Why Population Age Structure Matters To A Safer, More Equitable World

Countries with a favorable age structure-those with a large proportion of working-age adults and relatively few dependents-are generally more peaceful and democratic, allowing governments to better meet the needs of their people. An adverse age structure is more challenging to governments, particularly when national resources are insufficient to improve economic and social welfare. Countries that progress along the demographic transition-changing from high death rates and birthrates to smaller families and longer lives-generally demonstrate more favorable age structures.

Age Structure Types

Population age structures yield insights into many of the political, economic and security challenges that countries face, now and in the future. For example, when a large proportion of a country's population is passing through one of life's dependent stages, such as childhood or old age, society's resources are likely to be stretched and put under greater stress.

PAI has classified current and past national populations into one of four major age structure categories: very young, youthful, transitional and mature. These four profiles represent progressive steps along the path of the demographic transition-changing from high death and birthrates, large families and short life expectancy to lower death rates and birthrates, smaller families and longer life expectancy. In the future, if fertility rates continue to fall in countries with a mature structure, a fifth type may emerge before 2025: aged countries. 

Very Young

In countries with a very young age structure, two-thirds or more of the population is typically comprised of young people under age 30, and only three to six percent of the population is above age 60. In 2005, there were 62 countries of this type, including nearly all of sub-Saharan Africa.

Youthful

Countries with a youthful age structure are beginning to experience progress along the demographic transition. Growth among their youngest age groups (from birth through 29 years) is declining. In 2005, 27 countries fit this category, including almost all in Central and South Asia, North Africa, and parts of the Middle East.

Transitional

Although older age groups still represent a very small share of the population in countries with a transitional structure, declining fertility rates result in a more equitable distribution among age groups younger than 40. In 2005, this category included 40 developing countries from various regions.

Mature

In countries with a mature age structure, the largest age group consists of working-age adults from 30 through 59 years old, comprising 40 to 55 percent of the population. In 2005, this category included 47 countries across Europe, the former Soviet republics, and East Asia.