10-2 Population Age Structure

What Are Age Structure Diagrams? Sorting People by Age Groups

Even if the replacement-level fertility rate of 2.1 were magically achieved globally tomorrow, the world’s population would keep growing for at least another 50 years (assuming no large increase in death rates). The reason is a population’s age structure: the distribution of males and females in each age group.

Demographers construct a population age structure diagram by plotting the percentages or numbers of males and females in the total population in each of three age categories: prereproductive (ages 0–14), reproductive (ages 15–44), and postreproductive (ages 45 and up).

How Does Age Structure Affect Population Growth? Teenagers Are the Population Wave of the Future

Any country with many people below age 15 has a powerful built-in momentum to increase its population size unless death rates rise sharply. The number of births will rise even if women have only one or two children, because a large number of girls will soon be moving into their reproductive years.

How Do the Canadian and U.S. Populations Compare? Similar but Not the Same

The two countries are practically identical in terms of degree of urbanization, access to birth control, availability of safe drinking water, and use of energy. Americans are marginally younger and more fertile. Canadians live slightly longer and have a lower infant mortality rate.

A key difference between the two countries is population size. The U.S. population is 10 times larger than the Canadian population. However, although it is possible to live in very remote circumstances in Canada, most Canadians live at densities comparable to those found in the United States.

How Can Age Structure Diagrams Be Used to Make Population and Economic Projections? Looking into a Crystal Ball

Baby boomers now make up nearly half of all adult North Americans. As a result, they dominate the population’s demand for goods and services. They also play an increasingly important role in deciding who gets elected and what laws are passed.

According to some analysts, the retirement of baby boomers is likely to create a shortage of workers in North America unless immigrant workers replace some of these retirees. Much of the economic burden of helping support a large number of retired baby boomers will fall on the baby-bust generation. It consists of people born between 1965 and 1976.

What Are Some Effects of Population Decline from Reduced Fertility? Sliding Down a Hill Too Fast Can Hurt

As the age structure of the world’s population changes and the percentage of people age 60 or older increases, more countries will begin experiencing population declines. If population decline is gradual, its harmful effects usually can be managed.

But rapid population decline, like rapid population growth, can lead to serious economic and social problems. A country undergoing rapid population decline because of a “baby bust” or “birth dearth” has a sharp rise in the proportion of older people. They consume an increasingly larger share of medical care, government pension funds, and other costly public services funded by a decreasing number of working taxpayers. Such countries can also face labour short- ages unless they rely more on greatly increased automation or immigration of foreign workers.

What Are Some Effects of Population Decline from a Rise in Death Rates? The AIDS Tragedy

Globally between 2000 and 2050, AIDS is projected to cause the premature deaths of 278 million people in 53 countries—38 of them in Africa.

AIDS kills many young adults. This change in the age structure of a country has a number of harmful effects. One is a sharp drop in average life expectancy. Another effect is a loss of a country’s most productive young adult workers and trained personnel such as scientists, farmers, engineers, teachers, and government, business, and health-care workers.