The Demographic Transition Model is a partially fact based, partially theoretical model that shows birth, death rates and population over time. There are 5 different stages involved in it and almost every country applies to a particular one of those stages, for example The USA is currently in stage 4 as its birth and death rates are quite low and constantly overtaking each other while the population is still rising reasonably quickly. Like any model it has its strengths and its weaknesses.
In terms of studying the graph, it is very simple and clear in terms of the way it is put together visually and the basis of the theory itself. It is especially good as every country can be put on it and has a specific stage that relates to it, whether it’s the USA in Stage 4 or Afghanistan in Stage 2. It is also very good as all countries relating to it means that the population change of countries in the future can predicted with reasonable accuracy. The model can also be added to when countries begin to go into the inevitable but as of yet unknown stages 6 and 7 the model can be updated with ease. Due to its accuracy, knowing the current stage of a country can also allow you to easily see the history of its population very well.
The diagram does have its flaws however. One of these is that despite it applying well to most countries, some are developing extremely rapidly with a good example being South Korea which although experiencing the stages, has done so much faster than would be expected due to almost overnight breakthroughs in industry and medicine which has helped my its vast Americanisation. Another issue is that the diagram supposedly shows development, with the countries in the later stages being the most developed. However due to cultural or religious reasons many countries that are very developed have high birth rates which means they can’t progress to the later stages. Many countries have also altered their birth rates artificially such as China with the one child policy has slowed down the birth rate significantly while the death rate continues to be high, this has made it difficult to place China on the DTM. possibly the main issue however is that DTM models for individual countries work on the basis that high birth rate are the only cause of increasing population, this is untrue however as many countries such as the UK are increasing in population rapidly because of migration. Therefore the population line does not work in conjunction with the birth and death rate lines.
To conclude, the Demographic Transition Model is clearly a very useful way of predicting the population change to a country to an extent, however several issues with it that are unresolvable mean that it can’t be trusted completely. There is no denying however that it still has its uses and there is no obvious alternative to it.