What is the function of a demographic transition model?

The function of a demographic transition model is to describe the transition of populations from high to low birth and death rates, a process that typically occurs as a society advances economically and socially. This model illustrates how populations change over time through distinct stages, beginning with high fertility and mortality rates and progressing towards lower rates.

In the first stage, both birth and death rates are high, resulting in a stable population. As a country begins to develop, many factors, such as improvements in healthcare and sanitation, contribute to a decline in death rates, leading to population growth. Subsequently, as economic conditions improve and social changes occur—such as increased access to education and contraceptive methods—birth rates also begin to fall. This transition reflects broader societal shifts, including urbanization and changing family structures, which are crucial for understanding population dynamics over time.

By analyzing these stages, demographers and policymakers can gain insights into potential future population changes, enabling them to plan for economic development, social services, and resource allocation. Thus, option B accurately captures the core purpose of the demographic transition model within the study of geography and population dynamics.