Medianalder

Medianalder, or median age, is the age that divides a population into two equal groups when all individuals are ordered by age. It is a standard demographic indicator used to summarize the age structure. Unlike the mean age, the median is less influenced by very young or very old individuals and thus provides a stable measure of central tendency for ages.

Calculation and interpretation: In a population of n individuals, the median age is the middle value if n is odd; if n is even, it is the average of the two central ages. In aggregated data, medianalder is derived from the age distribution or population counts by age. It reflects long-term effects of fertility, mortality, and migration on the age structure of a population.

Uses and implications: Governments and researchers use medianalder to assess workforce size, pension and health-care needs, and broader economic dynamics. A rising median age signals population aging and can influence policy on retirement ages, education planning, and labor markets. It complements measures such as age structure, life expectancy, and dependency ratios.

Limitations: The median provides limited information about the tails of the distribution; two populations can have the same median yet very different age pyramids. Data quality, survey method, and the choice of date or year can affect comparability across regions and over time.