2.3.1.3 Theories of demand for money: The quantity theory, the Keynesian liquidity preference theory

Theories of demand for money provide insights into why individuals and businesses hold money and how the demand for money is influenced by various economic factors. Two prominent theories of demand for money are the Quantity Theory of Money and the Keynesian Liquidity Preference Theory.

1. Quantity Theory of Money: The Quantity Theory of Money is a classical economic theory that posits a direct and proportional relationship between the quantity of money in an economy and the general price level. It is often expressed by the equation:

MV = PT

Where: M = Money supply V = Velocity of money (the average number of times a unit of money changes hands in a year) P = Price level (average price of goods and services) T = Volume of transactions (the quantity of goods and services exchanged in the economy)

The Quantity Theory of Money assumes that the velocity of money (V) and the volume of transactions (T) are relatively stable in the short run. It also assumes that changes in the money supply (M) will lead to proportional changes in the price level (P).

According to this theory, an increase in the money supply (M) without a corresponding increase in the volume of transactions (T) would result in an increase in the price level (P). In other words, excessive growth in the money supply could lead to inflation. Conversely, a decrease in the money supply could lead to deflation.

2. Keynesian Liquidity Preference Theory: The Keynesian Liquidity Preference Theory was developed by John Maynard Keynes and emphasizes the demand for money as a function of the interest rate. According to this theory, individuals and businesses hold money for three main reasons:

a. Transactions Motive: Money is held for the purpose of conducting day-to-day transactions.

b. Precautionary Motive: Money is held as a precautionary measure to meet unexpected expenses or emergencies.

c. Speculative Motive: Money is held as a hedge against uncertainty, to take advantage of investment opportunities, or to time future investment decisions.

The demand for money in the Keynesian Liquidity Preference Theory is represented by the equation:

Md = L(Y, i)

Where: Md = Demand for money L = Liquidity preference function Y = Real income (output) i = Interest rate

According to Keynes, the demand for money is inversely related to the interest rate. When the interest rate is high, the opportunity cost of holding money is high, leading to a lower demand for money. Conversely, when the interest rate is low, the opportunity cost of holding money is low, leading to a higher demand for money.

Keynes argued that fluctuations in the demand for money could lead to changes in the money market equilibrium, affecting interest rates and, consequently, overall economic activity. In his theory, changes in the money supply by the central bank may not always have a significant impact on interest rates and economic activity if there are shifts in the demand for money due to changes in liquidity preferences.