The Unnoticed Change--Living on the Knee of the Curve: Declining Birthrates are Leading to Declining Population

The Unnoticed Change

Living on the Knee of the Curve: Declining Birthrates are Leading to Declining Population

Figure 1: Recreation of a Neolithic Settlement (Strom, 2018)

The Neolithic Revolution

Perhaps the most substantial change in human society since the Neolithic Revolution is happening before our very eyes. Few have noticed. It is possible to see this change as being driven chiefly by the return of human society to a social condition thought to exist before the Neolithic revolution: equal social status of women and men.

Current evidence suggests that the Neolithic Revolution began about 12,000 years ago. It was the transition over thousands of years of the bulk of humanity from a nomadic, foraging lifestyle to a settled lifestyle dependent upon agriculture. Anthropologists call this settled lifestyle sedentism. Figure 1 is a recreation of a neolithic settlement.

Many crucial changes in human society are associated with this transition. It coincided with the development of larger human social groups, and was thus an important step leading to the development of the concept of property, and eventually of money, as well as the development and spread of written language.

For about two million years, our nomadic, foraging ancestors seem to have lived in small bands, typically of around 100. Some of these bands may have been as large as 300. These bands traveled frequently; men and women shared work equally; there was no apparent specialization. While males might have been more likely to hunt and females to gather, there is evidence of numerous exceptions even to this pattern. Females had three to four children over a lifespan. They were spaced well apart by a lifestyle that relied upon near-constant movement. Two to three of those children likely lived to adulthood. While accidents and predators killed some early, many of these people lived into their seventies or even longer. Constant movement and the variety of their diet contributed to keeping them healthy. Over these two million years, the population grew only gradually. Even the modern human population grew relatively gradually until very recently. Figure 2 shows the global human population over the last 12,000 years.

Figure 2: Global Human Population: 10000 BCE to 2021 (Roser, et al., 2013)

Sedentism brought about increased food security, and then gradually increased settlement sizes. However, it also resulted in decreased nutritional variety and quality, decreased quality of life, and decreased life expectancy. Class differences, along with individual wealth and poverty, eventually came about through sedentism. The close quarters of increasingly larger settlements and the hygiene problems associated with living in crowded groups led to increased disease. Nonetheless, it would be a mistake to romanticize our egalitarian hunter-gather past. We cannot live there, but only in our present.

Dependence on agriculture also brought about increased dependence on child labor to tend the animals and the fields of larger and larger farms. The average number of births per woman over a lifetime (known as the total fertility rate or TFR) increased dramatically. Those births were much closer together than the births of our nomadic ancestors. As a result, women of sedentary societies were exposed to an increased risk of death in childbirth. The direct contributions of women to the economic output of the family were seen as less than those of men over time. Women became increasingly valued for the number of children that they birthed. Whether or not women contributed less is debatable and not a subject to be pursued here. While the social status of women has been much lower than the social status of men for nearly all of recorded human history, that is seemingly not true of our unrecorded, pre-sedentary past.

Hygiene and Disease

As we are relearning today, living closely together in large groups makes it extremely easy for communicable diseases to spread. This was not a problem for our nomadic ancestors. If a disease did happen to infect a nomadic band, it was unlikely to spread to another because bands interacted with each other infrequently. Diseases had only a very limited pool of potential targets and were very likely to die out quickly.

Living together in larger and larger settlements changed the dynamics. It made it much easier for disease to spread by presenting a far larger pool of potential targets. Furthermore, poor public hygiene spread disease through infected water, food, and waste. These conditions were not a problem for small bands which moved frequently. As a result, life expectancy decreased as settlement sizes increased.

For thousands of years, the higher death rates which resulted from settled living served as a brake on human population growth despite higher birth rates. Consequently, the population still grew relatively slowly. Eventually, that would change.

Trade, Specialization, and Industrialization

Even those foraging societies that have continued to exist into recent times are known to trade goods over relatively large distances. However, they primarily trade raw materials required for making tools and prestige goods. Prestige goods serve only to elevate the social status of those who possess them, whether they are individuals or communities.

Over time, sedentary societies, due to their increased food security and their decreased nutritional variety, were motivated to trade economic goods, in addition to prestige goods. While economic goods may, and usually do, impact prestige, they also serve to improve the quality of life in some way. Economic goods include spices, desirable foods, desirable fabrics, and other transportable goods. The growth of trade increased specialization within sedentary societies and enabled further growth of settlements. It also served to increase the transmission of many diseases.

Around 1700 CE, gradual improvements in public hygiene, medical knowledge, and diet (through increasing transportation of a variety of foods) began to decrease death rates and increase life expectancy. The human population had entered an age of exponential growth.

