A concept in demography that elucidates the transition from high to low birth and death rates as a country or a region develops from a pre-industrial to an industrialized economic system
The demographic transition refers to the theory regarding the transition occurring in a population in a country or a region. Accordingly, as societies grow increasingly wealthy, the tendency of the birth and death rates is to decline. Initially, there is a high birth and death rates (stage one). The death rates and birth rates are high and about the same. This occurs in a pre-industrial society. As the society is progressing (developing), the death rates drop quickly (stage two). Possible cause of the decline is the improvement in food and sanitation, which in turn reduces risk of contracting diseases and relatively longer life expectancies. This is next followed by a decline in birth rates (stage three). Possible factors that curbed the rate of births are the increase in wages, access to contraceptive methods, urbanization, improved status of women, and other social changes. At this time, the growth of population starts to level off. This phase is followed by the decline in both the birth rates and the death rates (stage four). At this stage, there is a risk of shrinking population.
This theory was proposed by Warren Thompson, an American demographer, in 1929.