Answer and Explanation:
Demographic data goes a long way to tell about the classifications of countries on level of development, according to whether a country is a Third World country or second or first. This is based on demographic transition as originated from Warren Thompson, a demograher, in 1929. Demographic transition explains population change and transition over time as observed in countries.
In the pre transition stage or stage one of the transition, there is high birth rate and death rate, while in the early stage transition(stage 2) there is high birth rate and decreasing death rate as compared to stage 1 which is notable of Third World countries .In the late transition(stage 3), there is decreasing birth rate and decreasing death rate.
stage 4 is the post transitional society characterized by low birth rate and death rate notable in industrialized countries or first world countries