Which term describes a shift in the proportions of populations of various ages?

Which term describes a shift in the proportions of populations of various ages?

• A. Dependency ratio
• B. Demographic shift
• C. Young-old
• D. Wear and tear

Answer: (B)

The key idea is changes in the age makeup of a population over time. When birth rates, life expectancy, or migration alter how many people are in each age group, the overall age structure shifts. That broad change in the proportions of various ages is described as a demographic shift. Why this term fits best: it captures the idea that a population’s age distribution is not static but moves from one pattern to another—such as more older adults relative to younger ones or vice versa. The other options describe related ideas but not the overall change in age structure itself: the dependency ratio is a measure of how many dependents there are per working-age person, rather than the shift in age proportions; the term young-old refers to a specific subset of older adults, not the pattern of age distribution; wear and tear is an informal, non-technical concept about aging.

The key idea is changes in the age makeup of a population over time. When birth rates, life expectancy, or migration alter how many people are in each age group, the overall age structure shifts. That broad change in the proportions of various ages is described as a demographic shift.

Why this term fits best: it captures the idea that a population’s age distribution is not static but moves from one pattern to another—such as more older adults relative to younger ones or vice versa. The other options describe related ideas but not the overall change in age structure itself: the dependency ratio is a measure of how many dependents there are per working-age person, rather than the shift in age proportions; the term young-old refers to a specific subset of older adults, not the pattern of age distribution; wear and tear is an informal, non-technical concept about aging.