who created the demographic transition model (dtm)
Demographic transition Demographic transition (DT) is the transition from high birth and death rates to lower birth and death rates as a country or region develops from a pre-industrial to an industrialized economic system. The theory was proposed in 1929 by the American demographer Warren Thompson,[1] who observed changes, or transitions, in birth and death rates in industrialized societies over the previous 200 years. Most developed countries have completed the demographic transition and have low birth rates; most developing countries are in the process of this transition.[2][3] The major (relative) exceptions are some poor countries, mainly in sub-Saharan Africa and some Middle Eastern countries, which are poor or affected by government policy or civil strife, notably, Pakistan, Palestinian territories, Yemen, and Afghanistan.[2]