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Giambattista Salinari and Gustavo De Santis

Figure 7. Relationship between stature and the onset of ageing.
Note: The data on the onset of ageing were given in Figure 3 and refer to female cohorts. The data on statures come from Hatton and Bray (2010)
and refer to male conscripts (by cohort).

The onset of ageing: A change in the variability of the observed force of mortality may
produce the illusion of a delayed onset of ageing in older cohorts. But this happens only
when older cohorts suffer from a higher variability in the δ x series. In our case, the oppo-
site is true both theoretically (because of the small number of deaths among younger adults)
and empirically (Salinari and De Santis, 2015).
Mortality crises too, for example wars and epidemics, could in principle, bias the results.
Most of the cohorts considered in our analysis were observed only after WWI and the
Spanish pandemics, the two major mortality crises of the twentieth century. Moreover, two
of the countries that we analyzed, Sweden and Switzerland, did not take part in any wars
and in all cases we focused on women who were much less exposed than men to the risks
of war.

International Journal of Population Studies | 2015, Volume 1, Issue 1 53