Effects of Changing Population Sizes (CIE IGCSE Economics)

• Overpopulation occurs when there are more people in a country/region than can be supported by its resources & technology & leads to
  • Higher levels of pollution
  • Higher crime rates
  • Higher unemployment or underemployment
  • Higher levels of food & water shortages 
  • Higher pressure on services such as hospitals & schools
     
• Underpopulation occurs when there are more resources available than the population can use effectively & may lead to
  
  • Fewer people paying tax which can lead to higher taxes
  • Underused resources, which can lead to wastage
  • A shortage of workers
  • Lower levels of exports & production which affects the wealth of an area
  • Fewer customers for goods & services
     
• Optimum population occurs when there is a balance between the number of people & the resources/technology available
    
   

Optimum Theory of Population

  

• The optimum population results in the highest standard of living
  • There are not so many people or so few resources that the standard of living falls
  • There are enough people to develop the resources of the country 

• The characteristics of a population (the distribution of age, sex, ethnicity, religion etc), is known as the population structure
    
• The population structure is the result of changes in:
  • the birth rate
  • the death rate
  • net migration
     
• The two main characteristics of age & sex can be shown on a population pyramid

 

Population Pyramids

• Population pyramids are used to display the gender & age structure of a given population
  • They illustrate the distribution of population across age groups and between male/female
     
• Population pyramids can be used to identify the following groups:
  • Young dependents 
  • Old dependents e.g number of retired people
  • Economically active (working population or labour force)
  • Dependency ratio
     

Example 1 - Niger As A Less Economically Developed Country (LEDC)

Population Pyramid - Niger

• LEDCs like Niger have a concave pyramid shape which indicates
  • High birth rate
  • Low life expectancy
  • High death rate but starting to decrease (people dying through every age group)
  • High infant mortality rate (significant decrease between 0-5)
  • Young dependent population dominates the distribution
     

Example 2 - USA As A More Economically Developed Country (MEDC)
 

Population Pyramid - USA 

• This population pyramid indicates:
  • Decreasing birth rate  - there is a smaller population reading down from age 29
  • Increasing life expectancy - indicated by the relatively straight sides reaching the age of 70, followed by a good proportion of people living much longer
  • Decreasing death rate - indicated by the relatively straight sides reaching the age of 70
  • Low infant mortality - hardly any change between 0-9 years
  • Larger working age population - 15 to 69 represents a large proportion of the population
     

Example 3 - Japan As A More Economically Developed Country (MEDC)
 

Population Pyramid - Japan 

• This population pyramid indicates
  • Decreasing birth rate - indicated by decreasing population levels from age 29
  • Increasing life expectancy - indicated by the relatively straight sides reaching the age of 74, followed by a good proportion of people living much longer
  • Death rate is higher than the birth rate due to the ageing population
  • Low infant mortality
  • Ageing population - older dependent population with large proportion of the population older than 40
     

• Population changes can have major impacts within the economy resulting in changes to consumption, production, lifestyle, standards of living & government policies (fiscal, monetary & supply-side)
   
• Typical changes that occur are
  
  • Progressively ageing populations as economies develop
  • Falling birth rates as economies develop
  • Swings in net migration as influenced by war, famine, natural disasters & government policy
     

Ageing Populations

• Many developed economies are experiencing ageing populations & an increase in the older dependent population
• The implications of this include
  • Increased pension payments by governments
  • Increased need for care homes (public & private)
  • Increased pressure on the healthcare service & social care results in higher government spending
  • It also results in a smaller labour force & often Governments collect less tax
  • Firms suffer worker shortages
  • Labour shortages result in increased wage costs for firms
      

Falling Birth Rates

• Falling birth rates have the following impact on an economy
  • School closures due to fewer children
  • Future labour shortages 
  • Governments typically put in place incentives that encourage families to have more children
  • Governments may change the migration laws to encourage immigration so that labour shortages are prevented
    • Excessive immigration can change the nature & culture of different regions within a country
       

Migration

• In some countries migration can lead to an imbalance in the population structure e.g. the UAE has significantly more males than females 
• Rapid population growth caused by migration can lead to
  • Increased pressure on services such as healthcare & schools resulting in increased costs for government
  • A shortage of housing which generates social issues in society
  • Increased traffic congestion which is a negative externality
  • Increased water & air pollution which are negative externalities
  • Food shortages