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

Subtypes

At sustained high levels, unique demographic forces such as pandemic diseases and international migration can have a major impact on population age structures. In countries with a mature age structure and high inward-migration rates, such as the United States, age structures are generally younger than they would otherwise be, because immigrants tend to have higher fertility rates than the native-born population. Though these countries are far along the demographic transition and their mortality and fertility rates have already declined, the impact of immigration keeps most of them in the earlier stages of the mature category.

Labor migration to the Arab Gulf states makes their age structures, which are in the middle of the demographic transition, more mature than expected. Although mortality rates have declined in these countries, fertility rates among the native-born population remain above replacement level. Since most immigrants in this region are of working age and policies discourage or prohibit their remaining in the country after retirement, the countries' age structures contain a bulge in the middle of the population, with an extremely small proportion of older adults.

In countries in southern Africa with the highest rates of HIV infection, two to three percent of working-age adults die each year, more than 10 times the normal rate. Still, high fertility rates mean that AIDS mortality is not having significant impact on population growth, while straining educational opportunities for children left behind.

Age Structure And Conflict

Between 1970 and 1999, 80 percent of all outbreaks of civil conflict that resulted in at least 25 deaths and in which the government was an actor occurred in countries in which 60 percent or more of the population was under age 30. During the 1990s, countries with a very young age structure were three times more likely to experience outbreaks of civil conflict than countries with a mature structure.

Age Structure And Governance

Between 1970 and 1999, countries with progressively more balanced and older population age structures were also more likely to have a fully democratic government. Nearly 90 percent of countries with very young structures had an autocratic or only weakly democratic government at the end of the 20th century, while more than 80 percent of countries with mature structures were fully democratic.

Age Structure And Economic Development

Countries with a transitional age structure can experience significant benefits from demographic change, if their governments take advantage of the opportunity it presents. Between 1970 and 1999, these countries experienced an average annual economic growth rate of 3.6 percent. This could be due to what has been called the demographic bonus, a favorable opportunity for economic and social development that arises when lower fertility rates lead to reduced dependency ratios, increased wages and savings, and greater government and household investment in education and health.

Policies And Programs Can Shift Age Structure

Age structures are dynamic and can be influenced through policies that affect the demographic forces—births, deaths and migration—that shape them.

In countries that have not yet advanced along the demographic transition, especially those with very young and youthful populations, research and experience demonstrate that lower death and birth rates can be spurred by a range of social interventions. Initiatives that have worked successfully in many countries include improving access to family planning and reproductive health care, education for girls and economic opportunities for women. Governments should form strong international partnerships with comprehensive policies and adequate funding to support programs that help foster more balanced age structures.

Countries with a transitional age structure have already benefited from policies and programs that encourage demographic development, but their continued progress is not guaranteed unless governments make deliberate efforts to maintain this momentum. Access to a broad range of sexual and reproductive health services, such as contraceptives, should be expanded to make them universally available and affordable. Programs to improve educational attainment and economic opportunities for women should reach full scale.

With their low fertility and mortality rates and more balanced age structures, countries with a mature age structure have generally been the most stable, democratic and wealthy. Any economic or other risks related to population aging should be addressed through policies that work to balance women's professional and family responsibilities and increase men's involvement in childrearing. These and other innovative approaches can also help reduce the likelihood that population aging-an inevitable byproduct of the longer lives and smaller families that define demographic transition-will cause significant social and economic disruption.