Page 49 - Demo

Module 8 Population Composition 127pyramid may face the challenges of educating the young and creating jobs. They also have the momentum for future growth as the large number of young people grow into their reproductive years and start their own families, regardless of how small those families may be compared to the families of earlier generations.Slow GrowthWhen a country%u2019s population growth slows down (the birth rate is just over death rate), its population pyramid will have a somewhat narrow base, but it may still be slightly pyramid shaped or cylindrical. The graph for China in Figure 8.7 is a good example of a slow-growth population pyramid. Its narrower bottom part reflects the smaller numbers of young people as a result of China%u2019s strict birth-control policies. Population will gradually age in slow-growth countries. Meeting the health care needs of a growing elderly population is an important challenge to those governments.StabilityWhen a country%u2019s population is stable%u2014that is, when its birth rate and death rate are similar%u2014and population growth approaches zero, its population pyramid will have a fairly even distribution across all cohorts. The U.S. population is still growing, but at a very slow pace. Its population pyramid, shown in Figure 8.7, looks more like a precariously balanced pillar. Also note that in the advanced age cohorts, the male side is narrower than the female side because women live longer than men.DeclineThe population pyramid for a declining population has a very narrow base or appears top heavy. For example, Spain%u2019s population pyramid in Figure 8.7 reveals a low birth rate and negative population growth. This population decline is also occurring in other developed countries, including Japan, South Korea, and most European countries. These countries may experience population aging, labor shortage, and declining demands for consumer goods and services.Unusually Shaped Population PyramidsSome population pyramids have an atypical or unusual shape due to certain events, policies, or trends that changed the age-sex structure drastically. For example, several Persian Gulf states, such as Qatar, the United cohorts on the vertical axis. We place the male percentages on the left-hand side of the graph and the female percentages on the right-hand side. (Figure 8.7).Four Typical Shapes of Population PyramidsA population pyramid is a snapshot of a population%u2019s age and sex structure at a particular time, but its shape also reveals past population changes that resulted from major events, such as the introduction of medical technologies and sanitation methods (which reduce death rates), wars (which may lead to significantly fewer males in some cohorts), large-scale famine and diseases (which lead to small cohorts), and baby booms after wars (which lead to a %u201cbulge%u201d in the population). By carefully examining a population pyramid, we can learn how the population has been growing, identify periods of baby boom or bust, determine whether the sex ratio is balanced at different age cohorts, calculate the country%u2019s dependency ratio, and discover if the population is aging. We can also predict future population trends.Most population pyramids have one of four typical shapes that reveal rapid growth, slow growth, population stability, or population decline.Rapid GrowthThe pyramid for a rapidly growing population has a wide base, resembling the classic stepped pyramid shape. Rapid population growth usually occurs in developing countries where birth rates are relatively high and there is a large number of young people in the population. The population pyramid for Tanzania in Figure 8.7 is a good example. Because people in developing countries do not live as long as people in developed countries, the sides of the pyramids may taper off relatively quickly to form a narrow top, reflecting the small populations in advanced age groups. Countries with a broad-based population AP%u00ae Exam TipBe prepared to explain demographic issues confronting a population (population decline, growth, etc.) by examining the population pyramid as your only piece of information. There is a lot of information about patterns in birth rates, death rates, and fertility rates in population pyramids once you can recognize the patterns.%u00a9 Bedford, Freeman & Worth Publishers. For review purposes only. Do not distribute.