New Delhi: A new study published in The Lancet has found that improvements in access to modern contraception and the education of girls and women are generating widespread, sustained declines in fertility, and that world population will likely peak in 2064 at around 9.7 billion, and then decline to about 8.8 billion by 2100, which is 2 billion lower than some previous estimates. 23 countries will see populations shrink by more than 50 per cent, including Japan, Thailand, Italy, and Spain.
The researchers used data from the Global Burden of Disease Study 2017 to project future global, regional, and national populations. The researchers of the study, who are from the Institute for Health Metrics and Evaluation (IHME), used novel methods for forecasting mortality, fertility, and migration, and estimated that by 2100, 183 of 195 countries will have total fertility rates (TFR) below 2.1 births per woman. TFR represents the average number of children a woman delivers over her lifetime. This implies that the populations in these countries will decline unless immigration compensates for the low fertility, the study said.
The new population forecasts highlight the huge challenges to economic growth of a shrinking workforce and the high burden on health and social support systems of an ageing population. It also highlights major shifts in economic power.
There will be huge shifts in the global age structure, the study predicted. The number of individuals aged above 65 years of age will be 2.37 billion in 2100, while the number of persons below 20 years of age will be 1.7 billion. Since there is a significant decline in working age populations, countries need to implement liberal immigration policies, the study said. This is because such policies could help maintain population size and economic growth even as fertility declines.
Dr Christopher Murray, who led the research, said the study provides governments of all countries an opportunity to start rethinking their policies on migration, workforces, and economic development to address the challenges presented by demographic change, according to a Lancet statement.
Professor Stein Emil Vollset, first author of the study, said the findings suggest that the decline in the numbers of working-age adults alone will reduce GDP growth rates that could result in major shifts in global economic power by the end of the century.
Total Fertility Rate Predicted To Decline Steadily
The study estimated that the global TFR will steadily decline from 2.37 in 2017 to 1.66 in 2100, which is well below the replacement level fertility set by the United Nations Population Division. An average of 2.1 children woman is considered necessary to maintain population numbers. Rates are predicted to fall to around 1.2 in Italy and Spain, and become as low as 1.17 in Poland, the study said.
People Aged Above 80 Will Outnumber Those Aged Below Five
The number of children below five years of age is forecast to decline by 41 per cent from 681 million in 2017 to 401 million in 2100, the study said. There will be a six-fold increase in the number of individuals older than 80 years, from 141 million to 866 million, the study predicted.
If labour force participation by age and sex does not change, the global ratio of non-working adults to workers is projected to increase from 0.8 in 2017 to 1.6 in 2100.
Major Shifts In Size Of Economies Due To Declining Working-age Populations
The study predicted that rapid population decline 2050 onwards in China will curtail economic growth in the country. The study said that USA is expected to reclaim the top spot for annual gross domestic product (GDP) by 2098, given that immigration continues to sustain the US workforce.
The authors warned in the study that response to population decline must not compromise progress on women’s freedom and reproductive rights.