33. Demographic indicators: measures describing population groups. Population pyramids
From greek.doctor
Dependency ratio is the ratio of the population who are economically inactive to those who are economically active:
Dependency ratio = population < 15 and > 65 / population between 15 and 65
Population size – the number of individuals in the population
Population density – the number of individuals in the population per unit of area
Age structure – the age structure of a population is shown by the population pyramid
Most developed countries have contracting population pyramids
Most developing countries have expanding or stationary population pyramids
Population pyramids
Population pyramids are formed according to age and gender
They change shape according to the epidemiological stage
Major demographic characteristics of developing countries
High fertility
High infant mortality
High prevalence of HIV/AIDS
High level of out-migration
Major demographic characteristics of developed countries
Low levels of fertility – often lower than the replacement level of 2.1
Women have babies at later ages
High level of in-migration
Trends in age groups
In Europe, people < 15 are decreasing, 15 – 60 are decreasing, > 60 are increasing rapidly
In Asia, people < 15 are stable, 15 – 60 are increasing rapidly, > 60 are increasing
In Africa, all age groups are increasing rapidly. 15 – 60 are increasing the fastest
The stages of epidemiologic transition
Describe the change from when our demographics were determined by epidemics and famines to now, where out demographics are mostly determined by non-communicable diseases, like cancer and cardiovascular disease
Pestilence and famine
High mortality rate, wide swings in mortality rate due to pestilence and famine, little population growth, low life expectancy
Receding pandemics
Epidemics and infectious diseases become less frequent, non-communicable diseases begin to appear
Degenerative and man-made diseases
Mortality due to non-communicable and man-made diseases becomes higher than mortality due to infectious diseases and famine
