Monetary Plumbing
How money actually gets created, expanded, and distributed in the modern system. Most of it has nothing to do with printing presses.
How Money Is Created
Most people assume that money is created by the government running a printing press. In reality, the vast majority of money in a modern economy is created by commercial banks when they issue loans. When a bank approves a mortgage, it doesn't reach into a vault and hand over someone else's savings — it creates new deposit money from nothing. The central bank sets the rules and the reserve requirements, but the commercial banking system does the actual expanding.
This process is called fractional reserve banking. Each bank holds only a fraction of its deposits as reserves and lends out the rest. That loan becomes someone else's deposit at another bank, which then lends most of it out again. One real deposit multiplies through the system into many times its original value.
How One Deposit Becomes Many
Follow $10,000 as it moves through the banking system. Each bank holds a fraction as reserves and lends the rest — creating new money with every cycle.
The reserve requirement is the fraction of each deposit a bank must hold. The rest can be lent out. The Fed sets this rate. Before 2020, it was 10%. It is currently 0%.
Initial Deposit: $10,000
You deposit your paycheck at First National Bank. This is real money — earned from work. Everything that follows is created by the banking system.
Deposit In
$10,000
Held as Reserves
$1,000
New Loan Created
$9,000
Sarah borrows $9,000. This money didn't exist before the loan was approved. The bank created it.
System Totals After 1 Round
Original Cash
$10,000
Total Deposits
$10,000
Total New Money
$9,000
Money Multiplier
1.0x
With a 10% reserve requirement, the theoretical maximum money multiplier is 10.0x — meaning $10,000 could eventually become $100,000 in total deposits across the banking system.
The key insight:
Only the original $10,000 was real money earned from productive work. Everything above that was created by the banking system through lending. Each loan creates a new deposit, which enables another loan, which creates another deposit.
The borrowers all owe real debt with real interest — but the money they borrowed was created at the moment the loan was approved. This is how the modern money supply expands: not through printing presses, but through the banking system's ability to create credit.
At 10%, which was the U.S. requirement before March 2020, one dollar of deposits could theoretically support ten dollars of total money in the system. The Fed dropped the requirement to 0% during COVID — meaning there is no legal limit on this expansion.
Why This Matters for Prices
When the banking system can multiply deposits by 10x, 20x, or even more, the total money supply grows far beyond what was originally earned through productive work. All that new money competes for the same pool of real goods and services. The result: prices rise — not because goods got scarcer, but because money got more abundant.
And this is just one channel of monetary expansion. Government deficit spending, central bank asset purchases (quantitative easing), and the shadow banking system all add additional layers of money creation on top of this basic mechanism.
Quantitative Easing: The Central Bank Layer
Fractional reserve banking is the base layer. On top of it sits the central bank, which has its own tools for expanding the money supply. The most significant in recent history is quantitative easing (QE) — the process by which the Federal Reserve buys government bonds and mortgage-backed securities from banks, paying with newly created reserves.
Between 2008 and 2014, the Fed's balance sheet grew from about $900 billion to $4.5 trillion. Then between March 2020 and early 2022, it roughly doubled again to nearly $9 trillion. Each dollar of those purchases injected new base money into the banking system — reserves that banks could then multiply through lending.
The stated purpose is to lower interest rates and stimulate borrowing. The side effect is an enormous expansion of the monetary base that, once velocity picks up, translates into higher prices throughout the economy.
Government Deficit Spending
When the federal government spends more than it collects in taxes, the difference is covered by issuing Treasury bonds. These bonds are purchased by banks, pension funds, foreign governments — and increasingly, by the Federal Reserve itself. When the Fed buys Treasuries, it pays with newly created money. The government spends that money into the real economy through salaries, contracts, transfer payments, and stimulus checks.
This is the mechanism that most directly puts new money into people's hands. During 2020 and 2021, trillions of dollars in stimulus payments, expanded unemployment benefits, and PPP loans flowed directly to households and businesses — funded largely by Treasury issuance that the Fed absorbed. The money supply surged, and within 12 to 18 months, so did prices.
The Shadow Banking System
Traditional banks aren't the only entities that create credit. The "shadow banking" system — money market funds, hedge funds, repo markets, special purpose vehicles — extends the same multiplier logic outside the regulated banking system. The repo market alone handles over $4 trillion in daily transactions, with participants borrowing and re-lending securities in chains that create effective money supply growth.
This is why money supply figures like M2 only capture part of the picture. The total volume of credit and credit-like instruments circulating in the economy is far larger than what shows up in official monetary aggregates. The plumbing runs deeper than most people realize.
Zero Reserve Requirements
In March 2020, the Federal Reserve took a step that received remarkably little public attention: it reduced the reserve requirement for all depository institutions to 0%. Banks were no longer required to hold any fraction of deposits in reserve. In theory, this removed the mathematical ceiling on the money multiplier.
In practice, banks still hold reserves for liquidity management and to meet other regulatory requirements. But the symbolic and practical significance is worth noting: the primary constraint on money creation shifted from a hard reserve ratio to the much softer constraint of banks' own risk appetite and capital requirements. The guardrails became discretionary rather than mandatory.
Who Gets the Money First
Perhaps the most important — and least discussed — aspect of monetary expansion is that new money doesn't arrive everywhere at once. It enters through specific channels: bank lending desks, government contractor payments, bond trading floors, mortgage originators. The first recipients get to spend new money at yesterday's prices. By the time that money circulates to wages, rents, and groceries, prices have already adjusted upward.
This is the Cantillon Effect, named after the 18th-century economist Richard Cantillon, who first described how money injection points determine who benefits and who pays the cost. It explains why periods of monetary expansion tend to widen wealth inequality: asset owners (who are closest to credit creation) see their holdings rise in value, while wage earners and savers see their purchasing power erode.
The plumbing of the monetary system isn't just a technical detail. It determines who wins, who loses, and how fast you have to run just to stay in place.