1. A world without aging Discussion
Natalia S. Gavrilova, Ph.D.
Center on Aging
NORC and The University of Chicago
Chicago, USA

2. Conceptual framework
Mortality
Negligible senescence
Population Size and Age Structure
Economic and Social Change
Environmental Change
Rising Fecundity
Fertility
In 1959, Ansley Coale studies the population impact of immortality. At the time, fertility was so high that deaths were a drop in the population bucket.
Coale’s study assumed no change in fecundity.

3. The case of immortal population
Suppose that parents produce less than two children on average, so that each next generation is smaller:
Generation (n+1)
Generation n
Then even if everybody is immortal, the final size of the population will not be infinite, but just
larger than the initial population.
= r < 1
1/(1 - r) 3

4. The case of immortal population
For example one-child practice (r = 0.5) will only double the total immortal population:
Proof:
Infinite geometric series converge if the absolute value of the common ratio ( r ) is less than one:
1 + r + r2 + r3 + … + rn + … = 1/(1-r)
1/(1 - r) = 1/0.5 = 2
Source: Gavrilov, Gavrilova, Rejuvenation Research, 2010 4

5. Population will grow But fertility still matters a lot

6. Population projection without life extension interventions
Start of population decline after 2025 6

7. Population projection with negligible senescence scenario
Source: Gavrilov, Gavrilova, Rejuvenation Research, 2010 7

8. This Paper Goes Further
Several scenarios with different fertility levels (assumes long-term fecundity)
Several scenarios with different cost of life extension technologies
Economic issues
Health expenditure issues

9. Globalization
The model assumes uniform behavior for all 186 countries. Looks unrealistic (and authors admit it). It may be interesting to consider developed and developing countries separately.
Too heavy assumption about uniform acceptance of life extending technologies.

10. Mortality
In the case of negligible senescence when crude death rate is close to zero we may expect that individuals will live 1000 or more years on average.
In this case setting retirement age based on age per se may be financially prohibitive. We may expect retirement benefits based on health status assessment.
If morbidity from mental diseases declines less rapidly compared to other diseases we may expect accumulation of mentally disabled persons over time.

11. Fertility
If individuals live 1000 years or more and retain their fecundity will they limit the total number of offspring by two children only?
What is fertility schedule among the species with negligible senescence?

12. Adding medium fertility scenario
Aging population, peaks

13. Will it be like in China? Introduced one-child policy in 1978-80

14. Changes in population pyramid 100 years later
Sweden, 2005
Source: Gavrilov, Gavrilova, Rejuvenation Research, 2010