New concept of age(ing): Prospective age
Authors: Devedzic Mirjana , Stojilkovic Jelena 
Published: February 2013

While the last century was the century of world population growth, according
to demographers, the XXI century will be century of population aging.
Statistics undoubtedly show that number of elderly will continue it?s growth
in the future. If old age is seen as period of life with reduced physical and
mental capabilities and increased disability, and demographic aging as
increase of dependent population, trends are quite disturbing, at least in
certain societal segments. In developed countries, this population category
is no longer treated as passive or as a "burden of society" and efforts are
made for better social inclusion of older people. In contrast to growing
interest in this phenomenon, the concepts that define the aging of the
population remained stagnant. The aim of this paper is to introduce into
domestic literature the term "prospective age" as a dynamic category which is
more affected with socio-historical conditions, not only with biological as
traditional definition of aging suggested. Papers written by Sanderson and
Scherbov offer new methodological options for study of population aging,
because it takes into account the biometric rather than chronological
approach. Calculation of prospective years is a simple operation that
requires pair of the same number of remained life expectancy from life tables
for two different periods (the year of concern is index, and the one we are
comparing with is standard year), so that phrase "40s is the new 30s" or "70s
the new 60s" gets scientific foundation. Average remaining years of life
represent a realistic indicator suggesting increased capacity, activity and
vitality of individuals, which is due to accepted demographic parameters
still considered old. ?Prospective threshold? is defined as the age when life
expectancy falls below 15 years (it is subjective choice made by Sanderson
and Scherbov, which is also used in this paper) and during the elaboration of
these ideas three demographic indicators was constructed, redefined more
precisely, based on prospective age: (prospective) share of the elderly,
(prospective) median age and (prospective) old age dependency ratio. With
respect to the remaining years of life in the calculation of demographic
aging, world?s population will be in rejuvenation process by 2035, longer and
more intense than defined by proportion of the elderly. Prospective approach
found that longer life expectancy in developing countries is not only a
result of the decrease in infant and child mortality, but also the decrease
of the old population mortality. Data used in this paper are from period life
tables and censuses, for period 1953-2010. Prospective age threshold in
Serbia was always higher than retrospective age (60,17 in 1953 .and 63,15 in
2010. for total population) , or the proportion of people with a life
expectancy less than 15 years has consistently been higher than the share of
people older than 65 years (17.86% vs. 16.92% in 2010). According to
prospective criteria, differences between men and women almost do not
existent, so that it calls into question the widely accepted feminization of
the elderly. The same conclusion stands when we discuss (prospective) median
age, population is older using prospective (47,15 years) than traditional
(41.41) indicator in 2010, also, compared with rest of the region or with
more developed countries, prospective median age is higher in Serbia. Also,
prospective old-age dependency ratio is higher than conventional one during
analyzed period. Prospective concept and amendments are necessary in public
policy, especially pension and health care system, because in combination
with traditional approaches can create more justified distribution for older
and younger generations.