4.10. Aggregate Expenditure (AE) Flashcards
(42 cards)
Aggregate Expenditure
Total amount spent in the economy at different levels of national income (GDP) in a given time period
Aggregate Expenditure Formula
AE = C + I + G + (X - M)
Aggregate Expenditure Curve
- Aggregate demand is derived from aggregate expenditure
- AD curve plots total spending at different price levels
- AE curve plots total spending at different income levels
Induced Expnditure
Spending that varies with income
- area above AE curve
Autonomous Expenditure
Spending that does not vary with income
- area below AE curve
Consumption meaning
spending by households on goods and services.
Determinants of consumption
- Disposable income (key determinant, analysed in detail next)
- Interest rates
- Availability of credit
- Confidence
- Expectations
- Wealth
Average Propensity to Consume (APC)
the proportion of disposable income that is consumed.
APC =
C / Y
Average Propensity to Save (APS)
the proportion of disposable income that is saved.
APS =
S / Y
Relationship between APC and APS
APC + APS = 1
APC and APS at low incomes
- APC is very high and APS is very low.
- Most / all income tends to be spent.
- Dissaving (consumption > income) might occur (through borrowing or using previous savings).
APC and APS as incomes rise
- APC starts to fall and APS starts to rise.
- Actual amount spent in total is higher but APC falls.
- Actual amount saved increases.
- Saving is a luxury.
Marginal Propensity to Consume (MPC)
the proportion of extra disposable income that is consumed.
MPC =
ΔC / ΔY
Marginal Propensity to Save (MPS)
the proportion of extra disposable income that is saved.
MPS =
ΔS / ΔY
Relationship between MPC and MPS
MPC + MPS = 1
MPC and MPS at low incomes
MPC is very high and MPS is very low.
Extra income tends to be spent.
MPC and MPS as incomes rise
- MPC is low and MPS is high.
- Extra income tends to be saved.
Consumption Function
relationship between income and consumption
Consumption Function Formula
C = a + bY
```
C = Consumption
a = autonomous consumption
b = MPC
Y = disposable income
bY = induced consumption
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Consumption Function Graph (DRAW DIAGRAM)
- y-axis = consumption
- x-axis = disposable income
C = Y graph drawn at 45 degrees
Consumption function graph also drawn, which overlaps C = Y