The Demographic Transition Model And Population Pyramids in the Study of Population Growth The Problem The size, composition, and growth of population affect the economic and environmental well-being of nations. Rapid population growth in regions such as sub-Saharan Africa and the Middle East require huge commitments of national resources. Countries with declining growth rates may have large elderly populations that require large expenditures of resources to support. The Study Geographers and demographers use the Demographic Transition Model as a framework for understanding the dramatic variations in birth, death, and growth rates world wide. Based on the demographic history of European countries, the demographic transition model offers a generalized perspective of the way birth, death, and growth rates change through time. The Demographic Transition Model STAGE I A - Stage 1 Both high birth rates and death rates fluctuate in the first stage of the population model giving a small population growth (shown by the small total population graph). There are many reasons for this: little access to birth control many children die in infancy (high infant mortality) so parents tend to have more children to compensate in the hopes that more will live children are needed to work on the land to grow food for the family children are regarded as a sign of virility in some cultures religious beliefs (e.g., Roman Catholics and Hindus) encourage large families high death rates, especially among children because of disease, famine, poor diet, poor hygiene, little medical science. The Demographic Transition Model STAGE 2 B - Stage 2 Birth rates remain high, but death rates fall rapidly causing a high population growth (as shown by the total population graph). The reasons for this could be: improvements in medical care hospitals, medicines, etc. improvements in sanitation and water supply quality and quantity of food produced rises transport and communications improve the movements of food and medical supplies decrease in infant mortality. The Demographic Transition Model STAGE 3 C - Stage 3 Birth rates now fall rapidly while death rates continue to fall. The total population begins to peak and the population increase slows to a constant. The reasons for this could be: increased access to contraception lower infant mortality rate means there is less need to have a bigger family industrialization and mechanization means fewer laborers are required the desire for material possessions takes over the desire for large families as wealth increases equality for women means that they are able to follow a career path rather than feeling obligated to have a family. The Demographic Transition Model STAGE 4 D - Stage 4 Both birth rates and death rates remain low, fluctuating with 'baby booms' and epidemics of illnesses and disease. This results in a steady population. The Demographic Transition Model STAGE 5 E? - Stage 5? A stage 5 was not originally thought of as part of the DTM, but some northern countries are now reaching the stage where total population is declining and where birth rates have dropped below death rates. One such country is Germany, which has taken in foreign workers to fill jobs. The UK's population is expected to start declining by 2021. The Demographic Transition Model Limitations Although the demographic transition model is a compelling and an extremely useful framework for viewing contemporary population change, we must be careful in using it to predict the future of Third World countries currently in the second or third stages. Their economies and populations are so different from those of Europe that we cannot be sure their demographic transition will resolve in the same way.