Modern monetary policy begins with an assumption that is so familiar it is rarely questioned: as an economy grows, the quantity of money should generally grow with it.
More people are working. More goods are being produced. More transactions are taking place. It therefore seems intuitive that an expanding economy must require an expanding supply of money.
Economist Murray N. Rothbard challenged that assumption at its foundation. Across works including The Mystery of Banking, What Has Government Done to Our Money?, and Man, Economy, and State, Rothbard argued that money is fundamentally different from ordinary economic goods.
More food can feed more people. More houses can shelter more families. More machinery can expand productive capacity. But creating additional monetary units does not, by itself, create another house, automobile, factory, barrel of oil, bushel of wheat, or hour of productive labor.
“Any supply of money will be equally optimal with any other.”
— Murray N. Rothbard, The Mystery of Banking
Money Is Not the Same Thing as Wealth
Rothbard's argument begins with a distinction that is essential to monetary literacy: money and wealth are not the same thing.
Suppose an economy contains houses, automobiles, factories, food, energy, machinery, land, natural resources, and millions of hours of human labor. Those things constitute real economic wealth.
Now imagine that the number of dollars in that economy suddenly doubles.
Has the number of houses doubled?
Have twice as many automobiles appeared?
Are there suddenly twice as many factories, farms, machines, or skilled workers?
No. The economy contains the same real goods and productive resources it possessed before.
What has changed is the number of monetary units being used to express claims against those resources.
Rothbard therefore argued that increasing the quantity of money cannot make society as a whole wealthier merely by increasing the number of monetary units people possess. As prices adjust to the larger supply, the purchasing power represented by each individual unit changes.
Real wealth consists of goods, services, productive capacity, resources, and human knowledge. Money facilitates exchange between those things. Increasing the number of monetary units does not automatically increase the quantity of real wealth available to society.
How Much Money Is Enough?
This leads to the question Rothbard considered surprisingly easy to answer:
How much money does an economy actually need?
His answer was that there is no particular quantity that an economy must possess.
Imagine two otherwise identical economies.
One contains $100 billion of money.
The other contains $1 trillion.
If both economies possess the same real goods, productive capacity, population, and resources, the second economy is not automatically ten times richer simply because its monetary units are ten times more numerous.
Prices would instead adjust to the quantity of money available.
A house that costs $100,000 under one monetary arrangement might carry a much larger numerical price under another. Bread, labor, land, machinery, and every other good would likewise be denominated in different numbers.
The numbers change.
The underlying real economy does not.
The economy does not require a particular number of dollars. It requires a functioning medium of exchange whose purchasing power can adjust to the quantity available.
What Happens When the Economy Grows?
The strongest challenge to Rothbard's argument appears when the economy itself expands.
Suppose the quantity of money remains approximately unchanged while businesses become more productive, technology improves, the labor force expands, and the quantity of available goods increases.
Conventional monetary reasoning often assumes that the supply of money must rise alongside this expansion. Otherwise, it is argued, there will not be enough money available to purchase the additional production.
Rothbard rejected that conclusion.
If the amount of goods increases while the monetary stock remains the same, prices can simply adjust downward.
The same monetary units now command a greater quantity of goods.
Nothing requires every increase in production to be matched by a corresponding increase in the number of dollars.
Greater productivity can instead appear as greater purchasing power for each unit of money.
Economic growth does not necessarily require monetary growth. If production expands faster than the quantity of money, the adjustment can occur through falling prices and rising purchasing power rather than through creation of additional monetary units.
Why Falling Prices Were Not Automatically a Problem
This placed Rothbard sharply at odds with the modern tendency to treat almost every sustained decline in the general price level as something dangerous.
Consider an economy in which technological progress and improved productivity allow businesses to produce more goods with fewer resources.
If the monetary supply remains relatively stable, many prices may naturally fall.
To Rothbard, that need not represent economic failure.
It may represent abundance.
A worker earning the same number of monetary units could gradually purchase more food, clothing, transportation, tools, and other goods as productivity increased.
A saver holding money could likewise see that money command a greater quantity of goods over time.
Rothbard therefore distinguished between falling prices caused by growing productivity and a destructive monetary contraction caused by banking failures, debt liquidation, or a collapse in credit.
Both may be called “deflation,” but they describe very different economic processes.
The Angel Gabriel Thought Experiment
In The Mystery of Banking, Rothbard used a memorable thought experiment to demonstrate why simply increasing the supply of money cannot enrich society as a whole.
Imagine that a benevolent Angel Gabriel visits everyone while they sleep and magically doubles every person's money holdings.
Every wallet contains twice as much cash.
Every bank balance doubles.
Everyone awakens believing they are wealthier.
But the number of houses, automobiles, factories, farms, machines, and consumer goods has not changed.
Once people attempt to spend their larger balances, more money begins competing for the same available goods. Prices adjust.
The larger number of monetary units therefore cannot create the real prosperity everyone initially imagined.
Doubling everyone's dollars does not double society's wealth. It changes the number of monetary units competing for the same underlying goods.
Then Why Does Money Creation Matter?
This raises an important question.
If any quantity of money can perform the monetary function, and if prices eventually adjust to changes in quantity, why should anyone care when new money is created?
Because in the real world new money does not appear in everyone's possession at exactly the same moment.
It enters the economy through particular channels.
