Editing Dependency ratio (section)

==Formula==
In published international statistics, the dependent part usually includes those under the age of 15 and over the age of 64. The productive part makes up the population in between, ages 15 – 64. It is normally expressed as a percentage:
:<math>\mathrm{(Total)\ Dependency\ ratio} = \frac{(\mathrm{number\ of\ people\ aged\ 0\ to\ 14}) + (\mathrm{number\ of\ people\ aged\ 65\ and\ over)}}{\mathrm{number\ of\ people\ aged\ 15\ to\ 64}} \times 100 </math>

As the ratio increases there may be an increased burden on the productive part of the population to maintain the [[child|upbringing]] and [[pension]]s of the economically dependent. This results in direct impacts on financial expenditures on things like [[social security]], as well as many indirect consequences.

The (total) dependency ratio can be decomposed into the child dependency ratio and the aged dependency ratio:<ref>[http://www.apheo.ca/index.php?pid=63 Association of Public Health Epidemiologists in Ontario] {{webarchive|url=https://web.archive.org/web/20110706164640/http://www.apheo.ca/index.php?pid=63 |date=2011-07-06 }}</ref>

:<math>\mathrm{Child\ dependency\ ratio} = \frac{\mathrm{number\ of\ people\ aged\ 0\ to\ 14}}{\mathrm{number\ of\ people\ aged\ 15\ to\ 64}}  \times 100 </math>

:<math>\mathrm{Aged\ dependency\ ratio} = \frac{\mathrm{number\ of\ people\ aged\ 65\ and\ over}}{\mathrm{number\ of\ people\ aged\ 15\ to\ 64}} \times 100  </math><ref name=Migration2008 />