The declining birth rate of any social group, especially a country as a whole, threatens the survival of its culture in its expansionist form. It has more immediate implications in terms of the proportion of active workers available to support those of pensionable age. Shifts in the size of age groups also have severe implications for the future of particular businesses and services, notably those for young people.
Over the past century, beginning in Western Europe and North America, a rising proportion of women have entered higher education and the skilled labor force. Improved education has also given women greater autonomy within relationships, a better understanding of contraception, and greater input into family planning. Many have opted to delay becoming mothers in order to pursue their careers. And the opportunity cost of having children increases as women’s wages rise relative to their male partners. Paradoxically, many women of prosperous societies would like to have more children but are now constrained by economic factors quite different from their mothers and grandmothers.
Several countries are experiencing steep population declines, most notably Japan, where projections from the National Institute of Population and Social Security Research (2015) are that the Japanese population will fall by 900,000 a year, reducing the nation’s population by one-third by 2045.
Russia expected to be down to 111 million citizens by 2050, a drop from 143 million in 2018, although that might have as much to do with high mortality rates as with low birth rates. Though Russian fertility rose in the decade after 2000, the total fertility rate (TFR) never even got close to 2, and has slumped back to 1.5.
In 2023, South Korea's total fertility rate (TFR) was estimated to have been 0.72. In Europe there was no longer a difference between Roman Catholic and Protestant countries: Italy’s TFR (1.21) was lower than England’s (1.44). Nor was there a difference between Christian and Islamic civilizations.
The timing of this huge demographic transition has varied. In the USA, the decline in birth-rate started in 1957, four years before the pill became available and the TFR fell below 2.0 in 1973. In the UK, it happened a year later; in Italy in 1977. The East Asian countries were not far behind: In South Korea TFR was above 2.0 until 1984; in China until 1991. Fertility remained higher for longer in the Muslim world, but it fell below 2.0 in Iran as early as 2001. Even in India, in 2023 the TFR has now fallen below 2.0.
The current worldwide tendency for actual population decrease or reductions in rate of increase may help developing countries raise their living standards, but will also require adjustments in both developed and developing countries, particularly in providing security to the elderly. This will be even more the case by the 21st century. Nations will experience a marked reduction in the number of children entering the age group of compulsory schooling and, progressively, in that of the age groups entering universities, military service, and growing up to be productive members of society in terms of both wages earned and ideas/creations returned to society.
One must immediately add that in the northern hemisphere the nature of this problem is reversed: here, the cause for concern is the drop in the birth rate, with repercussions on the aging of the population, unable even to renew itself biologically. In itself, this is a phenomenon capable of hindering development. Just as it is incorrect to say that such difficulties stem solely from demographic growth, neither is it proved that all demographic growth is incompatible with orderly development. (Papal Encyclical, Sollicitudo Rei Socialis, 30 December 1987).
Low birthrates are infinitely more dangerous to aging industrial societies than smoking or "mad cow" disease. They must choose: pronatal policies, immigration, or slow death.
What are the drivers of the great fertility slump? One theory is that societies progress up the hierarchy of needs from physical survival to emotional self-actualization, and as they do so, rearing children gets short shrift because people pursue other, more individualist aims. People find other ways to find meaning in life. Another interpretation gives the agency to women, emphasizing that fertility drops as female education and employment rise.
Any decline in population growth is a relief on already overstrained planetary resources.
Birth rates increase and decrease over long periods of time. To be concerned about declining birth rates over a period of less than 50 years is short sighted.
The reasons are complex. Prosperity often leads to lower birth rates. So do urbanization and industrialization. So do advances in medical science. So, too, does the empowerment of women. In fact, lower birth rates are clear indications of well being. High birth rates often indicate the opposite.