Money creation - Macroeconomics AP Study Notes

Money creation refers to the process by which the banking system increases the money supply beyond the physical currency issued by the central bank. This occurs through the fractional reserve banking system, where banks hold only a fraction of deposits as reserves and lend out the remainder.

Key Terms:

• Money supply (M1, M2, M3): Different measures of money in an economy, from narrow (cash + demand deposits) to broad (including savings accounts and time deposits)
• Reserve requirement (r): The minimum proportion of deposits banks must hold as reserves, set by the central bank
• Excess reserves: Deposits held beyond the required minimum, available for lending
• Money multiplier: The factor by which an initial deposit expands the total money supply

Essential Formula:

Money Multiplier (m) = 1/r where r = reserve ratio

Maximum deposit expansion = Initial deposit × (1/r)

For example, with a 10% reserve requirement (r = 0.10), the money multiplier is 1/0.10 = 10.

The Money Creation Process: When a bank receives a deposit, it keeps the required reserve percentage and loans the excess. The borrower spends this money, which gets deposited in another bank, creating new deposits. This deposit multiplication continues through successive rounds of lending. The process demonstrates how the banking system creates broad money (bank deposits) from narrow money (central bank reserves). Understanding this mechanism is crucial for analyzing monetary policy transmission and credit expansion in modern economies.

Think of money creation like a pyramid scheme, but legal and essential for economic growth. When you deposit £1,000 in your bank, you still consider it "your money" in your account. Yet the bank simultaneously lends £900 of it (with 10% reserves) to someone else, who also considers it "their money." Money has effectively been created from the same initial deposit.

Real-World Application: The 2008 Financial Crisis During the crisis, money creation reversed. As borrowers defaulted and banks feared losses, they stopped lending despite having excess reserves. The money multiplier collapsed from approximately 9 to below 4 in the US. Central banks responded with quantitative easing (QE), directly purchasing assets to inject reserves, but banks hoarded these reserves rather than lending. This illustrated that money creation requires both adequate reserves and banks' willingness to lend.

Modern Context: Digital Banking In the UK, approximately 97% of money exists as electronic bank deposits, not physical cash. When Barclays approves your mortgage, they don't transfer cash from savers—they simply credit your account electronically, creating new money. This is why central banks closely monitor credit growth as an inflation indicator.

The Multiplier Analogy: Imagine a bucket (the economy) being filled by a hose (central bank). The reserve requirement is like holes in the bucket. Lower reserves (bigger holes) mean more water circulates before draining out, creating a larger pool. Central banks adjust reserve requirements to control this "flow" of money through the economy.