Population Structure The Use of Indices                 Population Structure by Matthew Alfordis licensed under a Creative Commons Attribution 4.0 International License.

Young Dependents % + Old Dependents % The dependency Ratio The relationship between working population and dependent population. Young Dependents % + Old Dependents % Working Population % 100

Young Dependents % + Old Dependents % The Support ratio The inverse of the dependency ratio Working Population % Young Dependents % + Old Dependents % 100

The Juvenility index The proportion of younger people in a population % of population under 20 % of population over 20 100

The Old-age index 100 The proportion of elderly people in a population % of population over 60 % of population under 60 100

The indices Provide quantitative way of comparing population structures Simply describing age/sex diagrams is qualitative. Demographers use the indices more because they are objective, geographers use the qualitative methods that are more subjective.

The bigger the top bar on the pyramid, the better the life expectancy. CC BY Wikimedia Commons The bigger the top bar on the pyramid, the better the life expectancy. The slope of the side tells you about the death rate. A more vertical side means that young people are not expected to die. The balance between the three main age groups can tell you what the government’s priorities should be. The gender balance of a country is important. The bulges and dips on the side can tell you about migration or about birth-rate fluctuations. The bottom of the pyramid tells you about birth rates and infant mortality. A wide base means a high birth-rate.

More females than males, showing a longer female life expectancy. CC BY Wikimedia Commons More females than males, showing a longer female life expectancy. ‘Rectangular’ shaped pyramid indicates a low death rate. Still relatively large numbers, meaning a long life expectancy. Does not narrow indicating a very low infant mortality rate. Almost equal numbers of males and females. Narrowing base indicates a low and falling birth rate.

Complete the Indices Classwork INDICIES WORK Complete the Indices Classwork PD Wikimedia Commons