There were an estimated 4.4 million humans at the beginning of the Neolithic Revolution. It took about 3,000 years for that number to double to an estimated population of 9.6 million humans. Over the 3,000 years that followed, the population would triple, to 28.8 million. Over the next three thousand years, it would nearly quadruple to 110.4 million. It would more than double again in the following 1,000 years to an estimated 232.1 million at 0 CE. Over the subsequent 1700 years, it would increase another 2.5 times to nearly 600 million humans. Over the 11,700 years between the beginning of the Neolithic Revolution and 1700 CE, that represented a 54.5 fold increase in the global human population. If that seems amazing, it was nothing compared to what was coming. Over the 321 years since 1700 CE, the global human population has increased another 13 times to 7.8 billion. The human population has grown 8.7 times faster over the last 321 years than it did in the 11,700 years before that. (Roser, et al., 2013)

However, as cities began to grow, the economic pressure on women to have many children began to ease. In those cities (initially built around trade, later around industrialization, and now around services and knowledge work) having many children was no longer economically beneficial to a family. Human society shifted from dependence on child labor to the increased education of children. As a result, the social and economic costs of having children increased.

It appears that birth rates first began to fall from their agricultural peaks in France over the eighteenth century, just as the population began exponential growth. However, the initial decreases in TFR were modest. The TFR began to fall more consistently in France around 1800 and in the rest of Western Europe around 1870. (Wrigley, 1985) Since then, birth rates have continued to fall in Europe and the pattern of decreasing TFR has spread from society to society across the globe. According to the Population Reference Bureau (PRB), the global TFR has fallen from 3.2 in 1990 to 2.3 today. (Population Reference Bureau, 2021)

As the TFR has fallen over the last 300 years, women have become increasingly educated, increasingly involved in work outside the home, and increasingly involved in other aspects of public life. Consequently, while the social status of women is still well below that of men in many societies, it has tended to increase in most societies as TFR has decreased.

Current Population Trends

A TFR of approximately 2.1 is necessary to maintain a stable population, this is called the replacement rate. The replacement rate is 2.1 in most modern societies, rather than 2.0, to account for child mortality. A TFR less than the replacement rate signifies a declining population, a TFR greater than the replacement rate, a growing population.

The PRB reports a current TFR of 1.6 (well below replacement rate) for the U.S. This is consistent with the recent 2021 U.S. Census Bureau Population Estimate showing the slowest population growth in U.S. history. (Rogers, 2021) The U.S. population grew at all only due to immigration. The recent TFR of the European Union has been as low as 1.4, but seems to be stabilizing at about 1.5. The TFR in China is controversial. As a result of the one child policy, it fell well below the replacement rate. The Chinese government and the World Bank currently report it as 1.7. The CIA reports it as 1.6. Some other sources report that it is as low as 1.1. (Chang, 2021) A TFR of 1.1 to 1.2 would be consistent with other wealthy East Asian countries including Hong Kong, South Korea, Singapore, Macau, and Taiwan.

The CIA’s current World Factbook (US Central Intelligence Agency, n.d.) lists TFR as still at or above the replacement rate in 96 of 227 countries. These countries are primarily in Sub-Saharan Africa, and South, Southwest, and Central Asia. While, TFR has been continually decreasing in all parts of the world, it is generally lowest in the highest income countries and generally highest in the lowest income countries. Nonetheless, while the U.N. projections are more conservative, the projections of the Institute for Health Metrics and Evaluation at the University of Washington are that TFR will be below the replacement rate in nearly all countries by the end of the current century and that the global TFR at that time will be 1.6–1.7, well below the replacement rate.

Declining populations are already leading to economic problems in some parts of the world. Efforts to motivate increased fertility in a number of nations experiencing declining populations have been unsuccessful. They have so far produced only marginal to no increase in fertility. It appears that the social forces leading to below replacement rate fertility are resistant to manipulation by governments.

The population of the Russian Federation peaked in about 1990 and after a small bump up to a lower peak from 2010 to 2020, is now projected to enter a steady decline. The total population of Central Europe, Eastern Europe, and Central Asia shows the same pattern even though the Central Asian nations are projected to grow collectively in population by 45 million people between now and the end of this century. (Institute for Health Metrics and Evaluation, 2020) It should be noted that the area of Eastern Ukraine that is currently threatened with invasion by the Russian Federation is both heavily industrialized and nearly exclusively ethnic Russian in heritage. A Russian invasion would serve both to increase Russia’s industrial base and its ethnic Russian population.

Future Impacts of Below Replacement TFR

If the current global trends in TFR continue, the global human population will peak somewhere between 2040 and 2060 and then begin to decline indefinitely. Figure 3 shows projections of the global human population between 1960 and 2100 for several possible scenarios.

