Figure 3.8: The demographic transition as a graph. The transition occurs in several stages as the industrialization of a country progresses. In stage 2 the death rate declines rapidly, causing a population explosion as the gap between the number of births and deaths widens. Then, in stage 3, the birthrate begins a sharp decline. The transition ends in stage 4, when both birth and death rates have reached low levels, by which time the total population is many times greater than at the beginning of the transformation. In the postindustrial stage, population decline eventually begins.