World Population Projections Research Articles

Evaluating effective measles vaccine coverage in the Malaysian population accounting for between-dose correlation and vaccine efficacy

BackgroundMalaysia introduced the two dose measles-mumps-rubella (MMR) vaccine in 2004 as part of its measles elimination strategy. However, despite high historical coverage of MCV1 and MCV2, Malaysia continues to report high measles incidence. This study suggests a novel indicator for investigating population immunity against measles in the Malaysian population.MethodsWe define effective vaccine coverage (EVC) of measles as the proportion of a population vaccinated with measles-containing vaccine (MCV) and effectively protected against measles infection. A quantitative evaluation of EVC throughout the life course of Malaysian birth cohorts was conducted accounting for both vaccine efficacy (VE) and between-dose correlation (BdC). Measles vaccination coverage was sourced from WHO-UNICEF estimates of Malaysia’s routine immunisation coverage and supplementary immunisation activities (SIAs). United Nations World population estimates and projections (UNWPP) provided birth cohort sizes stratified by age and year. A step wise joint Bernoulli distribution was used to proportionate the Malaysian population born between 1982, the first year of Malaysia’s measles vaccination programme, and 2021, into individuals who received zero dose, one dose and multiple doses of MCV. VE estimates by age and doses received are then adopted to derive EVC. A sensitivity analysis was conducted using 1000 random combinations of BdC and VE parameters.ResultsThis study suggests that no birth cohort in the Malaysian population has achieved > 95% population immunity (EVC) conferred through measles vaccination since the measles immunisation programme began in Malaysia.ConclusionThe persistence of measles in Malaysia is due to pockets of insufficient vaccination coverage against measles in the population. Monitoring BdC through immunisation surveillance systems may allow for the identification of susceptible subpopulations (primarily zero-dose MCV individuals) and increase the coverage of individuals who are vaccinated with multiple doses of MCV. This study provides a tool for assessment of national-level population immunity of measles conferred through vaccination and does not consider subnational heterogeneity or vaccine waning. This tool can be readily applied to other regions and vaccine-preventable diseases.

World population projections: Just little bits of history repeating?

Abstract The world population is expected to peak in the summer of 2086. But do the official United Nations estimates give enough consideration to human behaviour? Danny Dorling gives his verdict

Selected Results of the 2019 UN World Population Projections

Population and Development ReviewVolume 45, Issue 3 p. 689-694 DOCUMENTSToken Access Selected Results of the 2019 UN World Population Projections First published: 06 September 2019 https://doi.org/10.1111/padr.12288Citations: 5Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume45, Issue3September 2019Pages 689-694 RelatedInformation

Invariant Causal Prediction for Nonlinear Models

AbstractAn important problem in many domains is to predict how a system will respond to interventions. This task is inherently linked to estimating the system’s underlying causal structure. To this end, Invariant Causal Prediction (ICP) [1] has been proposed which learns a causal model exploiting the invariance of causal relations using data from different environments. When considering linear models, the implementation of ICP is relatively straightforward. However, the nonlinear case is more challenging due to the difficulty of performing nonparametric tests for conditional independence.In this work, we present and evaluate an array of methods for nonlinear and nonparametric versions of ICP for learning the causal parents of given target variables. We find that an approach which first fits a nonlinear model with data pooled over all environments and then tests for differences between the residual distributions across environments is quite robust across a large variety of simulation settings. We call this procedure “invariant residual distribution test”. In general, we observe that the performance of all approaches is critically dependent on the true (unknown) causal structure and it becomes challenging to achieve high power if the parental set includes more than two variables.As a real-world example, we consider fertility rate modeling which is central to world population projections. We explore predicting the effect of hypothetical interventions using the accepted models from nonlinear ICP. The results reaffirm the previously observed central causal role of child mortality rates.

