This document analyzes global demographic aging, focusing on population age structures and growth projections from 1950 to 2100, highlighting Africa's unique rapid population growth compared to other regions. It discusses various countries' demographic transitions, noting that while Brazil, Japan, Germany, and the U.S. converge towards older populations, Nigeria remains distinctively young and diverges from this trend. The analysis emphasizes the implications of these demographic changes, particularly concerning economic development, labor force participation, and social entitlements.

1. Global Demographic Aging
& African Divergence
Gaetan Lion, May 4, 2022

2. Introduction
2
Analysis
This analysis focuses on population aging, population age categories in % (age pyramids), and overall
population growth. It looks at various geographic units (countries, continents, regions, World) from 1950 to
the Present (2019 & 2020). And, it looks at projections out to 2100.
Africa is an outlier to the overall global aging; its population growth (historical & projected) is far faster than
for other major regions.
Data
UN, Population Division (original data source).
We captured the data through two incredibly useful websites:
• populationpyramid.net
• Our World in Data.
Graphics.
We constructed the age pyramids using R ggplot2. This allowed us to combine them on single graph outputs.
We also used extensively Our World in Data graphic capabilities.

3. Basic Age Pyramid Types
YOUNG OLD
MATURE
3

4. Basic Age Pyramid Types Interpretation
YOUNG OLD
MATURE
very high fertility
short life
expectancy
longest life
expectancy
longer life
expectancy
very low fertility
Low fertility
4

5. Basic Age Pyramid Characteristics & Implications
Young Mature Old
Fertility Very high
much higher than
replacement rate ( > 2.1)
Low
At or below replacement rate (2.1)
Very low
Much below replacement rate
( < 2.1)
Life expectancy Short Longer Longest
Population growth Very fast Slow Negative, population is
declining
Economic growth Fast Slower Slowest
Living standards Very low (catch up mode) High High
Fiscal burden (old-age) Very low
Few old people to support
High
Many more old people to support
Very High
Even more old people to
support
Literacy At times low Near 100% Near 100%
5

6. Underlying Explanatory Model
This is a basic economic development explanatory
model. As women get more educated, they
participate in the labor force. And, fertility drops,
life expectancy increases, population growth
slows down, and population ages.
This model explains how a population pyramid
evolves from looking like a pyramid (young) to a
urn (old).
6

7. Looking at visual data documenting the
Explanatory Model
7

8. Strong relationship
between rising women’s
education level (X) and
declining fertility (Y)
8

9. Strong relationship
between declining
fertility and rising women
labor force participation
outside of Africa.
9

10. Very high fertility in much of Africa
Fertility
10
The fertility replacement rate is 2.1. Greater than 2.1 suggests population growing; less than 2.1 suggests
population declining. Of course, immigration does have a strong impact on such outcomes.

11. Very low women labor force participation in Northern Africa, Middle East, and India.
Women Labor Force Participation
11

12. Very high fertility in much of Africa, Middle East, and Central Asia.
Population Growth
12

13. Australia, Canada, New Zealand, US, and part of Europe did not report
this indicator. It should be red, reflecting high women literacy rate.
Women Literacy
13
Africa stands out with very low
women literacy rate.

14. 14
For the most part, the
explanatory model is in line
with the demographic data.
Countries with high women
literacy (+) have high
women’s labor force
participation (+), low fertility
rate (-), and low to negative
population growth (-).
The exception is a good part
of Africa where many
countries have a high
women’s labor force
participation and yet still
high fertility and fast
population growth.
1
2
3 4

15. Fertility (-)
Women labor force participation (+)
Population growth (-)
Women literacy rate (+)
15
1 2
3
4

16. Demographic aging Convergence focused on four
countries representative of large regions
1) Brazil, representative of South America
2) Japan, representative of Asia
3) United States, representative of North America
4) Germany, representative of Europe
We also selected Nigeria as representative of Africa. But, that is the
divergent country that does not converge towards demographic aging.
16

17. 17
Brazil
Brazil experiences a spectacular transition from a very young population (1950 – 1985) to a very mature one (2019). And,
it is forecasted to have a very old population by 2100. Its population has increased very rapidly until the present. But,
based on UN projections it is expected to peak around 2050, and decline ever after.

18. 18
Germany
Germany has always had a mature to old population. It has continued aging slowly from 1950 to 2019. Based on
UN forecast, its population is already expected to decline over the next couple of years and continue to do so until
the end of the forecast (2100). However, the population decline is forecasted to be very slow.

19. 19
Japan
Japan has experienced one of the most rapid population aging. It had a very young population in 1950. It already had a
pretty mature one by 1985, and old one by 2019, and is forecasted by the UN to have a very old one by 2100. Its
population has already started declining in 2011. And, unlike Germany its population decline is expected to be much
faster till the end of the century.

