GRAZIELLA CASELLI AND ALAN D. LOPEZ
In recent years, there has been a substantial literature on every facet of the daily lives of the elderly person. Psychological, social, economic, demographic, health, and even existential issues, have all been dealt with in great detail, seemingly keeping pace with the continual increase in the number of elderly persons and their lengthening life-span.
Prolonged old age has triggered a myriad of emotions, forged new values, and created different stereotypes. A new life stage is emerging, termed the fourth age, comprising people aged 80 years and over. Such an achievement, it would appear, is reserved for those who have succeeded in living a life without undue excess or, in other words, those who have made a number of choices and have managed to largely avoid risks judged as possibly compromising their survival. Longevity is the outcome of a series of positive choices, at the same time avoiding all those risk factors which could have precipitated death. Old age becomes a sort of virtue and takes on a role which, in sociology and psychology, restores dignity to the old person while, for the demographer or epidemiologist, it allows them to interpret longer survival as the direct outcome of life courses propitious for good health.
The more traditional outlook would now appear to have changed. Somewhat simplistically this only considered the links between the cause and effect of longer survival, and an increased elderly population, generally presenting longevity along with its ramifications for social and economic well-being, as the unexpected result of progress in the medical field, allowing ever-growing numbers of individuals to reach progressively higher ages.
Longevity and old age are two sides of the one coin and, moreover, represent a major issue for modern society, whose contours and mechanisms of interaction are, despite the wealth of existing literature on the elderly, largely elusive. This is also true for demography. Thus, while the importance of the effects of mortality decline on the increase of the elderly population has been frequently pointed out, there are few quantitative assessments of these same effects or how they have evolved over the long term, or indeed how they interact with the two other determinants of demographic change, namely natality and migration.