Birth Rates and Population Projection Issues
Demographic Issues
This is a summary of the essays in this blog on demographic projections.
It is not only the arc of population increases and then decreases that is important. It is what happens under the arc. Birth rates fall below replacement, the number of births go down, the size of the labor force decreases while the number of retired people go up. Eventually, the number of older citizens start to go down and the total population decreases faster and in larger numbers. This scenario happens in an increasing number of countries and then for the global population.
The demographic projections and discussion in this blog are based on the Lancet projections of birth rates and population using 2017-2020 data. Forecasts for global trends and for some countries have changed since the Lancet projections. The key projection is birth rates for each country, for geographical regions, and for the entire world.
But how good are estimates of future birth rates and population projections? In the Lancet study, both birth rates and population projections come with wide 95% confidence intervals.
For some countries the birth rates now are lower than forecasted or are falling faster than expected. The general trend is that the global population will reach its maximum earlier than expected, which is currently in the 2060s.
For many decades a country could have a low birth rate (below replacement) but increased population because of longer life expectancies. This could continue for a long time. China has had extremely low birth rates since 1980 but their population only began to decline in 2022. Japan’s birth rate fell below replacement in 1974 but population began falling in 2008.
It is important to emphasize that long-term projections could change for unknown reasons – new conception technologies, new medical technologies to greatly lengthen life expectancies, environmental or economic collapse, and other unknowns.
How Birth Rates are Computed
There are different ways to measure a country’s birth rate. The most common, and probably most useful for trends, is the total fertility rate (TFR).
The total fertility rate is the average number of children a woman would have during childbearing years. It is calculated by summing the different fertility rates (births per 1,000 women) in specific age groups, usually five years. It assumes the current age-specific fertility rates. A TFR of 2.1 is the child replacement level needed for a stable population.
One complication is a recent pattern in age-specific fertility rates. Since 1990, in the United States, there has been a large decrease in the birth rates of teenage women and women in their twenties, now well below replacement. But the overall birth rate until Covid remained fairly stable at or slightly below replacement. The main reason seems to be that many women were delaying having children until their thirties and forties. Birth rates in these age groups shot up, countering the falling birth rates of the younger age cohort. During Covid, the overall birth rate fell and has not recovered. It is too early to tell if this is a delayed function of Covid or a permanent shift in the fertility rates of older women.
Why do birth rates go down? Different reasons for different countries. Some common denominators are access to birth control, urbanization (rural to urban internal migration), higher education for women, changing expectations, and the high cost of raising and educating children. In the past, a falling birth rate was correlated with industrialization and rising real incomes. This is not true in many poor countries, notably in Africa.
Population Growth and Changing Age Distribution
Population growth or decrease for a year is simply deaths minus births plus net immigration. Net immigration may be negative, as it is for many Balkan countries, as for Haiti, Cuba, and Venezuela recently.
Demographically, the world is divided into two groups. The outside of Africa group collectively has a below replacement birth rate; Africa has an above replacement rate. For the world as a whole, the birth rate is 2.3. How fast it falls depends mostly on how fast birth rates fall in Africa.
The world outside of Africa has mostly below replacement birth rates or falling birth rates at or near replacement (India). Birth rates in China, Japan, Southeast Asia, and large parts of Europe have very low birth rates. Total populations are falling or will start falling soon. In contrast, Africa has the highest birth rates in the world. They are falling but are still well above replacement. With longer life expectancies, Africa is facing large increases in population over many decades.
Globally, life expectancies have risen rapidly since 1950. Change in the age composition of a country is important. More countries will go through a period where the total population is going up but the number children and people in working ages, usually 15-64, is going down and 65 and over is going up. The number of births goes down. Eventually, deaths from an increasing number of older residents are greater than births and the total population falls. This implies different social policies and different economic effects at different times in this cycle.
These trends in changing age composition and longer life expectancy are important for such topics as economic growth and financial support for retirement and healthcare programs for the elderly. Most industrialized countries have low rates of economic growth and taxable income, and the increasing expense of the rising number of senior citizens. This combination is one reason almost all countries’ federal budgets have been running yearly deficits; their total national debt is rising. Interest expense on the national debts is rising faster than overall expenditures or tax revenue. Will governments in the future be able to pay for the increasing costs of supporting their growing retirement population?
Immigration
Population change is also affected in some countries by emigration or immigration. Emigration out of some Eastern European countries (combined with low birth rates) is leading to large population shrinkage. A country could have substantial immigration without influencing the number of births if the immigrants are on temporary work permits and segregated from the native population, as in the Gulf States and Singapore. These types of immigrants usually have little chance of becoming permanent residents or citizens, or forming families. On the other hand, over 25% of Germany’s population has at least one immigrant parent. About half are citizens. The other half had good prospects to become permanent residents or citizens before the rise of an anti-immigration movement similar to that of the United States.
As the number of immigrant workers rise, the birth rate could remain the same, or go down, while the population increases. Immigrants replace some of the decrease in working-age population. In Japan, for example, the increase in immigrants (on temporary work permits) over the last ten years has been about the same as the decrease in the prime working age population. This might not continue because of the political backlash against increased immigration.
Japan was increasing immigrants, under a regulated system, to replace the fall in the number of the native-born work force. These immigrants tend to be given jobs in areas of the economy Japanese workers avoid – farming, fishing, construction, tourism, services for the elderly.
What does it mean for a country if the decrease in population because of the decrease in the number of workers is made up of immigrants from other countries on temporary work visas?
