top of page

Aggregate Expenditure Model

MPC, MPS, APC and APS

Topic Menu
Content Contributors
Christian Bien Portrait_edited.jpg

Christian Bien

Learning Objectives

tutorial.png

one.png
Marginal Propensity to Consume and Marginal Propensity to Save
Slide1.jpeg

The MPC makes up the gradient of the consumption line and the MPS makes up the gradient of the savings line in the consumption function.

two.png
Marginal Propensity to Consume
Slide2.jpeg

The Marginal Propensity to Consume (MPC) measures the increase in household consumption from an increase in household income. To calculate MPC: MPC = (Change in Consumption)/(Change in Disposable Income)

two.png
Can you calculate the MPC from the model below?
Slide2.jpeg

Answer: Change in Consumption (Consumer Spending): = 600-500 = 100 Change in Disposable Income: = 900-500 = 400 MPC: = 100/400 = 0.25

two.png
Average Propensity to Consume (APC)
Slide2.jpeg

Average Propensity to Consume measures the proportion of income spent on consumption. 

APC = Total Consumption/Total Disposable Income 


Can you find what the APC is from figure 1? 




Answer: Total Consumption = 600 Total Disposable Income = 900 APC = 600/900 = 0.67 Note: As income increases, the APC decreases.

two.png
Marginal Propensity to Save
Slide2.jpeg

Marginal Propensity to Save (MPS) measures the increase in savings from a given increase in household income. 


MPS = (Change in Savings)/(Change in Disposable Income) OR MPS = 1 - MPC 


Can you find what the MPS is from figure 2? 


Answer: 

Method 1 

Find MPC Change in Consumption = 625-500 = 125 

Change in Disposable Income = 1000-500 = 500 MPC = 125/500 = 0.25 

MPS = 1 -0.25 = 0.75 


Method 2 

Find MPS Change in Savings = 375 - 0 

(Note: the savings level at a disposable income of 500 is 0) = 375 

Change in Disposable Income = 1000-500 = 500 MPS = 375/500 = 0.75

two.png
Average Propensity to Save (APS)
Slide2.jpeg

Average Propensity to Save (APS) measures the total proportion of income that is saved. 


APS = Total Savings/ Total Income 


Can you find the APS of figure 2? 



Answer: 

Total Savings = 375 

Total Income = 1000 

APS = 375/1000 = 0.375 

Note: As income increases, the APS increases.

two.png
Slide2.jpeg
two.png
Slide2.jpeg
Consumption
Consumption Function
MPC, MPS, APC and APS
Investment
Government Expenditure
Net Exports
Aggregate Expenditure Model
Multiplier Process
bottom of page