Figure 3: Global Human Population: 1960 to 2100 (Institute for Health Metrics and Evaluation, 2020)

At the end of this century, the populations of China, Japan, Eastern Europe, and Russia may be approximately one-half to two-thirds of what they are today. India will be the world’s most populous nation. Nigeria, currently the seventh most populous nation, is likely to be second-most populous. China will drop to the third most populous unless Nigeria’s TFR drops more rapidly than forecast. The U.S. will likely drop to fourth depending on how it approaches immigration going forward. If the U.S. further restricts immigration and the TFR of Brazil and/or Pakistan decrease more slowly than forecast, the U.S. could drop from its current position as the third most populous to fifth or sixth.

The economic and political power of these nations will shift with the shifts in population. India will supplant China as the world’s economic engine. China and Russia may well become even more aggressive, both politically and militarily, as they seek to remain major players on the world stage despite dramatic population declines. Sub-Saharan Africa, led by Nigeria, will ascend in economic and political importance. The Western European Culture which has dominated global society for the last 500 years will very likely struggle to maintain that dominance. We may be seeing signs of that already in challenges by China and discord in western societies, particularly the U.S.

The economic changes caused by declining populations and a declining global workforce will be major, some predictable, some unpredictable. The current labor shortages seen as a result of the SARS CoV2 pandemic, are minor compared to those that will result from a rapidly shrinking and aging workforce. Pressure to decrease specialization will appear as the workforce decreases in number. Pressure to adopt automation will only increase. The ability of the economy to adapt will depend upon whether or not automation can keep pace with workforce declines. Wages will likely rise to reflect the increasing scarcity of workers.

The transition to a declining human population will produce opportunities, as well as challenges. We will eventually have the opportunity to return developed land to natural habitat. We should be planning for that. While, eventually, the lesser population will strain the planet’s resources less, we must continue with steps to minimize human impact on the climate. It will likely be more than a century before population decline alone aids in that effort. Cities may become less crowded, depending on how the declining population interacts with increasing urbanization.

Many unforeseeable changes in human society will result from this transition. We should be thinking about how to take advantage of the transition, and the following decline in population, to make a world that better reflects humane values. We know that the future will be much different from the past, even the recent past. However, humans have the unique ability to adapt our environment to ourselves as well as to adapt ourselves to our environment. Humans are uniquely able to create any future that we can imagine if enough people work together. If we truly desire to create a better future for our children’s children, we must become not only aware of, but educated on, the many aspects of human culture that should be improved. The period of change that is already upon us affords us a unique opportunity to imagine and to create a better future. Those who understand what is coming will be in a position to influence the outcome of this period of revolutionary change.

References

Chang, G. G. (2021, March 23). The Coming Demographic Collapse of China | The National Interest. The National Interest. Retrieved January 11, 2022, from https://nationalinterest.org/feature/coming-demographic-collapse-china-180960

Institute for Health Metrics and Evaluation. (2020, July 14). Population Forecasting | IHME Viz Hub. Institute for Health Metrics and Evaluation. Retrieved January 11, 2022, from https://vizhub.healthdata.org/population-forecast/

Population Reference Bureau. (2021). 2021 World Population Data Sheet. Population Reference Bureau. Retrieved January 11, 2022, from https://interactives.prb.org/2021-wpds/

Rogers, L. (2021, December 21). U.S. Population Grew 0.1% in 2021, Slowest Rate Since Founding of the Nation. United States Census Bureau. Retrieved January 11, 2022, from https://www.census.gov/library/stories/2021/12/us-population-grew-in-2021-slowest-rate-since-founding-of-the-nation.html

Roser, M., Ritchie, H., & Ortiz-Ospina, E. (2013). World Population Growth. Our World in Data. Retrieved January 11, 2022, from https://ourworldindata.org/world-population-growth

Strom, C. (2018, June 30). From Hunters to Settlers: How the Neolithic Revolution Changed the World | Ancient Origins. Ancient Origins—Reconstructing the Story of Humanity’s Past. Retrieved January 12, 2022, from https://www.ancient-origins.net/history-important-events/neolithic-revolution-0010298

US Central Intelligence Agency. (n.d.). Total fertility rate — The World Factbook. The World Factbook. Retrieved January 11, 2022, from https://www.cia.gov/the-world-factbook/field/total-fertility-rate/country-comparison

Wrigley, E. A. (1985). The Fall in Marital Fertility in Nineteenth Century France. European Journal of Population / Revue européenne de Démographie, 1, 31–60. https://doi.org/10.1007/BF01796917