20. 20
United States
The US population aging is a lot slower than for the other three countries shown so far. This is due to a higher rate
of immigration that compensates for declining fertility and rising life expectancy. Thus, unlike the other mentioned
countries, its population is expected to continue rising (albeit a slowing rate) until 2100.

21. 21
1950. 3 out of the 4 countries have similar pretty young population
In 1950, both Brazil and Japan have very young and nearly identical age pyramids. The US pyramid still looks pretty
young. Only Germany already does show a mature pyramid. Already back in 1950.

22. 22
2019. Convergence towards a mature to old pyramid profile
Now, all the formerly young-pyramids from 1950 have morphed into mature to old-urns by 2019. Notice, that Japan
who had a very young looking population back in 1950, now has the oldest population in 2019. The ranking of the
countries on this dimension has changed.

23. 23
2100. By then, they all converge looking like old urns
Here the surprise is Brazil, who is rivaling Japan for having the oldest looking urn shape. They are both much older
than Germany. On a relative basis, the US urn shape does not look quite as old as the other three. And, as we
know the US population keeps on growing throughout the century. Meanwhile, the three other countries’
respective populations are projected to decline for several decades prior to 2100. .

24. 24
Convergence:
1950 - 2019
From pyramids to urns in 70
years.
Notice the exceptionally rapid
aging of Japan. It goes from
being a very young society
rivaling Brazil on this count, to
becoming the oldest society
among the four countries.
At the other extreme, notice
how slowly Germany’s
demographic has changed over
the same period.

25. 25
The convergence
continues till 2100
By 2100, they all look very much like
urns.
The surprise here is the expected
continuing aging of Brazil with a
demographic profile that rivals Japan,
and is much older than Germany… and
far older than the US.

26. 26
The full convergence
from 1950 to 2100
Notice how much younger the
demographic profile of Brazil and
Japan are in 1950. But, by 2100 both
of them have aged dramatically and
converged towards the other two
countries. Brazil and Japan now
actually lead in aging.
The pyramids & urns looked very
different in 1950. And, they look very
similar in 2100.

27. The Nigerian Divergence
27

28. 28
Nigeria
Nigeria’s population remains remarkably young over the past 70 years (1950 – 2019), unlike any of the other four
countries reviewed. It is only by 2100, that Nigeria’s population looks like it has aged a bit. Yet, at such date it is still
far younger than the other four countries. Truly, a divergent country.

29. 29
Comparing aging in Nigeria,
Brazil, and Japan.
In 1950, all three countries had very
young age pyramids.
In 2019, nearly 70 years later, Nigeria’s
age pyramid shape remains unchanged,
still looking very young. Meanwhile,
Brazil’s pyramid has aged a lot; and
Japan’s even more so.
By 2019, Japan’s pyramid already looks
like an urn, and depicts the oldest age
pyramid among major countries.
Nigeria is at the other end, and has one
of the youngest age pyramid among
major countries.

30. The population of
Nigeria rose from
37.9 million in 1950
to 206.1 million in
2020!
30

31. The population of Nigeria
is forecasted to grow
from 206.1 million in
2020 to 793.9 million by
2100!
Nigeria’s prospective
growth out to 2100 is far
faster than for the other
four countries: Brazil,
Japan, US, and Germany.
This divergence (faster
pop. growth) plays out
whether you look at
country level (Nigeria) or
large regions and
continental level (Africa).
Africa is the divergent
region.
31

32. Convergence & Divergence
at the Global Region Level
from 1950 to 2020
32
We will focus on four large regions that have each a huge population between 1.1 and 1.5 billion.
These regions are:
Africa
Europe & Northern America
China
India

33. 33
Africa’s rapid
exponential
population
growth is truly
amazing.

34. 34
Notice the far
slower population
growth, and far
more rapid
population aging.
This stacked graph
is pretty rich; as it is
capturing the
information of 70
yearly consecutive
pyramid charts
stuck together.
The only thing we
are missing in this
data aggregation is
the gender
differentiation.

35. 35
Very rapid growth for China
that is in between Africa and
Europe & Northern America.
China’s population kept on
rising beyond 1980 when its
one-child policy was
implemented. Yet, its fertility
rate did drop rapidly. But, other
Asian countries (Japan, South
Korea, etc.) experienced similar
decline in fertility without one-
child policies.
Notice the very large expansion
of the 25-64 year old age group.
This has facilitated China
becoming the manufacturing
labor force for the World over
the past 20 years.

36. 36
Another country
that experienced a
very rapid rise in
population from
1950 to 2020.
Also, notice the
bulging of the 25-
64 year old, very
similar to China.
This has facilitated
India becoming
the labor force of
off-shore IT and
services support
for the World.

