Age structure diagrams - slps.org

A way of predicting population changes AGE STRUCTURE DIAGRAMS POPULATION STRUCTURE The population pyramid displays the age and sex structure of a country or given area Population in Five Year Age bands MALES To the left

Usually, but not always, In % to make for easier comparisons between countries FEMALES To the right What Population Pyramids Show Us Economically More Developed Country

Economically Less Developed Country KEY slope of pyramid indicate the death rate width of the base is related to birth rate/fertility rate proportions of men and women can suggest male or female migrations height of graph can indicate life expectancy (ignore the very thin end of the wedge as occurs on graph B as these people are a definite minority) "kinks" indicate dramatic reductions in birth rate or increases in death rate in the past area of graph indicates total population - compare areas of different population age groups or different sex on one graph

The overall shape of the population pyramid can indicate whether it is an Economically More Developed Country or Economically Less Developed Country Population pyramid of a less developed nation (broad base population pyramid) Population Pyramid of Nigeria (1995) Importance of Population Pyramids A BROAD BASE POPULATION PYRAMID MEANS A COUNTRY SHOULD:

increase food production build more homes & schools plan for more job opportunities for the young in future implement birth control program/campaigns Usually agricultural population with problems of overpopulation. Population pyramid of a developed nation Population Pyramid of Sweden (1995) Importance of Population Pyramids

A NARROW BASED POPULATION PYRAMID MEANS: Birth rate and Death rate low so a country may need to: Work out incentives to encourage more births Begin hiring foreign labor Ensure proper medical services & health care for the aged Age Structure Diagrams Male Male Female Female

Rapid Rapid Growth Growth Guatemala Guatemala Nigeria Nigeria Saudi Saudi Arabia Arabia Ages Ages 0-14 0-14 Slow

Slow Growth Growth United United States States Australia Australia Canada Canada Ages Ages 15-44 15-44 Zero Zero Growth

Growth Spain Spain Austria Austria Greece Greece Negative Negative Growth Growth Germany Germany Bulgaria Bulgaria

Sweden Sweden Ages Ages 45-85+ 45-85+ Predict the future population change for each of the three age structure diagrams U.S. Population by age 1900, 2000, and 2050 projected Population structure by

age and sex in developed and developing countries. Tracking the baby-boom generation in the U.S. THOMAS ROBERT MALTHUS 1766-1834 Growth Potential of Subsistence Vs. Population

140 TIME 1 120 TIME 2 100 TIME 3

80 TIME 4 60 TIME 5 40 TME 7 TIME 6

20 0 SUBSISTENCE POPULATION TIME 7 supply (subsistence) grow at different rates Population will

outgrow food supply Results from the point of crisis include famine and war Population and food Basic Point From MALTHUS: What are advantages and disadvantages of reducing births: Controversy Can the worlds resources support an additional 2.5 billion

by 2050? Is the Earth overpopulated? Carrying capacity If yes, what should be done? What is a sustainable population?