Introduction to Demographics and Global Population Projections
Much of this is taken from the summary of the longer and more detailed
This is a summary and overview of the demographics and population projection essays on this blog (links below). The world is at the beginning of a major shift in population, from large population increases since 1950 to decreasing populations in many countries and, in the long run, in the world as a whole. This historical shift in global and national populations will have a big influence on what happens in the future.
In summary,
· Huge population increases since 1900, especially after 1950.
· Because of a big decrease in birth rates, global population will increase until the 2060s and then start to decrease.
· Some countries are already seeing a population decrease. More will follow in the near future. Population decreases will accelerate.
· These two trends will have a big effect on all other changes - economic, political, environmental.
Think of the world as divided into Africa and Not-Africa (rest of the world). Between now and sometime in the 2060s, the increase in population in Africa will be greater than the decrease in population in Not-Africa. From the 2060s to 2100, the decrease in population in Not-Africa will be greater than the slowing increase in population in Africa.
DEFINITIONS AND BIRTH RATE PROJECTIONS
Demographics is the study of populations and how a population breaks down by age, gender, race, and other variables.
There is one concept that is crucial for population projections:
Total Fertility Ratio (TFR). This is the ratio of the average number of children of women in child-bearing ages. For a population to be stable, women must have an average of 2.1 children each. Any smaller number means the population is “below replacement” and may decrease in the future.
The global birth rate (total fertility rate) is now about 2.3, slightly above the replacement rate of 2.1, and falling. How fast it falls depends critically on how fast it falls in India and in Africa.
The global Total Fertility Ratio (TFR) is forecasted to be 1.7 in 2100, well below replacement. Currently, the lowest birth rates in the world, at around 1.0, are in East Asia – China, Japan, and South Korea.
A population may have below replacement birth rates and for some time also have expanding population if in the past it had above replacement birth rates, a large percent of its population were children and young adults, and the adult population is experiencing rising life expectancies. Or, the decrease in population is offset by immigration.
Total populations eventually fall, as the number of children fall, the number of adults below 65 fall, and then the number of senior citizens fall. A birth rate below replacement will lead to fewer children. Then it will lead to a smaller working-age population (18-65). And finally, a smaller over-65 population.
GLOBAL POPULATION IN THE PAST
Since the beginning of the Agricultural Revolution (farming and domesticating animals) about 10,000 years ago, demographics meant high birth rates, high infant mortality rates, low life expectancies, and high death rates. The world’s population didn’t change very much until the Industrial Revolution, starting in the late 1700s. Death rates fell faster than birth rates; better health and health care reduced infant mortality rates.
At the same time, much of the world’s population experienced rising standards of living. Better public health reached poorer parts of the world. Urbanization, which lowers birth rates, greatly expanded. Better education, especially for females, is correlated to falls in birth rates. One consequence was longer life expectancies and rising average ages in industrialized countries and then in poorer countries. The age composition of the global population changed, as the average age of the populations in most countries started rising.
During this transition period, from the late 1800s to the present, average life expectancies increased from roughly 30 years to 75-80 years in industrializing countries.
Global population:
1900 – Approximately 1.6 billion people
After World War II, the global population exploded:
1950 – 2.6 billion
2024 – 8.0 billion (November, 2023)
The global population has more than doubled since 1970, going from 3.7 billion people to the current (November, 2023) total of 8.0 billion (UN numbers).
The period from 1950 to 2000 was unusual. Not just in the United States, the global population experienced high birthrates and high population growth rates. In the middle of this period, partly due to more effective and more available birth control, birth rates began declining in the industrialized countries. The growth rate of the world population began to slow.
POPULATION PROJECTIONS
The global population is projected to be:
2064 – 9.7 billion (the peak global population)
2100 – 8.8 billion
By the 2060s, the global birth rate will be below replacement. Over the next 40 years (2025-2065), the world’s population will rise by about 1.7 billion and then over the 35 years after that, decline by approximately 0.9 billion (900 million). By 2100, the global population will have fallen to 8.8 billion.
By 2050, 151 countries (out of 192) are forecasted to have a birth rate lower than the replacement rate (<2.1). 23 countries are forecasted to have population declines greater than 50%by 2100. China’s population is forecasted to decline by 48%, from the current 1.4 billion to about 750 million in 2100.
