Aggregate demand

  • Aggregate Demand (AD) is
    ?
  • the total demand (level of expenditure) over a period of time.
  • Defined by the equation: (==AD = C + I + G + (X – M)==)
    • Aggregate demand = Consumption + Investment + Government expenditure + (Exports - Imports)

Components of AD

Consumption

  • is spending by households
  • Can be Autonomous (independent of income)
    • e.g. rent, groceries
  • Or induced (dependent consumption)
    • changes depending on disposable income levels
    • e.g. …
  • Largely influenced by:
    • consumer expectations
      • speculators expectations about future price rises and general goods availability
    • level of interest rates
    • the distribution of income
  • influenced by income (therefore indicates consumption):
  • Average propensity to consume (APC) is :: the proportion of total income that is spent on consumption.
  • Average propensity to save (APS) is :: the proportion of total income that is not spent, but is saved for future consumption.
  • Consumption represents ==60%== of AD in Australia.

Investment

  • is spending by firms

    • to increase productive capacity
  • influenced by:

    • the cost of inputs
      • Changes in interest rates
      • Changes in gov policies
      • profit levels (change in price and productivity of labour)
    • business expectations
      • changes in expected demand for their products
      • changes in general economic outlook
      • inflation
  • Investment represents (approx) ==15%== of AD

Government expenditure

  • is spending by local, state and federal governments

  • influenced by:

    • policy objectives of the government
      • (e.g. lower inflation & unemployment)
    • The general state of the economy
  • Government expenditure comprises of (approx) ==20%== of AD

Net foreign demand (exports - imports)

  • is expenditure by foreigners (on our exports), minus expenditure on foreign g/s (imports)
  • influenced by:
    • the global business cycle
    • exchange rate
    • commodity prices
  • Net foreign demand comprises (approx) ==20%== of AD