The labour supply, or working population, is the members of a country's population that are willing and able to work. It includes those currently in employment or self-employment, and also those registered as unemployed. It excludes:
  1. Those in full-time education above the age of 16.
  2. Those below the age of 16.
  3. Those above retirement age.
  4. Those who have taken early retirement.
  5. Those who choose not to work (mainly married women).
  6. Those injured/disabled to a degree at which they are unable to work.

Labour supply is influenced by changes in the overall population, and also social factors. For instance, an increasing number of married women now seek employment; many young people continue full-time education after the age of 16; and early retirement is becoming more popular (something which is unfortunate due to our increasingly aging population in the west).