The demographic transition model five stages of population change.
The demographic transition model, or DTM, tracks how a country’s birth and death rates change across five stages as it develops. Here is the AP Human Geography definition, the five stages, and the mistake students make most.
The one-line definition
The demographic transition model, or DTM, describes how a country’s birth and death rates change as it develops, moving through five stages from high-and-stable to low-and-declining population.
The demographic transition model AP Human Geography definition that earns points is short: a five-stage model of how birth and death rates fall as a country industrializes and develops.
The five stages
Each stage is defined by what birth and death rates are doing.
Why it matters in AP HuG
The DTM is central to the population and migration unit and connects to population pyramids, dependency ratios, and policy. The key driver to remember is that death rates fall first, in Stage 2, which is what causes the population explosion, and birth rates fall later, in Stage 3, as societies urbanize and women gain education and work. Expect to place a country or a pyramid into the right stage.
Common mix-ups
Students often flip the order of falling rates. Death rates drop first, in Stage 2, which is why population surges; birth rates drop second, in Stage 3, which is why growth then slows. Also remember Stage 5 is debated and optional in some textbooks, used for countries with shrinking populations.
Frequently asked questions
Quick answers — written by humans, not a chatbot.
What is the demographic transition model?
A five-stage model of how a country’s birth and death rates change as it develops, moving from high-and-stable population to low-and-declining.
What happens in Stage 2 of the DTM?
Death rates fall sharply due to better food, healthcare, and sanitation, while birth rates stay high, producing rapid population growth.
Which countries are in Stage 5 of the DTM?
Countries with birth rates below death rates and shrinking, aging populations, such as Japan, Germany, and Italy. Stage 5 is optional in some textbooks.