Advanced Placement (AP) Human Geography Practice Exam

What does doubling time measure?

1. The time it takes for a country to reduce its population

2. The time needed for a country’s population to double

3. The rate of economic growth over a decade

4. The average lifespan of a population

The correct answer is: The time needed for a country’s population to double

Doubling time specifically measures the period required for a population to grow to twice its current size. This concept is crucial in understanding population dynamics, as it provides insight into how quickly a population is increasing. In demographic studies, factors such as birth rates, death rates, and migration are analyzed to project how long it will take for a population to double, assuming current growth trends continue. This metric helps policymakers and researchers anticipate future population pressures and plan accordingly for infrastructure, resources, and services to accommodate growth. The other options do not align with the definition of doubling time. The measurement of a country reducing its population, economic growth rates, or average lifespan are all distinct figures that serve different purposes in demographic and economic analysis. Thus, the focus on population increase distinguishes doubling time as a unique and important measure in human geography and demographic studies.