UN POPULATION PROJECTIONS ASSUMPTIONS
The UN has several different projections when calculating population growth of countries, regions or
continents. They include:
 Low fertility: Countries with total fertility at or below 2.1 (replacement rate) children per women in
2005-10. It is expected that total fertility will reach 1.85 by 2045-50.
 Medium fertility: Where fertility is declining, but is still above 2.1 in 2005-10.
 High fertility: Countries which have had no, or very little decline in fertility. Fertility is at least 0.5
above the medium fertility countries.
 Instant-replacement-fertility: Where fertility in 2005-10 is at a level to maintain existing population
(replacement rate).
 No-AIDS assumption: Where AIDS/HIV does not have a large affect on the mortality of a country.
 High AIDS assumption: When a country has a high instance of AIDS/HIV. A small infection decrease
will be projected as education and medical improves
 AIDS vaccine assumption: What is expected to happen if a AIDS/HIV vaccine is discovered during the
projection period.
When making a projection more than one assumption will be combined i.e. a country has low fertility,
no HIV/AIDS and high immigration.
GENERAL ASSUMPTIONS:
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The total fertility of all countries will eventually converge towards 1.85 (below replacement rate).
Fertility models are carefully checked against current trends in a country e.g. is there a massive
investment in birth control.
International migration is set on the basis of past international migration estimates and
consideration of the policy stance of each country with regard to future international migration
flows.
Mortality is expected to see smaller declines and life expectancy small increases.
QUESTIONS
Describe the changes in Europe’s, Africa’s and Asia’s population between 2000 and 2050. Remember to
include dates, figures, general trends and any anomalies.
1. Explain why you think Europe’s and Africa’s population projections are so different (think about
factors that may affect fertility and mortality).
2. Why do you think the UN does projections and why might they be useful?
3. Explaining how the following could have an affect on any UN projections:
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War
Natural disasters
Disease
Cure for a major disease e.g. malaria,
cancer or HIV
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Climate change
Investment in education
Investment in family planning
(development of new contraceptives)
Rapid economic development or
decline
TIP: Remember to think in terms of migration as well as mortality and fertility.