of the portion of a population
which is composed of dependents
(people who are too young or too old to work). The dependency ratio
is equal to the number
of individuals aged below 15 or above 64 divided by the number of individuals aged 15 to 64, expressed as a percentage. A rising dependency ratio is a concern
in many countries that are facing an aging population, since it becomes difficult for pension
and social security systems
for a significantly older, non-working population.