This is the fifth in a series of posts about Modern Monetary Theory, based on the text by Mitchell, Wray and Watts. If you have not seen the earlier posts, I recommend that you start at the beginning.
What is money?
In modern economies, money is not a thing, but “a unit of account in which we keep track of debits and credits.” The sovereign state specifies the accounting unit, in our case the dollar, when it issues a currency. It has value not because it is backed by anything tangible, but mainly because the state accepts it as payment for people’s tax liabilities. That forces people to keep records in dollars for any transactions with tax implications. Once people are using the currency to track their transactions, it transcends anything physical. Money includes the paper dollars in your wallet, but it also includes all the accounting entries that record exchanges and show that someone has a dollar-denominated claim on someone else.
The dollar no longer has any fixed value. Since 1971, when the U.S. went off the gold standard, the value of the dollar has fluctuated according to its supply and demand in global financial markets.
According to Modern Monetary Theory, the creation of money is driven primarily by the demand for loans. When Meili extended credit to Thelma to buy stuff at her yard sale (see the previous post), the loan became a financial asset for Meili and a liability for Thelma, whether recorded in an I.O.U., a ledger, or in their respective memories. That kind of personal loan is at the bottom layer of the “pyramid of liabilities” that constitutes the monetary system. At a higher level, when a bank makes a business loan, it creates the money by crediting the business’s checking account. It also records the account balance as a liability for the bank, since it represents the bank’s obligation to accept checks drawn on the account. The loan itself is an asset for the bank, but a liability for the business, since the business is obligated to repay it.
Bank reserves
But doesn’t the bank have to have the money sitting in its vault before it can loan it out? No it doesn’t. It only has to have a small fraction of it in cash reserves, and most of those are held not in its vault but in an account with the central bank, in our case the Federal Reserve. The local bank doesn’t need much cash on hand on any given day, since it has deposits and loan payments coming in as well as withdrawals going out.
Modern Monetary Theory does not accept the notion that the reserves put a limit on the bank’s ability to lend, so that loan activity is limited by the existing supply of money. Banks respond to an increased demand for loans by finding the additional money they need to keep in reserve, whether by selling assets or borrowing from other banks or from the Federal Reserve. They make a profit by borrowing money at an “interbank” rate of interest and then charging their customers a somewhat higher rate.
The Federal Reserve stands at the top of the “pyramid of liabilities.” It is the “monopoly supplier of reserves.” Its operations accommodate the demand for money to lend, but only within limits because of the Fed’s responsibility to control inflation.
Inflation and interest rates
The Federal Reserve tries to control inflation by setting a target for the interest rate on interbank loans. Since the banks mark up this rate to make a profit when they lend to customers, this rate also affects interest rates for mortgages, business loans, and so forth. The Fed’s aim is to set rates high enough to discourage borrowing and spending when prices are rising too fast, and low enough to encourage borrowing and spending when inflation is low and the economy is growing too slowly. The Fed keeps a constant watch on actual interbank borrowing to see if the rates on interbank loans are deviating from the target. That happens because of fluctuations in the reserves held by the banks.
When banks are short of reserves, the shortage may drive the interbank rate up. (Banks are willing to pay more to borrow, or they can charge more to lend.) The Federal Reserve can alleviate the shortage by injecting cash into the system with purchases of bonds or other assets from banks. When an excess of reserves drives the interbank rate below the Fed’s target, it can drain reserves from the system by selling bonds or other assets to banks.
Treasury spending and lending
When the U.S. Treasury spends money authorized by the federal budget, it also creates money for the economy, for example by crediting the account of a building contractor. When it taxes, it removes money from the economy. When it spends more than it taxes, the excess money increases disposable income and boosts aggregate demand.
Deficit spending can be a source of inflation, however, by pushing up the market demand for goods and services without adding to the supply, especially if the economy is already running near capacity. The government spending went to produce a public good, such as a new highway, but it didn’t add to the supply of consumer goods that people can buy. By issuing Treasury bonds, the Treasury drains excess cash from the system and replaces it with I.O.U.s. People who buy the bonds are saving rather than spending.
Notice that I did not say that the government had to issue bonds in order to borrow the money before it could spend it, like a consumer using a credit card. In principle, the sovereign state has the power to create money when it spends without draining that money back out again through taxation or bond sales. Selling bonds is mainly a prudent measure to ward off inflation. For that reason, Modern Monetary Theory considers it a part of monetary policy more than fiscal policy, which is concerned more with taxing and spending.
The Federal Reserve does not buy Treasury bonds directly from the Treasury, but it can buy and sell them on the secondary market. Those buys and sells are an important way of adjusting bank reserves, as described above. Although the Federal Reserve has a degree of independence from the Treasury, in practice they work together to control inflation.
A tight monetary policy keeps interest rates high enough to discourage too much borrowing and spending. Experience has shown that it can be effective in controlling inflation. The downside is that it can slow economic growth and keep the economy running below capacity. The holy grail for economists would be a set of government policies that would promote both full employment and low inflation. Modern Monetary Theory tries to develop such a policy.
Beneath the Surface 