Unit 3: Consumption
Disposable Income (DI)
- Income after taxes or net income (take home)
 - What you have left over after you've payed all your bills
 
2 Choices
- With disposable income, households can either
 - Consume (spend money on goods and services)
 - Save (not spend money on goods and services)
 
Consumption
- Household spending
 - The ability to consume is constrained by
 - The amount of disposable income
 - The propensity to save
 - Do households consume is DI = 0??
 - Autonomous consumption
 - Dissaving
 
Saving
- Household NOT spending
 - The ability to save is constrained by
 - The amount of disposable income
 - The propensity to consume
 - Do households save if DI = 0?
 - NO
 
APC % APS (average propensity to consume and average propensity to save)
- APC + APS = 1
 - 1 - APS = APC
 - 1 - APC = APS
 - APC > 1 is Dissaving
 - -APS is Dissaving
 
MPC & MPS (Marginal propensity to consume and marginal propensity to save)
Marginal propensity to Consume
- The fraction of any change in disposable income that is consumed
 - △ in consumption / △ in DI
 - % of every extra dollar earned that is spend
 
Marginal propensity to Save
- The fraction of any change in disposable income that is saved
 - △ in saving / △ in DI
 - % of every dollar earned that is saved
 
MPC + MPS = 1
1 - MPC = MPS
1 - MPS = MPC
Spending Multiplier Effect
Spending Multiplier Effect
- An initial change in spending (C, Ig, G, Xn) cases a larger change in aggregate spending, or Aggregate Demand (AD).
 - Multiplier = △ in AD / △ in Spending
 - Change in spending = C, Ig, G, or Xn
 - Why does this happen??
 - Expenditures and income flow continuously which set off a spending increase in the economy.
 
Calculating the spending multiplier 
- Spending Multiplier can be calculated from the MPS or the MPS.
 - Multiplier = 1 / 1-MPC
 - = 1 / MPS
 - Multipliers are (+ )when there is an increase in spending and (-) when there is a decrease
 
Calculating the Tax Multiplier
- When the gov. taxes, the multiplier works in reverse
 - Why??
 - Because now money is leaving the circular flow
 - Tax Multiplier (note: its negative )
 - Tax Multiplier = -MPC / 1-MPC
 - = -MPC / MPS
 - If there is a tax CUT, then the multiplier is + because there is now more money in the circular flow
 
Comments
Post a Comment