Age Groups and the Measure of Population Aging

This paper proposes the use of optimal grouping methods for determining the various age groups within a population. The cuto� ages for these groups, such as the age from which an individual is considered to be an older person, are then endogenous variables that depend on the entire population age distribution at any given moment. This method is applied to the age distributions of some industrialized countries, for which cuto� ages as well as the main indicators of aging are calculated over the last 50 years.