Describe how the structure of a country’s population changes between stages 2 and 4 of the Demographic Transition Model

From rapid growth in stage two, the population stagnates or even declines when it reaches stage four.

Explanation:

Stage two of the Demographic Transition Model is the stage when a society moves out of primitive lifestyle and starts to develop, especially economically and in the health care services available. This results in a rapid increase in the population as the birth rates remain very high, while death rates decline significantly. Marriages still happen very early in people's lives.

When a population reaches stage four of the Demographic Transition Model, the demographic trends are much different. The population is standing very well economically, with a focus on career, later marriage, and having little or even no children. Medical care and lifestyle are of the highest quality so people live longer. This leads initially to stagnation of the population while it gradually ages, and then starts to decline because of the very low birth rates.