Banks may create new deposits through lending. Central banks may purchase securities. Governments may spend borrowed or newly monetized funds. Financial institutions, asset owners, contractors, borrowers, businesses, and workers may receive the resulting money at different stages.
The first recipients can spend the new money while many prices still reflect the previous monetary environment.
Later recipients may encounter higher prices before receiving any comparable increase in their own monetary income.
Monetary expansion therefore does not merely increase an abstract statistic called the money supply.
It changes relative purchasing power during the adjustment process.
This is closely related to what is commonly called the Cantillon Effect: new money enters at specific points, benefits some participants earlier than others, and changes prices unevenly as it moves through the economy.
Once money creation is understood as a process rather than an instantaneous increase in everyone's balance, the important questions become: Who receives the new money first? What do they purchase? Which prices rise first? And who encounters those higher prices before receiving additional income?
Money Creation Does Not Produce More Real Resources
Rothbard emphasized that increasing the supply of money differs fundamentally from increasing the supply of ordinary goods.
If farmers produce more wheat, society has more wheat.
If manufacturers produce more automobiles, society has more automobiles.
If engineers discover a method of producing electricity more efficiently, society has gained additional productive capacity.
But creating another billion monetary units does not create another billion monetary units' worth of houses, food, energy, machinery, or labor.
Instead, it changes the monetary claims through which people compete for those resources.
Some people may become considerably wealthier in the process.
That does not mean society as a whole has experienced an equivalent increase in real wealth.
Rothbard Did Not Require the Money Supply to Be Frozen Forever
Rothbard's position is sometimes simplified into the claim that he wanted the quantity of money permanently frozen at one exact number.
That is not quite correct.
Under the commodity-money system he favored, such as a market-based gold standard, the supply of monetary gold could still change.
New gold could be mined.
Gold could move between monetary and nonmonetary uses.
Coins could wear down or be lost.
Changes in the supply would therefore still occur through market activity.
His deeper objection was to the idea that monetary authorities must deliberately increase the supply according to some formula in order to accommodate economic growth, population growth, or a targeted price level.
Rothbard's argument was not that economists must discover the perfect quantity of money and freeze it forever. His argument was that no centrally determined “perfect quantity” is required in the first place.
What Price Stability Can Hide
Rothbard's reasoning also changes how we should think about “stable prices.”
Imagine that improvements in technology and productivity would, absent monetary expansion, cause consumer prices to fall by three percent.
Now imagine that money and credit are expanded enough to push prices upward by roughly three percent.
The observed price index might show almost no change.
Policymakers could describe that outcome as price stability.
Yet prices are higher than they would have been without the monetary expansion.
Consumers have been denied some of the purchasing-power gains that greater productivity would otherwise have delivered.
This was an important part of Rothbard's interpretation of monetary history. A stable consumer price index does not necessarily mean that monetary conditions themselves are stable.
Monetary expansion can be occurring at the same time productivity is exerting downward pressure on prices.
Money, Wealth, and Purchasing Power
Rothbard's argument ultimately requires us to separate three ideas that are frequently treated as though they were interchangeable:
Money. The medium through which exchange is conducted.
Wealth. The real goods, resources, productive assets, services, and knowledge available to society.
Purchasing power. The quantity of those goods and services that each unit of money can command.
These three things do not necessarily move together.
An economy can become wealthier while the number of monetary units remains unchanged.
An economy can create enormous quantities of currency while its productive capacity deteriorates.
A household's nominal bank balance can increase while the real purchasing power represented by that balance declines.
And a fixed or slowly changing quantity of money can support an economy producing vastly more goods than it produced decades earlier.
The number printed on a monetary unit tells us very little by itself. What matters economically is what that unit can command in real goods, services, labor, assets, and resources.
A Different Way to Think About Economic Growth
Modern monetary discussion often assumes that economic expansion should be accompanied by monetary expansion.
Rothbard asks us to reverse the question.
If an economy is becoming more productive, why must additional monetary units be created merely to prevent the prices of its goods from falling?
Why should greater abundance not appear as greater purchasing power for the people already holding money?
Why must productivity gains be partially absorbed by an expanding monetary supply rather than reflected in lower prices?
These questions do not require accepting every part of Rothbard's monetary theory.
They do require recognizing that a growing economy and a growing money supply are not synonymous.
Conclusion
Rothbard's monetary insight is deceptively simple.
An economy does not need a continually increasing number of dollars merely because it produces more goods.
Money is divisible.
Prices are adjustable.
Purchasing power can rise.
If production increases while the quantity of money remains relatively stable, the existing monetary units can simply command more.
That means prosperity does not have to appear as continuously rising nominal incomes and continuously rising nominal prices.
It can appear as something much simpler:
The same money buying more.
And once this distinction is understood, the question surrounding monetary expansion changes dramatically.
Instead of asking only whether the economy has “enough money,” we can ask whether new money was necessary at all.
We can ask who received it first.
We can ask which prices changed first.
We can ask who gained purchasing power during the adjustment and who lost it.
And most importantly, we can stop confusing an increase in the number of monetary units with an increase in real prosperity.
The economy does not become richer because it has more units of money. It becomes richer when it produces more of the things those monetary units can buy.
Rothbard did not argue that prosperity requires a permanently frozen number of monetary units. His more fundamental argument was that once money has been established, any quantity can perform its monetary function because prices and purchasing power can adjust. Economic growth therefore does not, by itself, create a necessity for continuous monetary expansion.