1. Demographic Transition Model

2. What Is It? The relationship between birth rate and death rate has been used to create a four stage model of a country's population change, called the demographic model. Countries which are described as being developed have reached Stage 4. The UK is one of these. Other countries are at different stages of their development, and therefore occupy different places on the model.

3. Stage 1 High birth rate (BR) and high death rate (DR), both around 35 per 1000. This means a relatively slow population growth. High BR due to no contraception and the need for large families. High BR due to diseases, poor health care, poor water quality, and a poor food supply. The UK was at this stage in the period up to 1750. Only a few remote indigenous tribes, in places such as the Amazon rainforest, exhibit these characteristics nowadays.

4. Stage 2 BR remains high, at around 35 per 1000, but DR falls to about 20 per 1000 by the end of the stage. The DR falls due to improvements in health care, sanitation and water quality. There is also increased access to medicines and food. The UK was in this period between 1750 and 1880. Countries such as Bangladesh, Libya and Nigeria are currently in this stage of their development.

5. Stage 3 BR falls rapidly to near 20 per 1000, and DR continues to slowly fall to around 15 per 1000. The fall in the BR is due to better access to contraception, more family planning education, working women getting married and having children later, less need for children as a labour source. DR continues to fall as health care improves further, and sanitation conditions improve. The UK was in this stage between 1880 and 1950. Countries passing through this stage at present include China and Argentina.

6. Stage 4 BR and DR low, at under 10 per 1000. Although there may be some annual fluctuations population growth is close to zero. The UK is in this stage at the moment, along with countries such as the United States and Japan.

7. Stage 5 It has been suggested that a new fifth stage should be added to the model, due to some countries, such as Sweden and France, having higher DR than BR, so that their populations are actually falling.