1. Monetary Theory and Policy
Demand and supply of money
The supply of money and the equilibrium interest rate
The monetary transmission mechanism
The Quantity theory of money
The record of monetary policy

2. The money market
Earlier we said that the interest rate (i) influences aggregate spending—specifically investment and consumption. However, we have yet to develop a theory of the interest rate
The interest rate is governed by the demand and supply of money.

3. Why do agents hold money?
To make planned expenditures/payments
To be prepared for unexpected expenditures/payments.
To store wealth.

4. The interest rate (i) measures the opportunity cost of holding money
The higher the interest rate, the more interest I give up by holding my wealth in money-- as opposed to an interest-bearing asset.

5. Demand for money
The money demand, Dm, slopes downward. As the interest rate falls, other things constant, so does the opportunity cost of holding money; the quantity of money demanded increases.
Interest rate Dm
Quantity of money

6. The supply of money
We assume that the Fed (or central banks generally) determines the supply of money

7. Effect of an increase in the money supply
Because the money supply is determined by the Federal Reserve, it can be represented by a vertical line.
Interest
rate i i’ Sm
S’m Dm
At point a, the intersection of the money supply, Sm, and the money demand, Dm, determines the market interest rate, i. a b
Following an increase in the money supply to S’m, the quantity of money supplied exceeds the quantity demanded at the original interest rate, i.
Quantity of
money M M’
People attempt to exchange money for bonds or other financial assets. In doing so, they push down the interest rate to i’, where quantity demanded equals quantity supplied. This new equilibrium occurs at point b.

8. Effects of an increase in the money supply on interest rates, investment, and aggregate demand
(a) Supply and demand
for money
Interest rate i i’
(b) Demand for
investment
(c) Aggregate demand
Price level P Sm
S’m Dm DI
AD’ AD a a b b b a
Money M M’
Investment I I’
Real GDP Y Y’
An increase in the money supply drives the interest rate down to i'.
This sets off the spending multiplier process, so the aggregate output demanded at price level P increases from Y to Y ‘
With the cost of borrowing lower, the amount invested increases from I to I‘.

9. Chain of cause and effect
M↑→i↓→I↑→AD↑→Y↑

10. The transmission mechanism
Fed open market purchase injects reserves into the banking system
Commercial banks, thrifts, etc. expand loans and deposits
The money supply increases
The equilibrium interest rate decreases
Consumption and investment increase
Real GDP, employment, and (perhaps ) the price level increase

11. Expansionary monetary policy to correct a contractionary gap
Potential output
LRAS
At a, the economy is producing less than its potential in the short run, resulting in a contractionary gap of $0.2 trillion.
Price
level
125
130
SRAS130
AD’
If the Federal Reserve increases the money supply by just the right amount, the aggregate demand curve shifts rightward from AD to AD’. A short-run and long-run equilibrium is established at b, with the pride level at 130 and output at the potential level of $14.0 trillion AD b a
Real GDP
(trillions of dollars)
14.0
13.8
Contractionary gap

12. Fed "target" rate
The FOMC sets a target for the “federal funds” rate, which is the rate that banks charge other banks for “borrowed” reserves.

13. Recent ups and downs in the federal funds rate
Global financial
crisis prompts
rate cuts
Rate cuts
to combat recession
Rate increased to slow red-hot economy
to limit
impact of
mortgage
defaults on economy
Rate increase to
head off inflation
Since the early 1990s, the Fed has pursued monetary policy primarily through changes in the federal funds rate, the rate that banks charge one another for borrowing and lending excess reserves overnight.

14. The Fed has cut rates sharply in 2008

15. The Equation of Exchange
Where
M is the quantity of money
V is the velocity of circulation
P is the price level
Y is real GDP

16. What is velocity (V)?
Velocity (V) is the average number of times per year a unit of money is spent for new goods and services. Let
(P  Y) is nominal GDP. Let P = 1.25; Y = $8 trillion; and M= $2 trillion. Thus:
Or, V = 5

17. Money and Aggregate Demand in LR
Velocity depends on
Customs and convention of commerce
Innovations facilitate exchange
Higher velocity
Frequency
The more often workers get paid
Stability (store of value)
The better store of value
Lower velocity

18. Equation of Exchange is Always True
The equation simply states that what is spent for new goods and services (M  V) is equal to the market value of new goods and services produced (P  Y).

19. Illustration Using the numbers on a preceding slide, we can see that
and
thus

20. “Monetarist” interpretation of the equation of exchange
The monetarists believe that price level changes (hence inflation) can be explained by changes in quantity of money
“Inflation is always and everywhere a monetary phenomenon.”

21. Example
Assume that V = 5 and is constant. Y is $8 trillion (also assumed to be constant). Initially, let M = $2 trillion

22. Our basic equation can be rearranged as follows:
Now solve for the price level (P):
Now let the money supply increase to $2.4 trillion. Notice that:
Thus we have:
Notice that:

23. Hence a 20 percent increase in the money supply causes the price level to increase by 20 percent. Monetarists put the blame for inflation squarely at the doorstep of the monetary authorities (in the U.S., the FED).

24. In the long run, an increase in the money supply results in a higher price level, or inflation
Potential output
LRAS
Price level
130
140
The quantity theory of money predicts that if velocity is stable, then an increase in the supply of money in the long run results in a higher price level, or inflation. Because the long-run aggregate supply curve is fixed, increases in the money supply affect only the price level, not real output.
AD’ AD b a
Real GDP
(trillions of dollars)
14.0

25. The velocity of M1 (a) Velocity of M1
M1 velocity fluctuated so much during the 1980s that M1 growth was abandoned
as a short-run policy target.

26. The velocity of M2 (b) Velocity of M2
M2 velocity appears more stable than M1 velocity, but both are now considered by the Fed as too unpredictable for short-run policy use.

29. German Hyperinflation and Money

30. Record indicates that nations with high rates of monetary growth also suffer high rates of inflation
A decade of annual inflation and money growth in 85 countries (average annual percent)

31. Targeting interest rate vs. targeting the money supply
An increase in the price level or in real GDP, with velocity stable, shifts rightward the money demand curve from Dm to D'm. Sm
S’m
Interest rate i’ i
D’m
If the Federal Reserve holds the money supply at Sm, the interest rate rises from i (at point e) to i ' (at point e'). e’ Dm e
e’’
Alternatively, the Fed could hold the interest rate constant by increasing the supply of money to S'm. The Fed may choose any point along the money demand curve D'm.
Quantity of money M M’

32. The Fed pulled on the string big time beginning in 1979—it was an anti-inflation strategy under Chairman Paul Volcker

33. Modeling Contractionary Monetary Policy
Price Level
Potential GDP AS
AD2
AD1 Y1
Real GDP

35. Conventional 30 year

36. Monthly payments on a $110,000 30 year mortgage note
Mortgage rate
Monthly Payment1 8%
$807.14
10%
$965.33
12%
$1,131.47
14%
$1,303.36
16%
$1,479.23
1 Does not include prorated insurance or property taxes.

37. Data in thousands of units

38. More recently, the Fed raised the federal funds rate six times between May 1999 and May 2000—from 4.75% to 6.5 %. Evidently unemployment was getting “too low.”

39. The FOMC reversed course in July 2000 and cut the funds rate 17 times, to a low of 1.00 percent in July 2003.

40. Inflation Monster
Beginning in 2004, and until summer of 2007, the FED was mainly concerned about inflation.