AP HUG Unit 2.3

Population composition

The demographic makeup of a population, focusing primarily on age structure and ratio.

Demographics

The characteristics of a population, such as age, sex, ethnicity, education, and income.

Which two demographic characteristics are emphasized in AP Human Geography?

Age structure and ratio.

Age structure

The organization of a population into different age groups (cohorts).

Cohort

A group of people within the same age range.

Why is age structure important?

It helps geographers determine whether a population is growing, stable, or declining and predict future needs.

Dependency ratio

The number of dependents (under 15 and over 65) compared to the working-age population (ages 15–64).

What does a high dependency ratio indicate?

A greater burden on the working-age population to support dependents.

Sex ratio

The comparison of the number of males to females in a population.

Why does China have an unusually high male-to-female ratio?

A cultural preference for sons combined with the One-Child Policy led to fewer female births.

Population pyramid

A graph that displays a population's age structure and sex ratio.

What do the axes of a population pyramid represent?

Y-axis = age cohorts; X-axis = population by sex (males on the left, females on the right).

Why do geographers use population pyramids?

To predict future population growth and identify demographic challenges.

Rapid-growth population pyramid

A pyramid with a wide base and narrow top, indicating high birth rates, lower life expectancy, and rapid population growth.

Slow-growth population pyramid

A pyramid where birth rates are declining but still exceed death rates, resulting in continued but slower population growth.

Stable-growth population pyramid

A pyramid with nearly equal birth and death rates, resulting in little or no population growth.

Declining population pyramid

A pyramid with a narrow base and a wider upper section, indicating low birth rates and an aging population.

Major challenge of a declining population

Labor shortages caused by more people retiring than entering the workforce.

How can you identify a rapid-growth population pyramid?

A very wide base with a narrow top.

How can you identify a declining population pyramid?

A narrow base with a relatively wider middle and upper section.

What does the shape of a population pyramid reveal?

Whether a population is growing rapidly, growing slowly, stable, or declining.