This is a study using historical data and forecasts of life expectancy for several countries. The data and forecasts come from the UN - Population Division. While the historical data is most interesting, the forecasts are highly optimistic as they project a linear trend way into the future. Meanwhile, those forecasts should have followed a much more realistic logarithmic curve reflecting slower increase in life expectancy as the life expectancy rises.

1. Life Expectancy Trends
Will we soon live to a 100?
The danger of linear extrapolation
Gaetan Lion, February 1, 2022

2. Life Expectancy History
I am focusing on several countries with long life expectancy
plus the US and China.
2

3. The Countries
Anglo Saxon European Asia
Australia Spain China
Canada Sweden Japan
New Zealand Switzerland Korea*
USA
* South Korea
3

4. Source: United Nations – Population Division
Since 1980, life expectancy has
grown a lot slower in the US. And,
over the most recent decade it
has remained flat at around 79
years.
Meanwhile, it has kept on rising
fairly rapidly reaching between 82
to 84 years for the other Anglo
Saxon countries.
4
The US lags big time

5. Source: United Nations – Population Division
In 1950, Spain’s life expectancy was
much shorter than Sweden and
Switzerland. But, it caught up with
the others by 1980. And, these three
European countries respective life
expectancy kept on rising fairly rapidly
to the present reaching around 83
years old currently.
5
Spain catches up

6. Source: United Nations – Population Division
Back in 1950, both Korea
(meaning South Korea) and China
had respectively far shorter life
expectancy.
Korea has nearly caught up with
Japan who has the longest life
expectancy among major
countries. China’s life expectancy
has also risen dramatically, but
not quite as much as Korea.
6
South Korea catches up to
Japan

7. Source: United Nations – Population
Division
Several of the Anglo Saxon, European,
and Asian countries respective life
expectancy has converged upward
towards 82 to 84 years old. This is
despite these countries being
geographically and genetically very
distant. And, also starting from
drastically different life expectancy
back in 1950.
7
Convergence

8. Focusing on the converging
countries, the upward visual
convergence towards a life
expectancy in the 82 to 84 year old
range is spectacular. This is
especially the case when you note
the geographical and genetic
distance of the respective countries
and the drastically different starting
points back in 1950.
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9. Healthy Life Expectancy History
Healthy life expectancy equals life expectancy minus years living with disability. This
typically truncates life expectancy by 8 to 11 years depending on the country.
9

10. Source: IHME, Global Burden of Disease
Again, notice how the US is not
faring well on a relative basis. Its
upward slope of the rising healthy
life expectancy trend line is far
flatter than for the other countries.
And, the mentioned US slope has
remained flat since 2010.
10
The US lags big time

11. Source: IHME, Global Burden of Disease
Spain achievement on this
count is not well known.
Few would expect that
Spaniards would
outperform the Swiss and
Swedes on this one
measure.
11
Spain surprises

12. Source: IHME, Global Burden of Disease
There is a remaining
reasonably strong
differentiation between the
three Asian countries.
China is still way behind the
other two countries.
12

13. Source: IHME, Global Burden of Disease
The convergence between
these countries is visually not
quite as noticeable than when
focusing on life expectancy.
This is in good part due to the
different sensitivities (or
shorter yearly intervals)
disclosed on the Y-axis of the
graphs.
13

14. Comparison Summary
14

15. Source: United Nations _ population Division.
IHME, Global Burden of Disease
When you look at actual numbers, you observe that the rate
of convergence between countries is very similar for both
measures (life expectancy and healthy life expectancy).
Notice how in both measures, the US and China trail far
behind the other countries.
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16. Life Expectancy Forecast out to 2099
16

17. Source: United Nations – Population Division
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Highly optimistic, read later why.

18. Source: United Nations – Population Division
18
Highly optimistic, read later why.

19. Source: United Nations – Population Division
19
Highly optimistic, read later why.

20. Source: United Nations – Population Division
20
Highly optimistic, read later why.

21. Why the Life Expectancy Forecasts to 2099 are
optimistic
21

22. The Danger of Linear Extrapolation: The data
Note how the projections assume a constant increase of around 1 to
1.1 year per decade increase in life expectancy.
Source: United Nations – Population Division
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23. The Danger of Linear Extrapolation: The Narrative
Adding one year to life expectancy gets increasingly difficult as you move upward from
80 to 85 and 90 years old.
“Attaining a life expectancy of 90 requires the equivalent of cures for cancer, all
cardiovascular diseases, diabetes, infectious diseases, and accidental deaths. Getting to
95 requires the elimination of all known causes of death short of aging”
Dr. S. Jay Olshansky
Professor of epidemiology and biostatistics at the University of Illinois School of Public Health and Board
Member of the American Federation for Aging Research.
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24. Will we ever reach a life expectancy of a 100? Or even 90?
The Law of Averages raises serious doubt
“ … The law of averages requires that for 100 to be the new life expectancy, a
significant proportion of the population routinely must survive beyond the current
maximum lifespan limit of 122-an age known to have been reached by just one
person. This alone is sufficient to cast doubt on claims that 100 is the new normal.”
Dr. S. Jay Olshansky
Using Olshansky’s logic suggests that reaching a life expectancy of 90 would be challenging.
For each person dying at 70, you need 1 making it to 110.
For each person dying at 50, you need 2 making it to 110.
For each child-birth casualty, you would need 4.5 individuals making it to 110.
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25. UN projections are highly optimistic outlining the danger of
linear extrapolation into the distant future
Source: United Nations – Population Division
The converging countries’ life expectancies
cross 90 by mid 2070s, and keep on
trucking upward (1.1 year per decade)
following a linear trend till 2099.
Instead, it is more likely that the trend lines
will follow a logarithmic curve with each
decade corresponding to an ever
decreasing increase in life expectancy.
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26. Health trends are not supportive of ever
rising life expectancy
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27. Prevalence of diabetes type 2 is increasing rapidly worldwide
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28. Diabetes prevalence has risen very rapidly in the US
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29. Diabetes prevalence has more
than doubled in China within
less than two decades.
The trend is flatter in Japan
and Korea.
China
29

30. Obesity is rising worldwide
North America
& Europe
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31. Obesity is increasingly prevalent among both adults and children worldwide
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32. BMI is rising rapidly for both the US and the World
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33. The prevalence (%) for the
tranches in yellow, orange,
and red are growing rapidly
over time for both men and
women worldwide.
These tranches denote the
% of the population that is
overweight or obese.
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34. In high income countries, the level of fitness has declined during the 21st century
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35. Physical fitness is inadequate for close to a third of the population worldwide
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