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Biomedical subjects

John Bongaarts

Publications and source records attributed to John Bongaarts.

5 recordsLinked to original sources

Long-range trends in adult mortality: models and projection methods.

In the study reported here, I had two objectives: (1) to test a new version of the logistic model for the pattern of change over time in age-specific adult mortality rates and (2) to develop a new method for projecting future trends in adult mortality. A test of the goodness of fit of the logistic model for the force of mortality indicated that its slope parameter is nearly constant over time. This finding suggests a variant of the model that is called the shifting logistic model. A new projection method, based on the shifting mortality model, is proposed and compared with the widely used Lee-Carter procedure.

Adult↗

Estimating mean lifetime.

The life expectancy implied by current age-specific mortality rates is calculated with life table methods that are among the oldest and most fundamental tools of demography. We demonstrate that these conventional estimates of period life expectancy are affected by an undesirable "tempo effect." The tempo effect is positive when the mean age at death is rising and negative when the mean is declining. Estimates of the effect for females in three countries with high and rising life expectancy range from 1.6 yr in the U.S. and Sweden to 2.4 yr in France for the period 1980-1995.

Age Factors↗

Completing the fertility transition in the developing world: The role of educational differences and fertility preferences.

This study summarizes patterns of educational differentials in wanted and unwanted fertility at different stages of the fertility transition. The data are from Demographic and Health Surveys in 57 less developed countries. As the transition proceeds, educational differentials in wanted fertility tend to decline and differentials in unwanted fertility tend to rise. An assessment of fertility patterns in developed and less developed countries with low fertility concludes that these differentials are likely to remain substantial when less developed countries reach the end of their transitions. This conclusion implies that the educational composition of the population remains a key predictor of overall fertility in late transitional countries and that low levels of schooling can be a cause of stalling fertility.

Birth Rate↗

Living arrangements of older adults in the developing world: an analysis of demographic and health survey household surveys.

OBJECTIVES: This study examines living arrangements of older adults across 43 developing countries and compares patterns by gender, world regions, and macro-level indicators of socioeconomic development. METHODS: Data are from Demographic and Health Surveys. The country is the unit of analysis. Indicators include household size, headship, relationship to head, and coresidence with spouse, children, and others. Unweighted regional averages and ordinary least-squares regressions determine whether variations exist. RESULTS: Average household sizes are large, but a substantially greater proportion of older adults live alone than do individuals in other age groups. Females are more likely than males to live alone and are less likely to live with a spouse or head of a household. Heading a household and living in a large household and with young children is more prevalent in Africa than elsewhere. Coresidence with adult children is most common in Asia and least in Africa. Coresidence is more frequent with sons than with daughters in both Asia and Africa, but not in Latin America. As a country's level of schooling rises, most living arrangement indicators change with families becoming more nuclear. Urbanization and gross national product have no significant effects. DISCUSSION: Although living arrangements differ across world regions and genders, within-region variations exist and are explained in part by associations between countrywide levels of education and household structure. These associations may be caused by a variety of intermediating factors, such as migration of children and preferences for privacy.

Adolescent↗

Future trends in contraceptive prevalence and method mix in the developing world.

This study reviews existing methodologies for projecting future trends in contraception, evaluates the validity of the assumptions underlying these projections, proposes methodological improvements, and assesses the prospects for new methods of contraception in the coming decade. Demand for contraception can be expected to continue to rise rapidly for the next few decades as populations continue to grow and fertility declines to approach replacement level. As a result of these trends, the number of contraceptive users in the developing world is expected to rise from 549 to 816 million during the next 25 years, according to the most recent UN projection. An examination of the projection methodology found it to be reasonable. Projecting the future distribution of specific contraceptive methods is more difficult. Method choice is affected by trends in several factors, including access to different methods, user characteristics, and technology. The procedure employed by the Futures Group to project method mix was found to be less than optimally designed, and a new methodology is, therefore, proposed.

Contraception↗