Population StructureThis is a featured page

What You Must be able to do for the exam

  • Interpret population pyramids
  • Be able to suggest problems created by a variety of population structures and offer soltuions to these problems
  • Be able to calculate dependency ratios and identify which country would be likely to have which dependency ratio (using the formula below
Non economically active/economically active x100 e.g. UK 2001 (11.105+9.341)/38.342 = 0.533333 x100 UK Dependency ratio=53.33

  • Interpret the DTM (including stage 5)

When we talk about population structure we mean the proportion of one age group i.e. those of working age as compared with the proportion of other age groups i.e. those too old to work.

Why are population structure graphs important?
Population structure is very important for governments to know so as they can see if there are enough people working to pay the taxes to look after those people who are not working i.e. the dependency ratio.

Governments are then in a position to make changes to help create the types of skills and jobs that their country needs e.g. train lots of nurses so as there enough people to look after the increasing old retired population.

They also a give an easy to understand visual explanation of how structured a country is. There are several different graphs which deal with different subjects, and all of which are very useful in information and accuracy.

The rate of natural increase, the birth rate, the death rate, and life expectancy are all factors that affect the population structure of a country.
Population Structure - Mclean Kids
This is an example of a populatipon structure of China and India. Their populations in 2007 and the predicted population in the year 2025. Population Structure - Mclean Kids
The diagram above shows the different growth of population in the countries. A rapid growth, slow growth and decline in growth of different countries. This diagram helps you understand what the structure looks like for a country with a certain growth. This indicates that less developed countries such as Nigeria have a much higher percentage of young people than highly developed countries. which mean that less developed countries have a larger population than more developed countries.

Age-Sex pyramids
  • They are very important to analyze population structure.
  • They show the total population that is divided into five-year age groups and the total population percentage that is subdivided into males and females for the age groups.
  • They enable comparisons between countries which helps a country plan future services. Population pyramids include immigrants as well.
There is a big difference between males and females as well as for different age groups.
Some nations have more women than men because men have to fight in wars. the working age is decimated while the again group stays the same since they cant be involved in the war.
It is typical that the years following war such as WW2, had a great increase in the population due to the government telling the citizens to produce more off springs.
Another effect of discrepancy in numbers of the two genders is China.

LEDC stands for Less economically developed countries, they are the non-industrialized nations or the third world countries. The countries are located mostly in southern hemisphere, and the countries are still in the early stages.
Example of less economically developed countries: Zambia, Kenya, Sudan, Ethiopia, Bangladesh, and Zimbabwe.

MEDC stands for more economically developed countries, they are the industrialized nations or the first world countries. The countries are in the northern hemisphere and they're advanced or have completed their development period.
Examples of more economically developed countries: England, US, Canada, France, and Germany.

The contrast between MEDC AND LEDC in terms of population pyramids, population growth and stage in the Demographic Transition Model (DTM) is that in many MEDC, the natural increase is low due to low birth rates and death rates. The stage it’s in is 4/5 and a MEDC population pyramid would have a small bottom, a large middle and small top. In LEDC there is a explosion of population due to high birth rates and lower death rates, the stage it’s in is 2/3. The population pyramid of LEDC would have a large bottom, gradual decrease upwards.

Terms for population structure
  • Crude birth rate, crude death rate, natural increase, and infant mortality rate.
  • Crude birth rate is the number of births per 1000 people in a year.
  • Crude death rate is the number of deaths per 1000 people in a year.
  • Natural increase is the number of extra people in percentage.
  • Infant mortality rate is the annual number of deaths of infants less than one year old per 1,000 live births.

The Demographic Transition Model (DTM)

the DTM is useful at showing changes in population over time as development occures. For each stage of the DTM we can create a population pyramid that accurately shows the population structure and therefore what population issues a country at each stage of the DTM will face. It shows a general trend of changes in significant factors which are birth rate, death rate, and indutrialization.

DTM originated from interpretation that Warren Thompson, an American demographer. He started to interpret and observe transitions in birth rate, death rate and industrialization of societies of past two centuries or so at 1929. [See example picture below.]

Population Structure - Mclean Kids
As seen in the image, there are total of 5 stages in the DTM.

○1st Stage- Pre-Modern Stage

-This stage reflects pre-modern countries where the birth rate and the death rate are approximately the same.

-At this stage, the overall population shows slight, very natural, and gradual increase.

-The main cause of the high death rate are the following:
1.Food shortage that happens occasionally
2.Unaware of lethal diseases

Example of a country in 1st stage:[Mali/2005]

File:Pyramide Mali.PNG

○2nd Stage- Urbanizing/ Industrializing Stage

-This stage reflects the industrializing/Urbanizing countries (Such as North West Europe in the late 18th century)

-The birth rate remains while the death rate starts to decrease.

-At this stage, the overall population mushrooms at first and the rate starts to stabilize as it goes on.

-This means that the causes of high death rate are being terminated(The two main cause are listed above in 1st stage 3rd point):
1. Food supplies were enhanced by agricultural development
2. Public health services were strengthened

Example of a country in 2nd stage:[KENYA/2005]
File:Pyramide Kenya.PNG

○3rd Stage- Mature Industrial Stage

-This stage reflects the countries which are already much developed

-At this stage, the population likely stabilizes in great degree by the fall of birth rate

-These are some factors that contribute to the decrease of birth rate:
1. People starts to realize that they don't need so many children to keep the generation
2. People prefer nuclear families than big families
[Nuclear family is a family structure that consists of parent and one or two children- it is also known as extended family]
3. People (Female) feel no need of child bearing and motherhood as they are educated and are hired

Example of a country in 3rd stage:[BRAZIL/2005]
File:Brazil population pyramid 2005.png

○4th Stage- Post Industrial Stage

-This stage reflects most of the developed countries nowadays.

-If the countries in this stage were analyzed with population pyramid, mid-age people would have been the primary population

-The death rate decreases rapider and faster than the decrease of birth rate

Example of a country in 4th stage:[JAPAN/2005]

File:Pyramide Japon.PNG

○5th Stage- Declining Stage

-This is a newly developed stage by the concern of some demographer that DTM needs alternation

-This stage reflects some of the developed countries such as Japan, Germany, Italy and so on.

-The birth rate drops faster than the death rate resulting in population decrease.

-Reasons for the birth rate drop are similar as the ones listed on 3rd point of 3rd stage.

-Also, Late marriages and advancing status of woman causes down fall of birth rate

Example of a country in 5th stage:[FINLAND/2005]
File:Pyramide Finlande.PNG

we can relate the population pyramid with the five stages in a way that the
causes of the five stages shapes the graph as it is explained in the characteristics
of the five different stages.


The New Wider World. David Waugh.

"Demographic transition." UW Marathon County - The Best Start for the Life You Want. 12 Apr. 2009 http://www.marathon.uwc.edu/geography/Demotrans/demtran.htm.

Geographyalltheway.com - Online Geography Resources. 12 Apr. 2009 http://www.geographyalltheway.com/igcse_geography/population_settlement/population/imagesetc

"Population Definitions." Standard Grade Geography. 12 Apr. 2009 http://www.scalloway.org.uk/popu5.htm.

12 Apr. 2009 http://www.ux1.eiu.edu/~cfruf/images/bio3002/popage4.gif.

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