1. Ch.10- Aggregate Demand/Aggregate Supply
BY J.A.SACCO

2. C+I+G+(X-M) Let Us Build Our Model! Go Back to GDP
Chapter deals with why business activity fluctuates. A way to explain changes in output/unemployment/price level.
Go Back to GDP
C+I+G+(X-M)

3. C+I+G+(X-M) Let Us Build Our Model!
The components of GDP determine the value of total
expenditures. Consumers, Business Capital Investment,
Government, Foreign Markets make these spending decisions.

4. Answered by developing?
Let Us Build Our Model!
However, this much to simple an explanation. Two issues much be answered.
What determines the total amount that individuals, firms, governments, and foreigners want to spend?
What determines whether this spending will result in a higher output of goods/services (quantity) or higher prices (inflation)?
Aggregate Demand and Aggregate Supply
Answered by developing?

5. Let Us Build Our Model!
Aggregate Demand- TOTAL of all planned expenditures for the entire economy.
Aggregate Supply- TOTAL of all planned production for the entire nation.

6. Aggregate Demand Aggregate Demand Curve
A curve showing planned purchase rates for all goods and services in the economy at various price levels, all other things held constant
AD Curve is a shorthand way of illustrating the components of GDP.

7. Aggregate Demand C+I+G+(X-M)
Furthermore, AD Curve gives the total amount of Real Domestic Income (RDI) that will be purchased at each price level.
RDI = RGDP
Remember Circular Flow.

8. The Aggregate Demand CurveAD C
As the price level
rises, real GDP
demanded declines
140 B
Price Level/ GDP Deflator
120 A
100 1 2 3 4 5 6 7 8 9 10
Real GDP per Year
($ trillions)

9. The Aggregate Demand CurveAD A
As the price level
falls, real GDP
demanded increases
140 B
Price Level/GDP Deflator
120 C
100 1 2 3 4 5 6 7 8 9 10
Real GDP per Year
($ trillions)

10. Houston, We May Have a Problem!
Question- Why might the Law of Demand and the reasons for the downward slope of the demand curve not be applicable with aggregate demand.
Law of Demand (one good/service) states Pr QD Pr QD

11. Houston, We May Have a Problem!
Now dealing with the entire macroeconomy. Price level is the average price of all goods and services including wages. Remember, when the price level for goods/service increased the consumer would substitute other goods/services. Now there are no substititues.
The Law of Demand still applies and the aggregate demand curve is still downward sloping but for different reasons.

12. Downward Slope of the Aggregate Demand Curve?
What Happens When the Price Level Changes?
The Direct Effect: The Real-Balance Effect (wealth effect)
The Indirect Effect: The Interest Rate Effect
The Open Economy Effect: The Substitution of Foreign Goods

13. The Aggregate Demand Curve
The Real-Balance Effect
The change in the real value (purchasing power) of money balances when the price level changes.
While your nominal cash value stays the same, any change in the price level will cause a change in the real value (purchasing power) of cash balances.

14. The Aggregate Demand Curve
The Interest Rate Effect- Change in the price level indirectly effects the interest rate.
When price level increases, you go out to replace your lost purchasing power.
This greater demand for money causes the nominal interest rate to increase.
As interest rates rise this makes borrowing less attractive thus reducing the quantity of AD.
Lets look at a Price Level increase.
A decrease in the price level works in the opposite direction.

15. The Aggregate Demand Curve
The Open Economy Effect
Higher price levels result in foreigners’ desiring to buy fewer American-made goods while Americans desire more foreign-made goods (i.e. net exports fall)
This decline in net exports causes a decrease in the quantity of aggregate demand.

16. Review- A Change in the Price Level
Direct Effect/Real Balance Effect/Wealth Effect
If PL
Purchasing Power
Rate of Consumption
Quantity AD
If PL
Purchasing Power
Rate of Consumption
Quantity AD

17. Review- A Change in the Price Level
Indirect Effect/ Interest Rate Effect
If PL Demand for Money
Nominal Interest Rate
Consumption/ Investment
Quantity AD
Demand for Money
If PL

18. Review- A Change in the Price Level
Open-Economy Effect
If PL U.S. goods/services more expensive than foreign. Substitute foreign goods for U.S. goods/services.
Quantity AD
If PL U.S. goods/services cheaper than foreign. More U.S. goods/services purchased than foreign. Quantity AD

19. Review- A Change in the Price Level
Remember with any of these three reasons, it is a change in the Price Level. You are only moving up/down the AD curve.

20. Non- Price Determinants of Aggregate Demand
Any non-price-level change that effects any component of:
C + I + G + (X-M)
will cause a shift in the AD curve.

21. Non- Price Determinants of Aggregate Demand
Any non-price-level change that increases aggregate spending (on domestic goods) shifts AD to the right.
A drop in the foreign exchange value of the dollar
Increased security about jobs and future income
Improvements in economic conditions in other countries
A reduction in real interest rates (nominal interest rates corrected for inflation) not due to price level changes
Tax decreases (Fiscal Policy)
An increase in the amount of money in circulation (Monetary Policy)

22. Shifts in the Aggregate Demand Curve
Increase in
Aggregate
Demand AD
120
GDP Deflator 90
AD1 1 2 3 4 5 6 7
Real GDP per Year
($ trillions)

23. Determinants of Aggregate Demand
Any non-price-level change that decreases aggregate spending (on domestic goods) shifts AD to the left.
A rise in the foreign exchange value of the dollar
Decreased security about jobs and future income
Declines in economic conditions in other countries
A rise in real interest rates (nominal interest rates corrected for inflation) not due to price level changes
Tax increases (Fiscal Policy)
An decrease in the amount of money in circulation (Monetary Policy)

24. Shifts in the Aggregate Demand Curve
Decrease in
Aggregate
Demand AD
120
GDP Deflator 90
AD1 1 2 3 4 5 6 7
Real GDP per Year
($ trillions)