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PubMed1982

A reassessment of world population trends.

This reassessment is limited to observations concerning trends in mortality and fertility and concerning longrun prospects for population growth. Recorded changes in mortality are compared with 3 projections made many years ago. Projections of European mortality made in 1941-42 understated by a wide margin the actual increase in expectation of life because of unforeseen technological changes in the prevention and cure of fatal disease. On the other hand, a projection made in 1955 for India, foreseeing a rapid rise in the 1950s and slower progress later on because of the exhaustion of the easier gains, appears to have been accurate and also to depict the prospects in other populations of relatively high mortality and low income. A different projection of life expectancy in Mexico was also quite close to actual changes in Mexican mortality; it was based on a universal curve constructed to represent how life expectancy rises, increasing ever more slowly as it approaches an upper limit. This curve (1 for each sex), constructed for projection of Mexican mortality, is employed as a standard of comparison for mortality changes in many countries. A number have followed the standard for females very closely for more than 3 decades; in developed countries, male life expectancy has generally fallen short of the standard. The almost universal low fertility in developed countries contrasts with the great diversity of levels and trends of fertility in developing countries, some of which retain undiminished high fertility and others of which have recently attained rates of childbearing as low as in the developed areas. Instances of surprisingly little change and surprisingly rapid change in fertility are described. In the future, growth of populations of developed countries will probably be slight; the future rate of increase in the developing areas depends on the unpredictable timing and pace of childbearing reduction in populations where fertility remains high. In the long run, world population growth may resume its typical pattern of moderate growth interrupted by catastrophic setbacks.

Australia↗
PubMed1982

Long-range global population projections, as assessed in 1980.

UN medium range projections prepared in the 1980 assessment projected the population of individual countries up to the year 2025. The long range projections discussed here were prepared by projecting the population of 8 major world regions from 2025-2100. The purpose of the projection was to observe the implications of the changes from the 1978 assessment made in the 1980 medium range projections on the long range projections of the world's populations. As in previous projections, high, medium, and low variants were prepared in which fertility is assumed to be constant at the replacement level but at different times in the future. In addition, these projections contain 2 variants not previously prepared--namely, the growth and decline variants, in which the ultimate net reproduction rate is 1.05 and 0.95, respectively. In all the variants, expectation of life at birth is assumed to reach 75 years for males and 80 for females. According to the current medium variant projection, the earth's population will become stationary after 2095 at 10.2 billion persons, compared with a total of 10.5 billion projected in the 1978 assessment. The lower projection is largely attributable to a recent decline in the growth rate of several countries in South Asia which was greater than previously assumed. When the world population becomes stationary, both crude birth and death rates would be about 13/1000. In the decline variant, total population would peak at 7.7 billion in 2055, then decline gradually to 7.2 billion in 2100. The total population as projected by the growth variant would equal 14.9 billion in 2100 and would still be growing slowly. Between 1980 and 2050, 95% of the world's growth will occur in the currently less developed regions. Their share of total population will increase from 75-85% during that period. The age structure in all regions is expected to converge to 1 in which the median age is 39 years, the proportion both below age 15 and above age 64 is about 19% each, and the dependency ratio is about 60. A precise degree of accuracy cannot be specified, but the argument is made that the actual future population of the world is very likely to fall within the range of the projection variants and probably not far from the medium variant.

Africa↗
PubMed1982

Infant mortality: world estimates and projections, 1950-2025.

Although the infant mortality rate is considered 1 of the preferred indicators for describing both demographic conditions and the overall and social economic well-being of a country, comparable and consistent estimates and projections of infant mortality for all countries of the world have been lacking. In an attempt to improve this situation, the UN Population Division, with the support and encouragement of the UN Children's Fund and the assistance of the World Health Organization and the UN regional commissions, has recently completed a comprehensive project which provides estimates and projections of infant mortality for all world countries for the period 1950-2025. This article reviews the estimates and projections produced by this project. The various sources and the quality of the data, as well as the methods employed to estimate current and past levels of infant mortality and to project future trends, are reviewed and evaluated. The article concludes with a discussion of the results vis-a-vis the goals set for infant mortality by the World Population Plan of Action and the International Development Strategy for the 3rd UN Development Decade.

Data Collection↗
PubMed1982

Net migration by commercial air: a lower bound on total net migration to the United States.

"This article presents evidence that net migration to the United States by commercial air alone was between 400 and 500 thousand a year over the period 1969 to 1978. This evidence is drawn from data gathered by the U.S. Department of Transportation in cooperation with the Immigration and Naturalization Service, by the International Air Transport Association, and individually by 20 major international airports in the United States. Net migration by commercial air may be used as a lower bound to total net migration to the United States. The latter would include, in addition to net migration by commercial air, net migration by land, by sea, and by clandestine and noncommercial (military- and government-chartered) air." The author concludes that "total net migration to the United States exceeds by a significant margin estimates of total net migration published by the U.S. Bureau of the Census, which have averaged around 370 thousand over this same period, as well as recent estimates published in the demographic literature of between 500 and 600 thousand per year." A critique by Jennifer Marks (pp. 351-5) and a reply by Vining (pp. 357-60) are also included.

Americas↗
PubMed1982

The new Kuznets cycle: a test of the Easterlin-Wachter-Wachter hypothesis.

The aim of this paper is to evaluate the Easterlin-Wachter-Wachter model of the effect of the size of one generation on the size of the succeeding generation. An attempt is made "to identify and test empirically each component of the Easterlin-Wachter-Wachter model..., to show how the components collapse to give a closed demographic model of generation size, and to investigate the impacts of relative cohort size on the economic performance of a cohort." The models derived are then used to generate forecasts of the U.S. birth rate to the year 2050. The results provide support for the major components of the original model.

Americas↗
PubMed1979

Demographic characteristics of the rural population of Ethiopia.

"In the field of population studies, Ethiopia has neither carried out even a single population census nor established a vital statistics registration system. But with the available scanty and defective data, attempts are made here to examine the demographic situation of rural Ethiopia. Since only about 13% of the total population of the country are estimated to reside in agglomerations of 2,000 and above, Ethiopia is predominantly rural. According to the estimates of the vital rates, Ethiopia has been experiencing high levels of fertility and mortality conditions. "The low average life expectancy at birth, together with the high birth and death rates can indicate the low level of living which has been prevalent in the country."

Africa↗