Extrapolation of population grids for risk analysis

To fulfill its mission of control within the framework of the FSOA (French Space Operation Act), including in particular the monitoring of safety requirements for people and property, CNES has developed and has been using since eight years the model and tool ELECTRA, especially designed to estimate human risk during launch and controlled or uncontrolled re-entry. The major contributor in probabilistic assessment of human risk is the population density on areas where some re-entry fragments may fall. In this framework, information about population spatial distribution at a global scale is a key parameter. In particular, CNES needs to have an estimation of the evolution of population for future decades to estimate risk during launch phase and re-entry for future space missions presently in preparation.The objectives of the CNES POPSCAN study, started in 2011 with SERTIT, include census of available databases about worldwide population, qualitative and quantitative analyses of these data and proposals to improve population models used in risk analysis.In this paper, we present a method to extrapolate until 2050, at different time steps, the world population grid provided by CIESIN (Columbia University), i.e. the GPW-V4-UN-adjusted geo-referenced raster dataset. Reasons having led to the choice of this particular database are presented as well as some of the main existing extrapolation methods. The method exploits existing geo-spatial population information at a grid cell level provided by past population distribution grids and computes the successive future population layers: it is based on an exponential approach with an adjustment to UN projections (United Nations World Population Prospects, the 2015 Revision). This approach combines two advantages: keeping the gridded representation of population distribution from geo-data bases such as GPW and benefiting from the tabular data computed by UN and their sophisticated methods for world population projections.

The 2015 Revision of the UN's World Population Projections

The 2015 Revision of the UN's World Population Projections

NEW UNITED NATIONS WORLD POPULATION PROJECTIONS

New United Nations World population projections have just been released. This article describes and comments on the main features of these projections, including those for Australia. Comparisons with previous sets of projections are made, and the issue of projection uncertainty is briefly addressed.

Global estimates and projections of world populations

The United Nations 2002 Revision of the world population projections has radically reviewed the results of the preceding revision. The results obtained show that it is reasonalbe revision. The results obtained show that it is reasonable to dispel the fear of an excessive and perhaps uncontrolled growth of world population, which alarmed public opinion and many international organizations in the last decades. Even in the medium variant, by the year 2050 world population will be less than 9 billion, with zero growth. In view of the fact that fertility will remain below replacement level, after that a process of slow decrease might set in, despite a further sharp increase in survival rates.

Provision of Care

Provision of Care

The future of fusion

The population of the world is increasing, mainly in the developing world, and is projected to saturate within about 100 years at up to twice the present population of 6 billion people (Bos et al., World Population Projections: 1994–95 Edition, Published for the World Bank). Studies (Goldemberg and Johansson (Eds.), Energy as an Instrument for Socio-Economic Development United Nations Development Programme, New York, 1995, p. 9; United Nations Statistical Yearbooks, 10th issue; 1965; 20th issue; 1975, 22nd issue, 1977; 32nd issue, 1987; and 39th issue 1994, United Nations Publications; Sheffield, J. Technol. Forecasting Social Change 59 (1998) 55.) show that, historically, the population growth rate has varied inversely as the annual per capita energy use in most parts of the developing world, where per capita energy use is typically less than 1 t of oil equivalent energy per year. However, in areas with more than 2–3 t of oil equivalent of energy use per year per person, the growth rate is around zero. If this trend continues, a stable world population will require, allowing for energy efficiency improvements, some 2–3 times the present annual energy use. There is an abundance of energy in the world both exploited and potential to meet this need – fossil, fission, and renewables – but it is not evenly distributed, some are costly, and there are issues of environmental pollution in present use, that may limit use. Fusion energy is a potential longer-term source with attractive environmental features. It is the least-developed energy option and still faces a challenging development path, but there are many areas of the world that would benefit hugely from its deployment from the later part of the 21st century onward, and it is important to consider how it might be deployed. Most fusion power plant options considered today show an economy of scale, owing to the fixed distance needed for shielding fusion neutrons, tritium breeding and handling the heat loads. One interesting approach is to use the power plant to co-produce electricity and hydrogen to facilitate the introduction of lower cost of electricity, multi-gigawatt power plants (Sheffield et al., A study of options for the deployment of large fusion power plants, 2000, to be published).

Nations Unies. World Population Prospects. The 1996 Revision. New York, Department of Economie and Social Affairs, Population Division, ST/ESA/SER.A/167, 1998, 839 pages. Nations Unies. World Population Projections to 2150. New York, Department of Economie and Social Affairs, Population Division, ST/ESA/SER.A/173, 1998, 41 pages.

Nations Unies. World Population Prospects. The 1996 Revision. New York, Department of Economie and Social Affairs, Population Division, ST/ESA/SER.A/167, 1998, 839 pages. / Nations Unies. World Population Projections to 2150. New York, Department of Economie and Social Affairs, Population Division, ST/ESA/SER.A/173, 1998, 41 pages.. An article from journal Cahiers québécois de démographie (L’union libre), on Érudit.

