Demand Supply Theory of Money.ppt

Quantity Theory of Money / Monetary Transmission

Mechanism

Quantity Theory of Money Devised by Irving Fisher to explain the

link between money and the general price level

Based on the Fisher equation or the equation of exchange

This is the mathematical identity which relates aggregate demand to the total value of output (GDP)

M x V≡ P x T or (MV≡PY) M is the money supply V is the velocity of circulation (e.g. how

many times a £20 note is used to buy goods and services in year)

P is the general price level T stands for transactions and is

equivalent to output Y is the real value of national output

(real GDP)

Quantity Theory of Money: the theory that increase in the money supply will lead to increases in the price level

Velocity of circulation: the number of times the money supply changes hands in a year

Quantity Theory of Money Monetarists argue that the

velocity of circulation of money is broadly predictable and therefore assumed to be constant

T and Y (real GDP) tends to increase slowly over time and thus is assumed to be constant in any one year

If V and T (Y) are held constant then changes in the rate of growth of the money supply will lead directly to changes in the general price level

So as money supply increases so does inflation

Quantity Theory of Money: the theory that increase in the money supply will lead to increases in the price level

Velocity of circulation: the number of times the money supply changes hands in a year

To move towards the quantity theory of money, Fisher makes two key assumptions:

Fisher viewed velocity as constant in the short run. This is because he felt that velocity is affected by institutions and technology that change slowly over time.

Fisher, like all classical economists, believed that flexible wages and prices guaranteed output, Y, to be at its full-employment level, so it was also constant in the short run.

• Putting these two assumptions together lets look again at the equation of exchange: MV = PY

• If both V and Y are constant, then changes in M must cause changes in P to preserve the equality between MV and PY.

• This is the quantity theory of money: a change in the money supply, M, results in an equal percentage change in the price level P.

• We can further modify this relationship by dividing both sides by V: • M = (1/V) x PY • Since V is constant we can replace (1/V) with some constant, k, and when

the money market is in equilibrium, Md = M. So our equation becomes • Md = k x PY • So under the quantity theory of money, money demand is a function of

income and does not depend on interest rates.

II.  Keynes Liquidity Preference Theory

• In 1936, economist John M. Keynes wrote a very famous and influential book, The General Theory of Employment, Interest Rates, and Money. In this book he developed his theory of money demand, known at the liquidity preference theory.

Keynes believed there were 3 motives to holding money:

• Transactions motive. Money is a medium of exchange, and people hold money to buy stuff. So as income rises, people have more transactions and people will hold more money

• Precautionary motive. People hold money for emergencies (cash for a tow truck, savings for unexpected job loss). Since this also depends on the amount of transactions people expect to make, money demand is again expected to rise with income.

• Speculative motive. Money is also a way for people to store wealth. Keynes assumed that people stored wealth with either money or bonds. When interest rates are high, rate would then be expected to fall and bond prices would be expected to rise. So bonds are more attractive than money when interest rates are high. When interest rates are low, they then would be expected to rise in the future and thus bond prices would be expected to fall. So money is more attractive than bonds when interest rates are low. So under the speculative motive, money demand is negatively related to the interest rate.

• Keynes also modeled money demand as the demand for the REAL quantity of money (real balances) or M/P. In other words, if prices double, you must hold twice the amount of M to buy the same amount of stuff, but your real balances stay the same.

• So people chose a certain amount of real balances based on the interest rate, and income:10

• Liquidity preference function

M/P = f(i, Y) • The importance of interest rates in the Keynesian approach is the big difference between

Keynes and Fisher. With this difference also comes different implications about the behavior of velocity. Consider the two equations:

• MV = PY M/P = f (i, Y)

• so M = PY/V in the first equation. Substituting in the second equation: • Y/V = f(i, Y) or V = Y/(f(i,Y)). • This means that under Keynes' theory, velocity fluctuates with the interest rate. Since

interest rates fluctuate quite a bit, then velocity must too. In fact, velocity and interest rates will move in the same direction. Both are procyclical, rising with expansions and falling during recessions.

3. Baumol-Tobin Money Demand Model(s)

• These are further developments on the Keynesian theory

Variations in each type of money demand:• transactions demand is also affected by interest rates• so is precautionary demand• speculative demand is affected not only by interest rates

but also by relative risk free of available assets• Bottom line: demand for money is still positively related

to income and interest rates, but through multiple channels.