The Demographic Transition Model was developed by the American demographer Warren Thompson in 1929. DTM depicts the demographic history of a country. It refers to the transition from high birth and high death rates to low birth and low death rates regime as a country develops from a pre-industrial to an industrialized economic system.
The five stages of the demographic transition model
Stage One: The Pre-Industrial Stage (highly fluctuating – high stationary)
- Both birth rate and death rate are high
- Population fluctuates due to incidence of famine, disease and war.
- High infant mortality and very low life expectancy.
- Rural societies dependent on subsistence agriculture.
- Total population is low and balanced due to high birth rates and high death rates.
Example: No country as a whole at present retains the characteristics of
stage 1. However, it applies only to the most remote societies on earth such as the isolated tribes in Amazon with little or no contact with the outside world.
All human populations are believed to have had this stage until the late 18th century, when many countries in Western Europe were able to cross this stage.
Stage Two: The Industrial Revolution (early expanding) –very rapid increase
- Death rate falls sharply due to improvements in health care and sanitation. Birth rates remain high. Total population grows very quickly.
- Improvement in farming technology and increase in food supply
- Better nutrition, water supply, sewage, and personal hygiene and improvement in public health system .
- Increase in female literacy combined with public health education programs
Example: poorest developing countries like Afghanistan, Pakistan, Bolivia, sub-Saharan countries such as Niger, Uganda and middle east countries like Yemen, Palestinian Territories are still in stage 2.
Stage Three: Post-Industrial Revolution (late expanding) –increase slows down
- Birth rate falls due to the availability of contraception.
- Reduction of child labour- fewer children being needed to work in farm due to mechanization of farming
- Death rate stays at low level due to improved health conditions
- An increase in the status and education of women
- Total population still rises rapidly due to population momentum.
- The gap between birth and death rates narrows down
Example: Most developing countries that have registered significant social and economic advances are in stage 3, such as Costa Rica, Panama, Jamaica, Mexico, Colombia, Ecuador, Philippines, Indonesia, Malaysia, Sri Lanka, Turkey, Azerbaijan, Turkmenistan, Uzbekistan, Egypt, Tunisia, Algeria, Morocco, Lebanon, South Africa, India.
On the way:South Africa, Zimbabwe, Botswana, Swaziland, Lesotho, Namibia, Kenya and Ghana have begun to move into stage 3
Stage Four: Stabilization (low stationary) – very slow increase
- Birth control is widely available and there is a desire for smaller families.
- Both birth and death rate are low
- Total population is still high, but it is balanced by a low birth rate and a low death rate.
Example: Newly industrialized countries such as South Korea and Taiwan have just entered stage 4.United States, Canada, Argentina, Australia, New Zealand, most of Europe, Bahamas, Puerto Rico, Trinidad and Tobago, Brazil, Singapore, Iran, China, Turkey, Thailand and Mauritius
Stage Five: Declining population
- Low birth rate along with an aging population leads to declining population
- Death rates may remain consistently low or increase slightly due to increases in lifestyle diseases like obesity, stress and diabetic.
- Birth rates may drop to well below replacement level
Example: Countries like Germany, Italy, Japan, Russia leading to a shrinking population
What happens to birth and death rates?
As populations move through the stages of the model, the gap between birth rate and death rate first widens, then narrows. In stage 1 the two rates are balanced. In stage 2 they diverge, as the death
rate falls relative to the birth rate. In stage 3 they converge again, as the birth rate falls relative to the death rate. Finally in stage 4 the death and birth rates are balanced again but at a much lower level.
The demographic transition model shows the changes in the patterns of birth rates and death rates that typically occur as a country moves through the process of industrialization or development. The demographic transition model was built based on patterns observed in European counties as they were going through industrialization. This model can be applied to other countries, but not all countries or regions fit the model exactly. And the pace or rate at which a country moves through the demographic transition varies among countries.
In the demographic transition model, a country begins in Stage 1, the preindustrial stage. In Stage 1 (Figure \(\PageIndex{1}\)), both birth rates and death rates are high. The high death rates are because of disease and potential food scarcity. A country in Stage 1 of the demographic transition model does not have good health care; there may not be any hospitals or doctors. Children are not vaccinated against common diseases and therefore many children die at a young age. Infant and childhood mortality rates (death rates) are very high. A society in Stage 1 is likely based upon agriculture and most people grow their own food. Therefore, droughts or flood can lead to widespread food shortages and death from famine. All of these factors contribute to the high death rate in Stage 1. Partly to compensate for the high death rates, birth rates are also high. High birth rates mean that families are large and each couple, on average, has many children. When death rates are high, having many children means that at least one or two will live to adulthood. In Stage 1, children are an important part of the family workforce and are expected to work growing food and taking care of the family.
As you are examining the stages of the demographic transition model, remember that:
\[\text{Population Growth Rate} = \text{Birth Rate} – \text{Death Rate} \nonumber\]
In Stage 1, birth rates are high, but death rates are high as well. Therefore, population growth rate is low or close to zero (Figure \(\PageIndex{2}\)).
As a country develops, medical advances are made such as access to antibiotics and vaccines. Sanitation improvements, such as proper waste and sewage disposal, and water treatment for clean drinking water also progress. Food production also increases. Together these changes lead to falling death rates which marks the beginning of Stage 2 (Figure \(\PageIndex{1}\)). Death rates continue to fall throughout Stage 2 as conditions improve. This means that people are living longer and childhood morality drops. However, birth rates are still high in Stage 2. There is a time lag between the improving conditions and any subsequent changes in family size, so women are still having many children and now more of these children are living into adulthood. In Stage 2, the birth rate is higher than the death rate, so population growth rate is high. This means that population size increases greatly during Stage 2 of the demographic transition model (Figure \(\PageIndex{2}\)).
A falling birth rate marks the beginning of Stage 3 in the demographic transition model. As a country continues to industrialize, many women join the workforce. Additionally, raising children becomes more expensive and children no longer work on the family farm or make large economic contributions to the family. Individuals may have access to birth control and choose to have fewer children. This leads to a drop in birth rates and smaller family sizes. Death rates also continue to drop during Stage 3 as medicine, sanitation and food security continue to improve. Even though both birth rates and death rates are falling throughout Stage 3, birth rates are higher than death rates. This means that population growth rate is high and that population size continues to increase in Stage 3 of the demographic transition model (Figure \(\PageIndex{2}\)).
Birth rate and death rates drop to low, stable, approximately equal levels in Stage 4. Death rates are low because of medical advances, good sanitation, clean drinking water and food security. Birth rates are low because of access to birth control and many women delay having their first child until they have worked. Childhood mortality is low, life expectancy is high, and family size is approximately two children per couple. With low birth rates and low death rates, population growth rate is approximately zero in Stage 4 (Figure \(\PageIndex{2}\)).