Age Structure

A characteristic of a population which reflects its historical trends in birth and death rates. Until the 20th century, the human age structure had remained relatively constant and had a pyramidal appearance with a relatively large number of children at the base and, due to a higher average mortality in the 30–50+ group/1000, a narrow apex of persons who made it to old age. With the improving health and decline in both infant mortality and birth rate, the age structure is undergoing a transition, to an increasingly columnar form, especially as developing nations achieve a balanced rate of reproduction.

单词	age structure
释义	age structure age structure [′āj ‚strək·chər] (anthropology) Categorization of the population of communities or countries by age groups, allowing demographers to make projections of the growth or decline of the particular population. Age Structure Age Structure A characteristic of a population which reflects its historical trends in birth and death rates. Until the 20th century, the human age structure had remained relatively constant and had a pyramidal appearance with a relatively large number of children at the base and, due to a higher average mortality in the 30–50+ group/1000, a narrow apex of persons who made it to old age. With the improving health and decline in both infant mortality and birth rate, the age structure is undergoing a transition, to an increasingly columnar form, especially as developing nations achieve a balanced rate of reproduction.
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