Compared to the present, Africa is expected to have about 2.2 billion more people in 2100. The rest of the world is expected to see a decrease of about 1.4 billion people. One billion of the decrease will occur in China (about 750-800) and India (about 250-300). The rest of the decrease will occur mostly in Europe, southeast and southern Asia, and Japan. The United States and Latin America (because of increasing population in Mexico) will see littlechange. But the US may be at the beginning of the downward population curve if the recent trends of a below (and falling) replacement birth rate and a decrease in net immigration continue.
About 500 million of the African increase will happen in Nigeria. (See later essay) Nigeria’s population growth will be so great that by 2100 the country may pass or equal China as the second most populous country in the world.
The global population is aging, with the over-65 age group becoming a larger percent of the total. By 2100, there will be 2.4 billion individuals older than 65 years compared to 1.7 billion individuals younger than 20 years.
The industrialized and modernizing parts of the world now have low birth rates – mostly below replacement – and low death rates. Birth rates are also falling in much of the rest of the world.
Declining population is already true in Japan, China and Russia, and is about to be true for most of Europe and much of Southeast Asia.
As the population and the labor force of a country decrease, it is possible that income per capita will continue to rise for a generation or two. But in the long run, income per capita will probably fall.
It is nearly impossible to predict technological and organizational change over the next 25 or 50 years. This will help determine if increases in productivity will counter the decrease in the size of the working population. This raises questions about the role robots in manufacturing and distribution (Amazon warehouses) and AI models in offices will play in the future. Robots are used more in countries with a declining number of employees now or in the near future (Japan and China).
GLOBAL DEMOGRAPHICS
Outside of Africa, the global birth rate is already below replacement but longer life expectancies will lead to continued population growth for one or two generations. Some countries already have declining populations.
Countries with over a third of the world’s population and most of the world’s output now have birth rates below or at replacement. They are mostly the wealthy, industrialized countries, including the United States, Canada, Brazil, Western and Central Europe, Turkey, parts of Southeast Asia, Japan, Russia, and China. Collectively, the size of their workforces has stopped growing. India, the exception, has a birth rate slightly above replacement but it is falling. This will add another 17% of the world’s population that has a below replacement birth rate.
There are falling birth rates for most of the rest of the world’s population, coming down from very high levels. But total population continues to grow, partly because of lower infant and child mortality rates, public health programs, better medicine, and longer lives in most of the world.
Regardless of what happens to the size of the labor forces in individual countries, the size of the global labor force after around 2100 will start to fall. An important question may be how it is allocated by migration.
GLOBAL FORECASTS
We are now in a period of a slowdown in total population growth rates. Global population is growing at about one percent per year and the rate continues to fall. But the increase in the number of people is large.
Changes in total population may be points on an exponential decay curve. The decline in numbers after achieving the maximum number of people in the 2060s will depend on how fast the African birth rate falls. Countries with birthrates well below replacement and aging populations may experience accelerating decreases in population.
The rate of decline could change with changes in the availability and cost of birth control, anti-aging medical technologies and more available health care for an aging population.
A big unknown is future medical technology that prolongs life expectancies. Technological advances might also decrease medical costs per capita. Regardless of the projections, the fastest growing age cohort in the foreseeable future is 80 years and older.
Countries with birthrates well below replacement and aging populations may experience accelerating decreases in population.
POOR COUNTRIES AND RICH COUNTRIES
Wealthy countries have below replacement birth rates, no growth or declining populations and labor forces, low real economic growth, and aging populations and labor forces. Population will continue to concentrate in cities; the population of a small number of cities will be responsible for technological innovation and economic development. Rural areas will continue to lose population.
Africa and a few poor countries outside of Africa will have the opposite problem. They will have above replacement birth rates for a generation or two. This will lead to high growth rates in labor force age groups and total population. Whether or not this will translate into high economic growth rates is problematic, depending on many other factors. These countries could be a source of large immigration to richer countries.
Many poor countries have poor infrastructure, poor education and health facilities, diseases, parasitic and corrupt political elites and bureaucracies, military coups, and internal violence including civil wars for political control. As an example, the next essay I will send you is a quick look at Nigeria.
All countries will sooner or later face the same challenges: With declining populations and smaller labor forces, will they be able to invest in economic growth and development (innovation and structural change), deal with environmental costs and climate change, and support aging populations?
(DISCLAIMER: MY LAWYER FORCED ME TO ADD THIS)
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