37. 37
Africa has by far the
youngest population
associated with the fastest
growth.
India has 2nd fastest
pop. growth
Large labor force
for services
About 60%
of pop. < 25
Over 40% of
pop. < 25
Large labor
force for
manufacturing Fairly static
population
AFRICA INDIA
CHINA
Europe and Northern America

38. 38
Africa’s population
shows almost no
aging.
Around 60% of the
population is under 25
years old throughout
the entire period.

39. 39
China experienced fairly rapid
aging since 1975.
Notice the huge expansion in
the 25-64 year old since 1970.
This allowed China to become
the manufacturer for the
World.
The young have shrunk
dramatically as a % of total
population since 1970. As a
result, the huge and expanding
labor force (25-64) will start
contracting going forward.

40. 40
India’s
population is
aging slowly
compared to
China.
It still has a very
large youth
foundation that
should allow it to
replace the large
labor force over
the next
generation.

41. 41
On a relative basis, this
region is aging fairly
rapidly. See the
expansion of the 65+
year old.
The labor force (25-64)
has remained somewhat
static in % of pop. But, it
has to support a rising %
of senior citizen (65+).
The youth is declining
suggesting that the
population aging will
continue.
The above demographics
will exacerbate fiscal
pressures to support
social entitlements.

42. 42
Africa’s population is almost not
aging at all. Youth (< 25) account for
60% of population.
India’s youth population
proportion is shrinking
China’s population has aged
rapidly since 1970
Europe and North America
populations are continuing to age

43. Convergence & Divergence
at the Global Region Level
Out to 2100
43

44. 44
Europe and Northern America are on a different trajectory out to 2100
Europe’s population is projected to start declining
after 2020. Population will continue to age fairly
rapidly. This may be associated with slower
economic growth and intense fiscal pressure to
support rising social entitlements.
Northern America’s population will continue to age fairly
rapidly. But, the population is forecasted to continue rising
through 2100. Economic growth may be a bit faster and
fiscal pressures a bit milder relative to Europe.

45. 45
Very rapid population aging
Steady decline in youth
population after 2020
Contraction in labor force after
2050
Population starts declining after 2060

46. 46
Very rapid population aging
Contraction in labor force
after 2020
Shrinking youth population after 1990
Rapid population decline after 2030

47. 47
Population aging is much
slower than anywhere else,
resulting in Africa’s population
exceeding 4 billion by 2100!

48. 48
When focusing on % mix instead
of nominal population count, we
can more readily observe Africa’s
population aging.
Youth (<25) are projected to
decline from 60% of population
currently to about 35% by 2100.
Yet, on a comparative basis the
35% level is still very high.

49. 49
China’s population %
mix is expected to
stabilize by 2060. The
aging process will be
fully seasoned. And,
the shapes of
pyramids or urns, if
we constructed them,
would remain
unchanged from 2060
to 2100.

50. 50
In India, population
aging is continuing
through 2100.
Unlike China, it is
not expected to
stabilize.

51. 51
Europe and Northern America projected population mix in % out to 2100 look very similar. But, Europe’s population has
and will continue to age more than Northern America in every single decade. These slight variances in aging paths make
the difference between Europe’s population expected to shrink going forward, while Northern America’s is expected to
continue rising.

52. 52
Africa’s projected
population aging is much
slower than anywhere
else. And, it appears far
away from stabilizing.
China’s relative growth of 65+ is
faster than anywhere else. But,
aging is expected to stabilize by
2060.
India’s population aging looks
far away from reaching a
stabilizing point (unlike China
and Europe).
Europe’s population aging
is pronounced; but, is
projected to stabilize by
2060 (similar to China).

53. 53
Africa’s population mix by 2100 is very similar to Europe’s around 1980.
Europe’s population aging is projected to pretty much stabilize around 2060. If Africa’s demographic curves
follow the same path, it suggests Africa’s population mix and aging could stabilize around 2180.

54. 54
Africa’s historical and projected population growth rates are so much
higher than for the other regions.
By 2100, Africa’s population is projected to be much greater than all the other three regions combined!

55. 55
Africa’s population is leaping passed the other regions

56. 56
World prospective population growth. It is all about Africa
Between 1950 and 2020,
Africa’s population has grown
by a multiple of nearly 6 times!
The rest of the World has
grown by 2.5 times.
Out to 2100, Africa’s population
is expected to more than triple.
Meanwhile, the rest of the
World’s population is expected
to remain flat.

57. 57
Age Dependency Ratio: a demographic measure associated with fiscal stress
(social entitlements)
European Union
US
China
India
Age dependency ratios have steadily risen in Europe and US. This measure is starting to rise rapidly in China. Going
forward, this will be associated with increasing fiscal stress to fund social entitlements for the elderly.