gustavo de santis - ageing senescence and longevity

DiSIADIPARTIMENTO DI STATISTICA,INFORMATICA, APPLICAZIONI "GIUSEPPE PARENTI"

Ageing, senescenceand longevity:

are there limits?

Gustavo De Santis

Migration Policy Centre, Forum on Migration, Citizenship and Demography:

Conference on Demography

European University Institute (Fiesole, Italy), 4-5 February 2016


Yasutaro Koide (13 Mar 1903 - 19 Jan 2016)

Source: «La Repubblica», 19/1/2016 2


Other world records of longevity

3

• The male longevity record now belongs to another Japanese: Masamitsu Yoshida (aged 111). As for females, the world record of longevity belongs to an American (Brooklyn, New York), Susannah Mushatt, aged 116 (Source: La Repubblica, 19/1/2016)

• Other famous cases, of people who died recently, are those of the French Jeanne Calment (who died in 1997, at the age of 122years and five months). Then, the American Sarah Knauss reached 119 years, while the Canadian Marie-Louise Meilleur and Japanese Misao Okawa reached 117. Eight more cases have been documented to have reached 116 years between 1990 to 2014, and twenty-five have reached 115 years (Source: Jacques Vallin, in N-IUSSP, www.niussp.org).


Highest age at death, by sex and year(Sweden 1861-1999)

Source: Wilmoth et al (2000) “Increase of maximum life-span in Sweden”, 1861-1999, Science n° 289, p. 2366-68 4


Maximum longevity vs maximum life expectancy

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• Maximum longevity? Probably just above 122 years (Source: J. Vallin, in N-IUSSP)

• Is this maximum longevity increasing? No solid evidence, as yet. (Bad data and few observations for the past, so that the time series is actually much shorter that it seems.)

• Does this imply that life expectancy too will reach 120 years? Highly unlikely, because life expectancy is an average, not a maximum – and heterogeneity (frailty) matters a lot. Most probably, then, e0 will stop increasing somewhere between 90 and 100 years. And these levels will not be reached tomorrow.


Highest life expectancy (World, 1840-2000):A straight line?

Source: Oeppen and Vaupel (2002) “Broken limits to life expectancy”, Science, 296 (10), p. 1029-1031 6


Highest life expectancy (World, 1750-2000):probably slowing down

Source: Vallin and Meslé (2009) “The segmented trend line of highest life expectancies”, P&DR, 35(1), p. 159-187 7


Life expectancy at birth by world region, 1950-2050

Source: UN (2015) World Population Ageing 8


Probability of survival to age 80 by sex and region, birth cohorts of 1950-1955 and 2000-2005



The over 60 population is the fastest growing age group worldwide



Population over 60: rampant (not only in Europe)



Ageing is a worldwide phenomenon


Germany

Brazil


Sustainability of pension systems endangered


• “In some countries, large majorities of older people are covered by existing pay-as-you go or unfunded pension programmes, but declining old-age support ratios imply that such programmes may struggle to maintain adequate income support into the future.

• In response, some countries are pursuing pension system reforms, such as increasing the statutory ages at retirement and encouraging private savings.”


Cost of health care systems may skyrocket


• “Health care systems must adapt to meet the needs of growing numbers of older persons.

• In countries [with good health systems] public policies are needed to mitigate the upward pressure on national health care budgets exerted by the rising costs of health care services, and the longer lifespans and increasing numbers of older persons.”


In the eyes of the beholder?

Source: Own elaborations on UN data

* P&DR15

Share aged 65+

Share with a residual life

expectancy of 15 years or less (i.e.,

moving “beta”)

[what Sanderson and Sherbov

(2013, 2015)* have recently

labelled “prospective old age”]


Other approaches to measuring ageing (Who is old?)


• Last five years of life (because health cost soar in the final phase of one’s life): called “Health care cost old age” (Sanderson and Sherbov, P&DR, 2015). (A/N Not qualitatively different from the previous indicator, remaining life span of 15 years or less)

• “Characteristics” approach: based on health, or performance, memory, and the like (A/N only for samples, not always representative, or comparable)


Immediate recall score, by age and region

Source: Skirbekk V., Loichinger E., Weber D. (2012) Variation in cognitive functioning as a refined approach to comparing aging

across countries, Proceedings of the National Academy of Sciences of the United States of America , 109 (3): 770-774. 17

80 85 90


Survival is (by large) the main driver of ageing,in the long run (not fertility or migration)

Source: Own elaborations on UN (2015) data 18

Europe, early 1950s

Stationary population

Actual population


Actual and stationary population: comparing age structures in 1952 (Europe)


1952

DiSIADIPARTIMENTO DI STATISTICA,INFORMATICA, APPLICAZIONI "GIUSEPPE PARENTI"Survival and ageing (Europe, 150

years of estimates and projections)


1952

2012

2047

2097


The difference between Px and Lx is limited and decreasing

Sum of absolute % differences, over 21 5-year age classes


DiSIADIPARTIMENTO DI STATISTICA,INFORMATICA, APPLICAZIONI "GIUSEPPE PARENTI"Ageing is no longer an issue if

threshold ages are properly adjusted



Conclusions: limits?

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• IF we can properly adjust threshold ages, the part of ageing driven by survival (the most important, in the longrun) is no longer an issue. (Big IF! And there will still be ageing problems linked to fertility)

• If this adjustment is not possible, or not fully (first limit), then greater need for transfers between generations, which is arguably harder to push beyond certain levels (Laffer curve, and similar objections) (second limit).

• I don’t know what the physical (natural) limits to ageing and survival are. I know that we must overcome our own (social) limits, i.e., we must be capable of adapting to the ageing society that we are creating. Or be prepared to pay the consequences.


Ageing, senescenceand longevity:

are there limits?

Gustavo De Santis

Migration Policy Centre, Forum on Migration, Citizenship and Demography:

Conference on Demography

European University Institute (Fiesole, Italy), 4-5 February 2016

gustavo de santis - ageing senescence and longevity

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