Development, population change and the demographic transition model
Social indicators such as birth and death rates can be used to identify levels of development.
Birth and death rates are also used as social development indicators. As HICs have developed, their birth and death rates have decreased over time. This data has been used to develop a model showing how population changes as a country develops. This is known as the demographic transition model (DTM). This model is shown below:
In stage 1 (high stationary) birth rates and death rates are very high. This is largely due to poor health care provision, a lack of contraception and the need for large families as infant mortality rates are very high. Only a few remote communities are at stage 1 of the DTM.
Low-income countries (LICs) are typically at stage 2 of the demographic transition model. Death rates are falling due to global approaches to tackling malnutrition and disease. Birth rates remain high due to high infant mortality rates, some children will not survive so families are large, a lack of contraception and children are needed to earn money working.
Newly emerging economies (NEEs) are mostly found in stage 3 of the demographic transition model. Birth rates are rapidly declining as fewer people live a subsistence lifestyle (growing their own food to survive) so children are not needed to work the land. Contraception is also widely available due to improvements in healthcare.
High-income countries are typically found in stage 4 of the demographic transition model. This is because improvements in healthcare and lifestyle lead to low death rates. The improved status of females means more women have careers and fewer children. Childcare is also expensive! The most developed countries are in stage 5 where birth rates fall below death rates. Japan and Germany are examples of where this is the case.
Sometimes there are anomalies in these patterns. This is because birth and/or death rates may suddenly increase as a result of a natural disaster or war. Also, some high-income countries are experiencing an increase in death rates due to an ageing population (a greater proportion of elderly people).
Rapid population growth occurs in LICs in stage 2 of the demographic transition model due to high natural increase. A population explosion occurs during this stage as shown in the model above. This is because the death rates are falling, but birth rates remain high. The UK experienced a population explosion as it entered stage 2 in the 1800s. India, however, experienced it between 1950 and 2000.
As countries across the world develop, the rate of global population increase is slowing and is expected to peak at 9 billion people in around 2050.
Overpopulation, caused by rapid population growth, puts immense pressure on land and resources. It can cause falling incomes, land degradation (e.g. desertification) and reduced health and happiness.
Overpopulation is rarely the sole cause of problems associated with population growth. For example, in Ethiopia, during the 1980s, the country experienced a major famine. However, this was not just caused by rapid population growth, drought and civil war also contributed to the problems experienced at this time.
Rapid population growth can also bring many positives. As countries develop economically, the demand for people to work in growing industries is increasing.
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