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Study the graph (left) and the map (below) and use them to describe and explain the patterns of ageing/greying worldwide. What are the reasons for the patterns you identify? Which regions and which classifications of country are experiencing ageing and why? Why is this not the case for some areas of the world? |
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Subject Guide
.Global and regional/continental trends in family size, sex ratios, and ageing/greying
A. Definitions
Family Size
This is the average number of children per family. A useful way to measure this is by examining changing fertility rates as these closely mirror the average family size. See this page.Demographic transition
Sex ratios
The sex ratio is a measure of how many males there are to females in a population. It is calculated by measuring the number of males in a population for every hundred females. So a national sex ratio of 98 would tell us that for every 100 females there were 98 males. A sex ratio greater than 100 indicates that a country has more males than females; a ratio of less than 100 shows that the country has more females than males.
Ageing/greying
This refers to an increase in the proportion of the population who are 65 or older. We an measure this by using the same approach as for old age dependency.
This is the average number of children per family. A useful way to measure this is by examining changing fertility rates as these closely mirror the average family size. See this page.Demographic transition
Sex ratios
The sex ratio is a measure of how many males there are to females in a population. It is calculated by measuring the number of males in a population for every hundred females. So a national sex ratio of 98 would tell us that for every 100 females there were 98 males. A sex ratio greater than 100 indicates that a country has more males than females; a ratio of less than 100 shows that the country has more females than males.
Ageing/greying
This refers to an increase in the proportion of the population who are 65 or older. We an measure this by using the same approach as for old age dependency.
B. Sex ratios
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According to the World Health Organisation, the natural sex ratio at birth is 105; in other words, for every 100 female babies born, there are 105 boys. This proportion is due to both biological and cultural factors. Biological factors include a range of influences on whether a sperm carrying an X or Y chromosome is more likely to fertilise an egg. Cultural factors include selective abortions of female foetuses in cultures where sons are valued more than daughters.
From https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5522a6.htm
Male death rates tend to be higher than female death rates (see life expectancy data above). This is for several reasons:
These factors mean that the overall global sex ratio is approximately 101.
- males tend to be more involved in risky behaviour than females (fighting, drinking and smoking)
- men are more likely to have jobs in risky occupations than women eg mining, trawlermen
- men are more likely to be killed in wars and combat than women
- depression and suicide rates tend to be x3.5-5% higher among men than women
These factors mean that the overall global sex ratio is approximately 101.
Sex ratios by country: the countries with the highest proportion of males. Data sourced from CIA.
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Sex ratios by country: the countries with the highest proportion of females. Data sourced from CIA.
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The world's lowest sex ratio is in Dijibouti. This is likely to be a result of the civil war which took place between 1991 and 2000 as well as significant economic migration of men. In Latvia, Lithuania, Russia, Ukraine and Belarus the low proportion of males is due to the remaining legacy of men lost in World War 2 and out migration.
The countries with the highest sex ratios are oil rich states where exceptionally high male in-migration of building workers has skewed the balance of the population. |
Choose one country with a high sex-ratio and one with a low sex ratio. For each, research the reasons further and present your findings in the document below.
C. Ageing/greying populations
D. Consequences of ageing/greying populations
Use the resources below to create an inforgraphic of the possible consequences of ageing populations. Make sure you identify the positives/opportunities as well as the negatives/challenges. Think about SEEP!
Possible infographic making sites
Examples of student infographics
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Daily Fail?
Look at the story below about UK population increases. As well as worrying about migration, the journalist says that some of the increases will be because there are more births. Look at the article and consider:
- What are the BLURS?
- How does the data presented in the population pyramid contradict what the journalist says?