model presented, the difference between first grade enrollment and resident births lagged six years is viewed as a function of new housing, busing, and the percent of lagged births that are white. Least squares regression analysis was used to test the model on data in four neighborhoods in New York City for the period 1958-1969. While the model fits the historical data rather well, its usefulness for long-run forecasting is diminished in areas experiencing substantial structural change. [ABSTRACT FROM AUTHOR]

A probability model to estimate fecundability of a married woman has been proposed under some mild assumptions. It utilises the knowledge on the susceptibility status of the married women (including menstruation, menopause, pregnancy and amenorrhea) and therefore sets another approach for estimating fecundability. In addition, it is capable of predicting the parity, proportion of foetal losses, fecundability and incidence of secondary sterility. The problem of finding out the consistent estimates of the parameters in the distribution is discussed in section 4. For illustration, the model is applied to a set of simulated data after simplifying many assumptions of the model. [ABSTRACT FROM AUTHOR]

Cross-sectional data on voter turnout and political interest from 28 American national surveys, and data from a cohort analysis of voter turnout, indicate a Pronounced increase in political interest and participation from young adulthood to middle age. Voter turnout apparently remains almost constant from middle age to advanced maturity, and average political interest apparently increases. These findings are related both to theories of political participation and to Cumming's and Henry's notion of disengagement of the aged. Some pitfalls of the use of cross-sectional data to infer changes with aging are discussed. [ABSTRACT FROM AUTHOR]

Society persists despite the mortality of its individual members, through Processes of demographic metabolism and particularly the annual infusion of birth cohorts. These may pose a threat to stability but they also provide the opportunity for societal transformation. Each birth cohort acquires coherence and continuity from the distinctive development of its constituents and from its own persistent macroanalyic feaures. Successive cohorts are differentiated by the changing content of formal education, by peer-group socialization, and by idiosyncratic historical experience. Young adults are prominent in war, revolution, immigration, urbanization and technological change. Since cohorts are used to achieve structural transformation and since they manifest its consequences in characteristic ways, it is proposed that research be designed to capitalize on the congruence of social change and cohort identification. [ABSTRACT FROM AUTHOR]

The research reported here involves an age cohort analysis of inter-generational mobility in a nation-wide sample of adult males. The data were obtained by the Survey Research Center of the University of Michigan in its study of the 1932 presidential election. For purposes of the present analysis, respondents and their fathers were divided into three occupational categories: white collar workers, blue collar workers and farmers. For purposes of the present analysis the fifth decade of life was selected as the basis for comparisons because it seemed that this decade in the careers of the respondents most often and most closely matched the period in their fathers' careers to which respondents referred when asked what their fathers' occupations had been when they were growing up. Furthermore, by the fifth decade occupational stability has been achieved in the lives of most men; thereafter there is relatively less intra-generational mobility. In order to standardize comparisons among cohorts for the fifth decade, it was necessary to devise one procedure for reconstructing the occupational distribution in the two oldest cohorts.

The article presents cohort analysis of fertility rate among native white woman in the United States. It is generally agreed that the much higher fertility of 1947-49 than of 1933 is due primarily to conditions associated with the great depression of the early 1930's and with postwar demobilization and prosperity. Opinions differ widely, as to the extent to which the 1947-49 boom in babies represents: a reversal of the long-time downward trend in average family size, and an unusual concentration in a few years of the births occurring with the continuance of the downward trend. The cohort material to be presented here in an attempt to evaluate the importance of these two explanations relates to native white women. The article suggests that the number of births during 1950 and later years will be reduced by the large borrowing on the future which has occurred prior to 1950. The reduction will be gradual and will extend over a long period if prosperity continues, for this will encourage the continuation of early marriage and the early bearing of the children wanted. But if economic conditions deteriorate substantially, the drop in births which a depression alone would bring will be augmented greatly by the moving ahead of several hundred thousand births from 1950 or later to 1947-49.

