Contraceptive sterilization in Puerto Rico

For twenty years Puerto Rico has had the world’s highest prevalence of sterilization. From the 1982 Puerto Rico Fertility and Family Planning Assessment we examine whether the probability of obtaining sterilization is changing and what impact sterilization has on fertility, finding that the use of contraceptive sterilization has not declined and will probably continue to increase in Puerto Rico. Nonuse rather than temporary methods of contraception is the second most likely circumstance after sterilization. We also find that sterilization has reduced the total marital fertility rate by over 33 percent, thus having a significant effect on reducing the rate of natural increase; by all indications, it will have a greater effect in the future.     

The best-laid schemes: An analysis of discrepancies between migration intentions and behavior

A longitudinal survey approach is used in a largely rural area in the Philippines to examine consistency between migration intentions and subsequent migration behavior. Inconsistencies in movement behavior, the timing of a move, and the destination are analyzed. Discrepancies between intentions and behavior are explained in terms of unanticipated constraints and facilitators as well as changes in the conditions that precipitated the migration intention in the first place. Intended international movers who did not actually move in a 2-1/2 year period were thwarted mainly by legal hurdles that could not be overcome. Intended internal migrants who did not actually move remained in their origin area primarily because of changes in job opportunities or family relationships. Methodological and theoretical implications of the findings are discussed.The best laid schemes o' Mice an' Men Gang aft agley, An' la'e us nought but grief an' pain, For promis'd joy! we must bear in mind the distinction between direct and facilitating factors involved in migration processes . migration analysis should consider some factors that facilitate or impede migration rather than determine migration directly (Goldscheider, 1971:38).This article was originally presented at the annual meetings of the Population Association of American in Minneapolis, Minnesota, May 2–5, 1984. The authors wish to thank Lynna Sycip for her assistance in the preparation of the tabulations for this article. In addition to the authors, the co-investigators for this project are James T. Fawcett, East-West Population Institute and Ricardo G. Abad, Institute of Philippine Culture, Ateneo de Manila University. Research for this article has been supported by NIH Grant No. R01-HD13115, the Population Center Foundation, Manila, Philippines, and the East-West Population Institute.     

Will sex selection reduce fertility?

This paper investigates both theoretically and numerically the impact of sex selection on fertility. A static quantity-quality model of fertility is employed to compare fertility choices in two regimes: one in which parents cannot choose the gender of children and another in which parents can fully choose the gender of children. The static theory shows that whether sex selection reduces fertility depends on the second and third derivatives of the utility function and the child expenditure function. A numerical dynamic analysis is also presented. Using empirical dynamic models of fertility and Monte Carlo integration technique, the simulation shows that sex selection on the firstborn child among the Chinese in Malaysia could reduce fertility by about 3%.I thank the referees for their comments. I am indebted to James Heckman for providing generous computing support. Computational facilities were funded by NICHD Grant HD-19226 and NSF Grant SES-84-11242 to the Economics Research Center, NORC.     

Southern Negro Migration: Social And Economic Components Of An Ecological Model

This paper considers social and economic correlates of age-specific 1950-1960 net migration of Negro males from a sample of 150 southern counties. A model is developed with five components: (1) economic activity and urbanization, (2) white traditionalism, (3) demographic and ecological pressure, (4) nonwhite poverty, and (5) nonwhite home ownership. The dominant migration forces, as evidenced by correlations with component indicator variables, are the "pull" factor of change in nonprimary industrial employment, the "push" factor of population pressure in the nonwhite rural-farm sector, and the "push" of white traditionalism. However, the significance of model components varied when analyzed along age and industrial development continua. In the younger age groupings, industrial employment growth, population pressure, and white traditionalism were dominant migratory forces while in the older age groupings, industrial employment growth and non-home ownership were most significant. For Negro males in agricultural counties, the major migration propellents appeared to be the "push" of population pressure in the rural farm sector and non-ownership of homes. On the other hand the statistical explanation for Negro migration in more industrialized southern counties rests primarily with the "pull" of increased employment in non-primary industries along with population pressure. The importance of the findings for migration theory is discussed.     

Population dynamics and drought: A village in Niger

Summary The paper reports the results of demographic research in a rural village of about 1500 Hausaspeaking farmers in southern Niger, during the winter of 1973-74. The research site lies at the heart of the Sahel-sudanic zone just to the south of the Sahara, where drought, and in some areas, famine have exacted a heavy human, animal, and economic toll since 1968. The study was designed to measure and explain the change in the size and structure of the population during the years 1969-73. Social anthropological field techniques were used to ensure full and accurate reporting by community residents on all census topics. Data on rainfall and crop yields, on health and sanitary conditions, and on the political economy, social organization, and culture of the village were gathered in order to interpret the demographic situation The analysis of this data yields the following conclusions: 1. The population of the village appears younger (mean age: 15 years) and growing faster (mean doubling time: 23 years) than reported for Niger as a whole in 1972. 2. Contrary to what the researchers expected, the crude death rate, while relatively high to begin with, actually declined during the drought period (mean: 14.81); the crude birth rate remained very high (mean: 46.01), and the crude rate of increase rose from 1969 to 1973. 3. There was virtually no family out-migration from the target village during the drought, although the number of adult males participating in seasonal migrations to large West African towns rose from 35 per cent in 1969-70 to 75 per cent in 1973-74. 4. Problems of food production and distribution were acute, but thanks to the availability of donated foods, these were sufficiently short-lived during this drought cycle to make no discernible impact on population, although prolonged protein/calorie malnutrition among the very young may affect future fecundity.     

Some demographic consequences of changing cohort fertility patterns: An investigation using the Gompertz function

Abstract In this paper are formulated 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.     

A note on differential fertility in Sri Lanka

In this paper an attempt has been made to study differential fertility by urban-rural and regional classifications, using data obtained from complete tabulations of the 1963 Census of Population, the four rounds of the Socio-Economic Survey conducted from November 1969 to October 1970, and the Registrar General's Department. The analysis of current fertility indicates that the traditional pattern of lower urban fertility relative to rural held true in both 1963 and 1970 and also shows a narrowing of the differentials. The country was divided into four zones on an agro-climatic basis for regional analysis. A consistent ranking of the zones in relation to current fertility emerges in both 1963 and 1970. Changing patterns of age-specific fertility and age-specific marital fertility are discussed. Data on average size of family by urban-rural and regional classifications are also analyzed. An attempt has also been made to identify some of the possible causes for the differentials observed.     

Time series of growth in use of oral contraception and the differential diffusion of oral anovulents

Abstract Differential growth in the use of oral anovulents is explored through construction of separate time series for Canadian women classified by religion, education, and nativity. The series suggest that native-born Roman Catholic women are as likely as native-born Protestant women to be using oral contraceptives by the terminal point of our series in 1967. The period of very rapid growth in the use of orals appears to have come to an end. Differential patterns of diffusion of oral contraception shown by the categories of women discussed, suggest sources of bias in the profile of an aggregate time series.