In AP Human Geography, there are key models that you need to be familiar with across the different units. One model that you absolutely, positively, must know is the demographic transition model (DTM). The DTM is used to analyze patterns in the growth and decline of population as countries have developed. There are five stages of development, with most countries today between stages 2 and 4. As a country transitions into more developed stages, they experience massive decreases in the birth and death rates because of advances in technology, medicine, and contraceptives. All of these factors lead to a natural increase in population.
In this review, we’ll discuss the factors that lead to the changes in population and the effects of these transitions. In addition, we look at a specific case study for each stage to review examples and consider cause and effect for each stage. There have been several questions about the DTM on previous exams and in this review, we’ll also practice an FRQ on the DTM.