Chapter Four: Transitional Age Structures

Countries with a transitional age structure are so termed because they are in the middle of the demographic transition, with mortality rates usually not much higher than those of fully industrialized countries and fertility rates on a similar decline. They have been passing through the demographic transition long enough for the proportion of children and adolescents to stabilize with that of young working-age adults. Transitional age structure countries are presented with a clear opportunity to experience the greatest economic benefits of the demographic transition. To do so, however, is not automatic: Governments must make wise investments in health and education, and the economy must be sufficiently developed to offer a sufficient number of jobs to new entrants into the labor force.

Over the thirty-year period at the end of the twentieth century, the risk of civil conflict among countries with a transitional structure has held fairly steady. On average, countries in this category have been slightly more likely to experience conflict than those in the mature category and slightly less likely than those with a youthful structure. In the 1990s, the four new outbreaks of conflict in these countries (Bosnia and Herzegovina, Georgia, Moldova and Serbia and Montenegro) were all in a region affected by the demise of the Soviet Union.

Figure 4.1
Transitional Age Structure Profiles

Youth (ages 0-29) approximately 45-60 percent of total population
Mid-Adults (ages 30-59) approximately 27-40 percent of total population
Seniors (ages 60+) approximately 8-15 percent of total population
Demographic character Although older age groups are still very small proportions of the population, there are only gradual declines in proportion among those age groups under 40.
Population doubling time 50-125 years
Country count 40
Regional prevalence Latin America, Caribbean, South Asia, China, parts of Middle East
Civil conflict risk 9 percent likely to experience civil conflict, 1970-99
Economic performance 3.6 percent median average annual GDP growth rate, 1970-99
Governance 74 percent likely to have fully democratic governance, 1970-99

Countries with a transitional age structure have a high average GDP growth rate, at 3.6 percent, which may be tied to those countries' demographic development. As death rates and birthrates decline, every country experiences a decades-long "demographic bonus"; when working-age adults make up the largest share of its population, and there are relatively small groups of dependent children and older adults compared to previous generations. The lower dependency ratios during this period can lead to higher savings, greater per capita government spending on education and health, and increased wages. Such benefits of the demographic bonus contribute to boost countries' economies, as was the case of the "Asian Tigers"; in the 1970s and 1980s.¹

The opportunity for countries to take advantage of this demographic window is relatively short, usually less than 40 years, until the median age of the population increases and the higher proportion of older adults begins raising dependency ratios. Countries in the later stages of a transitional age structure, such as Chile, will see their window of opportunity close by 2015. Countries in the early stages of a transitional age structure or with a youthful age structure are just at the beginning of the demographic bonus period, and it has yet to occur in countries with very young age structures.² In order to take advantage of the demographic bonus and the economic benefits it offers, governments must implement policies focused on young people, to ensure that they have adequate education and employment and that the transition toward smaller families continues.

Figure 4.2
Risk of Civil Conflict by Age Structure Type

Nearly three-quarters of countries with a transitional structure were fully democratic, on average, between 1970 and 1999. Their probability of democratic governance was more than three times greater than that of countries with a youthful age structure, the previous category along the demographic transition. By the 1990s, many of the countries of Western Europe and other highly developed regions had mature age structures, and were replaced in the transitional structure category by countries in Eastern Europe and a few each from East Asia and South America. Complete governance data were not available for many of the Eastern European states, which may have made the average democratic score for countries in this group artificially higher.

Figure 4.3
Age Structure Type and GDP Growth³

Figure 4.4
Governance and Age Structure Type

Countries in Profile: Mexico

Health Reforms Address Double Burden of Disease

Perhaps the most unique feature of Mexico's demographic and health situation is the stark difference in social and economic status between subpopulations. In many respects, Mexico resembles a developed country completing the demographic transition, with a life expectancy of 75 years, and crossing into the transitional age structure category. At the same time, marginalized populations within indigenous regions of the country more closely resemble the demographic characteristics found in the very young age structure that lag far behind in health, economic and social status. Interestingly, within the Mexican state of Chiapas, demographic statistics more resemble a conflict-marked country with a very young or youthful age structure. In 1994, after the North American Free Trade Agreement (NAFTA) was signed, Zapatista rebels began the "Ya Basta"; uprising in Chiapas. The conflict, focused on issues of land reform and globalization, faced rapid reprisals from the Mexican army, and the Zapatistas and the government currently remain in a tense standoff.

This marked difference between subpopulations in Mexico has left the country facing a double burden of disease. As a country moves through the demographic transition, it also goes through an epidemiologic transition whereby the diseases of poverty persist even as diseases of affluence become more prevalent. Eventually, as overall health continues to improve, the country will leave behind most of the diseases of poverty. The health system of Mexico, in the middle of this transition, faces the double burden of disease. While still suffering from illnesses associated with poverty, including malnutrition, communicable diseases and reproductive health problems, other diseases typically associated with industrialized societies have emerged, creating a higher strain on health resources. These include conditions such as cardiovascular disease, obesity and cancers.⁴ Mexico's development of a transitional age structure occurred very recently and very rapidly. The country had a very young age structure as recently as 1990. In 15 years' time, the age structure progressed through two categories, reaching the transitional type in 2005. It is projected to remain in, but be nearing completion of, the transitional category in 2025.

Figure 4.5
Mexico's Age Structures, 1975 and 2005

Mexico's age structure profile changed dramatically in a short period of time. In 1975, with nearly 73 percent of the population younger than 30, Mexico's age structure held a classic pyramid shape, with significantly decreasing proportional size among each successive older age group. By 2005, the share of the population under 30 had declined to 59 percent, and the younger half of the profile was much more balanced.