World Population Projections for Greenhouse Gas Emissions Scenarios

A survey is made of the latest world population projections issued by the United Nations, World Bank, U.S. Census Bureau, and International Institute for Applied Systems Analysis. Medium variants from all the organizations show excellent agreement with respect to many features of future world population growth. It appears that little would be gained by obtaining additional regional projections made by governments or organizations other than those listed above. In general, the new range of population projections that are candidates for forthcoming IPCC emissions scenarios are narrower and lower than the previous IPCC IS92 population range: a reflection of updated information on the decline of fertility rates in developing countries and the incorporation of a plausible correlation between mortality rates and fertility rates within the IIASA ‘rapid’ and ‘slow’ demographic transition variants. Comments are made on the schematic approach of forecasting CO2 emissions using multiplicative identities such as ‘IPAT’ (impact/emissions = population × affluence × technology). Although the unqualified IPAT model suggests that emissions should scale linearly with population, a number of caveats to this exist, the most important of which may be factor interactions. A brief review is made of conventional thinking about interactions between population growth and economic development. Correlation studies and theory suggest that population growth has a neutral or, at most, weak negative effect on economic growth. Conversely, it is well established that higher per capita incomes are well correlated with lower fertility and mortality rates in developing countries. Therefore, a plausible first-order relationship worth exploring in the next generation of IPCC scenarios is that scenarios with higher average economic growth rates in the developing world should be associated with lower fertility and mortality rates there. Calculations are presented that illustrate the effect this negative correlation could have had on the range of the older IS92 emission scenarios, assuming that all other factors are unchanged. Finally, some policy issues concerning population and global warming are reviewed in connection with the IPCC’s omission of population policy discussion in its 1995 Second Assessment Report.

How Accurate Are the United Nations World Population Projections?

This paper investigates the accuracy of the UN world population forecasts of the age structure and crude birth and death rates in seven major regions of the world. Focus is on comparative accuracy across regions and over time utilizing data from 12 UN forecasts for Africa Asia Europe the former Soviet Union Latin America northern America and Oceania prepared between 1950 and 1985. Overall it is noted that the strength of these projections is that they contain detailed results for each country of the world computed on the basis of one consistent methodology and that they are updated frequently in the light of the most available data and methods. Compared with ex-post observed real trends the 12 sets of projections show a clear tendency over time toward greater accuracy. Part of the accuracy improvement is attributable to better data for base populations. In addition there is considerable regional heterogeneity in the accuracy of the UN projections. It is recommended however that the UN should include more than one variant for mortality in the projections due to difficulties with extrapolation and the considerable impact of exempting a variant on the results.

World population projections for the 21st century: theoretical interpretations and quantitative simulations

World population projections for the 21st century: theoretical interpretations and quantitative simulations

World population projections: estimates and projections with related demographic statistics

World population projections: estimates and projections with related demographic statistics

Long-range World Population Projections: Two Centuries of Population Growth, 1950-2150.

Long-range World Population Projections: Two Centuries of Population Growth, 1950-2150.

World Population Projections 1984: Short- and Long-Term Estimates by Age and Sex with Related Demographic Statistics.

This edition of World Population Projections contains an up-to-date assessment of demographic prospects through the year 2150. From data available as of early 1994, demographic profiles were drawn for 206 countries, economies and territories, including separate projections for the countries of the former Soviet Union. These detailed projections show total population by age and sex, birth and death rates, migration levels, population growth, fertility and reproduction rates, infant mortality, and life expectancy. In addition to the country profiles, World Population Projections contains projections for the world as a whole, for industrial and developing countries, and for particular regions and income groups. The introduction to the detailed tables highlights trends in demographic indicators in different regions of the world and describes the methodology used in making the projections, including new procedures used to incorporate AIDS mortality in the projections. A list of the data sources is also included in the introduction. New to this edition is a section on alternative projections.

People, skills, and resources: An interaction model for world population growth

A model is set up that yields the equation followed by world population ( P), past and present: P = A/( D - t) M , where t is time and A, D, and M are constants. Cumulated historical population estimates confirm this hyperbolical pattern first noticed by Cailleux, Meyer, and Foerster. Technological indices should grow according to the same pattern; partial confirmation of this part of the model is presented. The growth acceleration crisis that we are now facing may have had a counterpart around 4500 B.C., during the neolithic agricultural revolution. World-population projections up to 2000 A.D. are discussed in the light of the interaction model, with and without resource limitations.