In geography, we love a good visual image, graph, model, or whatever is nice to look at when presenting data! The demographic transition model does just that; a visual aid to help describe the differences in population rates across the world. Dive on in to learn more about what the demographic transition model is, the different stages and examples, and the strengths and weaknesses that this model brings to the table. For revision, this one will be needed to be stuck on your bathroom mirror, so you don't forget it!
Demographic transition model definition
So firstly, how do we define the demographic transition model? The demographic transition model (DTM) is a really important diagram in geography. It was coined by Warren Thompson, in 1929. It demonstrates how the population (demographic) of countries fluctuate over time (transition), as birth rates, death rates, and natural increase change.
Population levels are actually one of the critical Measures of Development and can indicate whether a country has a higher or lower level of development but we'll talk about this more later on. Firstly, let's have a look at what the model looks like.
Fig. 1 - The 5 stages of the demographic transition model
We can see that the DTM is split into 5 stages. It has four measurements; birth rate, death rate, natural increase and total population. What exactly does this mean?
Birth rates are the number of people that are born in a country (per 1000, per year).
Death rates are the number of people that have died in a country (per 100, per year).
The birth rate minus the death rate calculates whether there is a natural increase, or a natural decrease.
If birth rates are really high, and death rates are really low, the population will naturally increase. If death rates are higher than birth rates, the population will naturally decrease. This consequently affects the total population. The number of birth rates, death rates, and therefore natural increase, determine which stage of the DTM a country is in. Let's take a look at these stages.
This image shows Population Pyramids too, but we won't talk about that here. Make sure you read our Population Pyramids explanation for information on this!
Stages of demographic transition model
As we have discussed, the DTM shows how birth rates, death rates, and natural increase influence the total population in a country. However, the DTM includes 5 very important stages that countries progress through, as these population figures change. Simply, as the country in question goes through the different stages, the total population will rise, as birth rates and death rates change. Take a look at the more simple image of the DTM below (this one is easier to remember than the more complicated one above!).
Fig. 2 - Simpler diagram of the demographic transition model
The different stages of the DTM can indicate the levels of development within a country. Make sure you read our measure of development explanation to understand this a little better. As a country progresses through the DTM, the more developed they become. We'll discuss the reasons for this in each stage
Stage 1: high stationary
In stage 1, the total population is relatively low, but birth rates and death rates are both very high. Natural increase doesn't occur, as the birth rates and death rates are somewhat balanced. Stage 1 is symbolic of less developed countries, that haven't gone through the processes of industrialisation, and have a much more agricultural-based society. Birth rates are higher due to limited access to fertility education and contraception, and in some cases, religious differences. Death rates are very high due to poor access to health care, inadequate sanitation, and higher prominence of diseases or issues like food insecurity and water insecurity.
Stage 2: early expanding
Stage 2 involves a population boom! This results from a country beginning to show signs of development. Birth rates are still high, but death rates go down. This results in a higher natural increase, and therefore total population rises dramatically. Death rates go down due to improvements in things like healthcare, food production, and water quality.
Stage 3: late expanding
In stage 3, the population is still increasing. However, birth rates begin to reduce, and with lower death rates too, the pace of natural increase starts to slow. The decline in birth rates can be because of improved access to contraception, and changes in the desire to have children, as changes in gender equality influence whether women may or may not stay at home. Having bigger families isn't so necessary anymore, as industrialisation occurs, fewer children are needed to work in the agricultural sector. Fewer children are also dying; therefore, births are reduced.
Stage 4: low stationary
In the more historical model of the DTM, stage 4 was actually the final stage. Stage 4 still shows a relatively high population, with a low birth rate and a low death rate. This means that the total population doesn't really rise, it stays pretty stagnate. However, in some cases, the population may begin to decline, as a result of fewer births (because of things like a reduced desire for children). This means there is no replacement rate, as fewer people are being born. This decline can actually result in an ageing population. Stage 4 is usually associated with much higher levels of development.
The replacement rate is the number of births that needs to take place to keep a population stable, i.e., the population essentially replaces itself.
An ageing population is a rise in the elderly population. It's directly caused by fewer births and an increased life expectancy.
Life expectancy is the amount of time someone is expected to live. Longer life expectancies stem from better healthcare and better access to food and water resources.
Stage 5: decline or incline?
Stage 5 can also represent decline, where the total population isn't replacing itself.
However, this is contested; look at both of the DTM images above, which show uncertainty about whether the population is going to rise again or fall even further. The death rate remains low and stable, but fertility rates could go either way in the future. It could even depend on the country that we are talking about. Migration could also influence the population of a country.
Demographic transition model example
Examples and case studies are just as important as models and graphs for us geographers! Let's have a look at some examples of countries that are in each of the stages of the DTM.
- Stage 1: In the present day, no country is actually considered in this stage anymore. This stage may only be representative of tribes that may live far away from any major population centres.
- Stage 2: This stage is represented by countries with very low levels of development, such as Afghanistan, Niger, or Yemen.2
- Stage 3: In this stage, development levels are improving, such as in India or Turkey.
- Stage 4: Stage 4 can be seen in much of the developed world, such as the United States, the majority of Europe, or countries in the oceanic continent, like Australia or New Zealand.
- Stage 5: Germany's population is predicted to drop by the middle of the 21st century, and drastically age. Japan, too, is a good example of how stage 5 could represent decline; Japan has the oldest population in the world, the longest life expectancy globally, and is experiencing population decline.
The UK went through each of these stages too.
- Starting off in stage 1 like every country
- The UK hit stage 2 when the Industrial Revolution began.
- Stage 3 became prominent in the early 20th century
- The UK is now comfortably at stage 4.
What will come next for the UK in stage 5? Will it follow the trends of Germany and Japan, and go into population decline, or will it follow other predictions, and see a population rise?
Demographic transition model strengths and weaknesses
Like most theories, concepts, or models, there are both strengths and weaknesses to the DTM. Let's take a look at both of these.
| Strengths | Weaknesses |
| The DTM is generally very easy to understand, shows simple change over time, can be easily compared between different countries across the world, and shows how population and development go hand in hand. | It's based entirely on the west (Western Europe and America), therefore projecting onto other countries around the world may not be very reliable. |
| Many countries follow the model exactly how it is, such as France, or Japan. | The DTM also doesn't show the speed at which this progression will take place; the UK, for example, took roughly 80 years to industrialise, in comparison to China, which took roughly 60. Countries that struggle to develop further may be stuck for a long time in stage 2. |
| The DTM is easily adaptable; changes have already been made, such as the addition of stage 5. Future additions of more stages could also be added, as the population fluctuates further, or when trends start to become more apparent. | There are many things that can affect the population in a country, that are ignored by the DTM. For example, migration, wars, pandemics, or even things like government intervention; China's One Child Policy, which limited people in China to have one child only from 1980-2016, offers a good example of this. |
Table 1
Demographic Transition Model - Key takeaways
- The DTM shows how total population, birth rates, death rates, and natural increase in a country, change over time.
- The DTM can also demonstrate a country's level of development.
- There are 5 stages (1-5), representing different population levels.
- There are numerous examples of different countries at different stages within the model.
- Both strengths and weaknesses exist for this model.
References
- Figure 1 - Stages of the Demographic Transition Model (https://commons.wikimedia.org/wiki/File:Demographic-TransitionOWID.png) Max Roser ( http://ourworldindata.org/data/population-growth-vital-statistics/world-population-growth) Licensed by CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
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