1. Module 18 Long-Run Aggregate Supply
By J.A.Sacco

2. Aggregate Supply
Knowing the position and shape of AD does not tell us anything about how the total dollar value of spending will be divided between output (real goods/services) and prices.
To determine this and thus the equilibrium level of real GDP must also look at aggregate supply.
Aggregate Supply- shows the relationship between planned rates of total production for the entire economy at various prices
Two Types of Aggregate Supply Curves
LRAS- Long Run
SRAS- Short Run

3. An Old Friend Revisited
What does the PPC have in common with the LRAS?

4. The PPC and the Long-Run Aggregate Supply Curve
Over time, the
production
possibilities curve
shifts outward.
LRAS 1
LRAS 2
This same principle
can be shown by
shifting the LRAS
curve to the right.
Capital Goods
Price Level 1 2 3 4 5 6 7 8 9 10
Consumption Goods
Real GDP per Year
($ trillions)

5. The Long Run Aggregate Supply Curve
A vertical line representing real output of goods and services based on full information and after full adjustments has occurred
Represents the real output of the economy under conditions of full employment?
Shows the potential level of output when resources are fully employed
LRAS is vertical
because all
resources fully
employed, output
can not be increased
at present time
Nothing changes ! What doesn’t change that makes the LRAS vertical?

6. Why the LRAS is Vertical
Key is Inputs do not change!!!
Technology does not Change- No change in technology, no change in output.

7. Why the LRAS is Vertical
Endowments of Resources Fixed- Amount/Quality of resources does not change. If these resources were being fully used then output will be maximum in the long run.

8. Why the LRAS is Vertical
Labor Productivity- No change in productivity means no change in output

9. Why the LRAS is Vertical
Population is Constant- No growth in population means no increase in the labor force/ no change in output.

10. Why the LRAS is Vertical
Why not increase price level of g/s to increase output in LRAS?
Full Adjustment to Price Level Changes- The price level has no effect on real GDP. If the price level for GDP rises, there will be a comparable rise in input prices. Cost of inputs part of the same price level. Therefore suppliers have no incentive to increase output.
Cost of Inputs =
Money received from Output
There is no profit . No incentive to produce anymore.
Input prices and output receipts all part of the
same price level. An implication of all of this is that
aggregate demand has no effect on LRAS and output.

11. LRAS- Review
Therefore the LRAS illustrates full information and full adjustment level of real output (inflation adjusted) of goods/services.
The LRAS is the level of real output that will continue being produced year after year, forever, if nothing changes.
Full employment level of real GDP. When economy reaches full employment, no further adjustments will occur unless a fundamental change occurs

12. Shifts in the LRAS Permanent Changes!
The LRAS shifts outward when one of the non-price level determinants change in the following way
Population increase
Resources increase
Technology improves
Permanent Changes!

13. Aggregate Demand and Long-Run Aggregate Supply
Because the LRAS is vertical, AD in the long run has no bearing on the level of output of real goods and services
If there is a shift of AD in the long run, the only thing that changes is the ___________ ?
price level (inflation).
Shift of AD in long run only leads to inflation!!!

14. Aggregate Demand and Long-Run Aggregate Supply
LRAS
Changes in AD
have no impact
on LRAS--only
on the price level
AD2
AD1
120
GDP Deflator 90 1 2 3 4 5 6 7
Real GDP per Year
($ trillions)

15. Aggregate Demand and Long-Run Aggregate Supply
In the long run, output of real goods/services is supply-side determined. Only shifts in LRAS will change long run levels of output not a shift of AD.