Residence histories, collected retrospectively from a national sample in 1958, permit identification of six successive age cohorts among the population reporting a farm birthplace. The members of each cohort are classified by place of residence at ages 18, 24, 34, and 44, which are viewed as distinctive points in tile life cycle. Two principal topics are considered: rates of retention on farms at successive life-cycle stages (or, in complementary terms, age at leaving farms), and types of nonfarm residence. Among each cohort, off-farm movement is substantial by age 18, and continues during each subsequent age period. The younger the cohort, the greater this movement at earlier stages in the life cycle. Among those moving off-farm, a distinctive distribution by type of place, established early in the life cycle of each cohort, persists throughout the life cycle. The majority of persons of nonmetropolitan-farm origin continues to live in nonmetropolitan areas, whereas nearly all persons of metropolitan-farm origin reside throughout life in metropolitan areas. [ABSTRACT FROM AUTHOR]

One approach to the study of social and organizational change is the study of life histories of strategic cohorts. This approach is particularly appropriate for military elites because of the marked age grading in education, selection, and career development. Thus, the officer who is slow in his movement through the ranks is clearly recognized as "over-age in grade." Cohort analysis must be seen in the light of external events affecting the cohort. The demands placed upon the American military establishment during this century have altered the nature of relations between the civilian and military sectors of society. American involvement in two world wars and in postwar world politics has required a vast expansion of the armed forces which was achieved through widespread enlistment and conscription of "civilian soldiers." The increasingly complex technology of warfare and of military organization, moreover, required professional skills other than those traditionally taught within the service academies. Thus, there has been a tendency toward "reciprocal interpenetration" of the civilian and military spheres. The defining characteristics of this interpenetration are (1) a convergence of the skills required in the civilian and military spheres as the technological bases of both systems become more complex; (2) a broadening of the base of military recruitment generally and of officer recruitment specifically, so that nonacademy graduates are admitted to the officer corps; (3) the presence of civilian personnel employed within the military system. [ABSTRACT FROM AUTHOR]

Population analysis is important to city planning because design standards are usually expressed in terms of population. Almost everything the planner does is measured in relation to population, its size, distribution and composition. Without the estimates called for by design standards, the planner would be unable to set the scale for the long-range plan. City planners traditionally grounded in architecture and engineering, are becoming more research-minded. The 1950 National Planning Conference, for example, gave considerable time to problems of planning research. The recent techniques being evolved for city planning show considerably more sophistication than those in use twenty years ago. A favorite method during the 1920's was that of superimposing the curve for a given city on curves for older, larger cities as a guide or extrapolation. An alternate method in favor at the time was that of the fitted exponential curve. Both usually overshot their mark, and gave way successively to the logistic curve, the ratio method and cohort-survival analysis. This continuing improvement is definitely desirable.

In this article cohort analysis is used to study the impact of generations on changes in political behavior and to distinguish the effects of generations from those due to aging. Four variables from Survey Research Center polls conducted between 1952 and 1968 are examined. A generation effect is found to influence opinions on aid to education, but isolationism shows a generation effect and life-cycle (aging) effect predominating at different times. The expected importance of the life cycle for voter turnout is supported, but neither effect is found to influence party identification substantially. [ABSTRACT FROM AUTHOR]

Demographers have attempted to graduate schedules of age-specific fertility rates since the 1930's and there are now several functions which could be fitted to these rates. But little work has been done to date to construct model schedules of fertility. An exploratory study to examine the possibility of fitting certain mathematical formulae to cumulative fertility rates of marriage cohorts in England and Wales revealed the existence of a common pattern showing how mean family sizes of the different age-at-marriage groups of a given marriage cohort, are built up over the childbearing span. To test the adequacy of the generated system for describing observed fertility distributions, the researchers have estimated the distribution of mean family sizes by age at and duration of marriage, for a selection of marriage cohorts of completed fertility in England and Wales and Sweden using various methods. The adequacy of the generated system to describe widely different childbearing patterns suggests that the researchers have a useful tool for fertility projections because, if they are prepared to accept the idea that "a marriage cohort carries its own fertility pattern with it", it follows that changes in fertility patterns consist mainly of a shift of the location of the cumulative fertility curve on the standardized vertical and horizontal scales.