Ignoring migration, which shape describes an age structure likely to increase in size?

• A. Inverse pyramid
• B. Pyramid
• C. Circle
• D. Rectangle

Answer: (B)

Populations grow when there are many young people who will enter their reproductive years. A broad-based age structure, shaped like a pyramid with lots of youngsters at the bottom, signals that more births are likely in the future. If migration is ignored, those births push the total population upward as the young cohorts age and continue to reproduce, so the size of the population is expected to increase.

An inverted pyramid would indicate more older people and fewer young, suggesting a shrinking or aging population. A rectangle implies a stable number of people across age groups, and a circle isn’t a typical representation for growth trends in this context.