Different countries are at different stages of the demographic cycle. Three examples are given below. Some countries, clustered in Europe and East Asia, already have declining populations. The United States is rather a special case. Poorer countries, many of which are in Africa, find it difficult to deal with economic and political problems because of high birth rates and high rates of population growth.
First Example: China (long-term very low fertility)
This is one of the two most dramatic population projections: If China’s birth rate stays at its very low rate, China’s population will go from 1.4 billion currently to around 750 million in 2100!
China has had a very low birth rate since 1980, the beginning of the one child policy. Even when it was abandoned, the birth rate stayed very low (maybe even lower). And because of abortions and infanticide during the 35-year period 1980-2015, there are an estimated 30-40 million fewer women in child-bearing ages groups than there would have been otherwise. The number of births continue to fall. But life expectancies rose rapidly as China had internal peace and rapid industrialization. China’s demographic future will see fewer births and more deaths per year, widening the gap. The annual decrease in population, only about 3-4 million per year at the present, will increase.
But because of better health care and higher standards of living, Chinese are living longer. With a very low birth rate and longer life expectancies, the Chinese population is aging faster (average age, percent of population over 60) than any other country in the world.
Second Example: The United States (immigration-dependent population growth)
Until Covid and the recent changes in immigration, the United States seemed to be looking at slowly growing population with a gradual shift in the age structure. The birth rate was at or slightly below replacement.
For the United States, the possible changes in population projections are dramatic. Birth rates fell below replacement during Covid and have not recovered. Recent policy changes have reduced immigration. Deaths are expected to equal births in 2031 (latest Congressional Budget Office estimate). Any population increase will come from net immigration (immigrants minus emigrants).
In the past, immigrants were younger and had a higher birth rate than native-born Americans. This might suggest the current below replacement birth rate will stay low or go down.
Until recently, the large number of immigrants into the United States since the 1960s had a good chance of becoming permanent residents (green cards) or citizens. Over the last few decades, immigrants have accounted for most of the increase in births and most of the increase in the total population of the United States. Only a few years ago, projections, which assumed continuing high rates of immigration, placed US maximum population as far out as in the 2060s.
The over-65 population of the United States is expected to double in about 25 years. Social Security and Medicare trust funds, which pay for part of current expenses, are expected to run out around 2033. It is likely the deficits in these two programs will be covered by funds from the general expense budget. This would probably increase the yearly budget deficits and the subsequent national debt. Already, interest on the national debt is about equal to expenditures on national defense.
Like the United States, many countries are facing large yearly budget deficits and increasing numbers of citizens on pensions and requiring public health care support.
Third Example: Nigeria (poor country with high fertility without per person income growth)
This is the other dramatic population projection: If Nigeria’s birth rate does not fall faster than projected, Nigeria’s current population of around 240 million will rise to around 700 million by 2100!
The ten countries with the highest birth rates in the world are all in Africa. They all have birth rates higher than Nigeria.
Nigeria is the most populous country in Africa. It has had one of the world’s highest birth rates since becoming independent in 1960. Its birth rate is falling but is still far above replacement. Its largest city, Lagos, has over 30 million people. It has a rapidly growing population but real per capita income is very low and not rising. In addition, it has many social and political problems that will make it difficult for Nigeria to accelerate economic growth without major changes.
Nigeria’s problems are representative of many countries in Africa, the Middle East, and South Asia.
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An important point is that changes may take decades to play out. After World War II, there was a population explosion. Books were written in the 1960s and 1970s warning of global catastrophe based on overpopulation. But the factors listed above that lowered birth rates were working. Effective contraception became widely available. Innovations in health care extended life. Future technological innovations, particularly in the health care industry, could impact future birth rates and life expectancies.
Countries have time to start planning for the effects of a declining population. Some of the most difficult consequences might be psychological. A society where most families don’t have children? A society whose culture is dominated by old people? Depopulation of rural areas, which leads to economic and social collapse of these areas. This is already happening in many countries, including the total abandonment of a few villages in southern Europe. What happens to the massive investment in infrastructure, information technology, and housing? Already, Japan has eight million abandoned houses.
One response to the fall in the number in the working-age cohort is specialized AI models for white collar jobs and AI-enhanced robots for blue collar jobs. Already, Amazon projects a large increase in its use of robots and a decrease in human employees. Before any decrease in human employees due to autonomous-driving delivery vehicles and possible drone delivery.
Why Does It Matter?
The long-run population projections point to a potentially dangerous future world. By 2100, virtually every country outside of Africa will have declining populations. Many will see about 50% fewer people. In contrast, Africa will reach a point of slowly increasing total population after a period of a massive increase in population. Even if governments are less dysfunctional and economic growth rates are much higher in Africa than they have been over the last 60 years, much or all of the increase will be matched by population growth. Real per capita incomes will not go up or go up very little from current extremely low levels. Africa’s future partly depends on how fast the continent’s birth rates fall.
There are long lags between the start of below replacement birth rates and declining population. China’s birth rates fell below replacement starting with the “one-child” policy in the early 1980s and the beginning of declining population in 2022. Japan’s birth rate fell below replacement in 1974 and population only began declining in 2008.
For years, the decline in population is small compared to the total population. But the decreases get larger over time. It is easy for countries and their political leaders to ignore the future consequences of population decreases.
Besides trying to document and analyze these trends, the demographic essays on this blog also try to see how these trends interact with other parts of societies. Immigration policy is already a major issue in many countries. Some others are economic growth and development, financing the pensions and healthcare of the elderly, and redundant infrastructure such as abandoned schools and housing. There also might be psychological and social costs in a society of few children and many older residents. There may be social segregation by age, at least in rich countries. Demographics may also interact with the other global challenges such as the competing costs and effects of global warming.
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